Sani-Prime's Germicidal products are bactericidal, fungicidal, virucidal, and tuberculocidal disinfectant.
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First it breaks up biofilms, slimy colonies of bacteria that stick together to protect themselves from other bactericidal influences.
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I scrubbed his scalp with a soapy sponge, cleaned it with rubbing alcohol, and painted it with bactericidal iodine.
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The chemical is "bactericidal against major pathogens," and -- crucially -- not prone to developing a resistance in the bugs that it kills.
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Nisin was too good a bactericidal agent to keep to the dairy aisle, so food manufacturers added it to processed meats, dips, salad dressings, and soups.
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Bactericidal antibiotics kill bacteria; bacteriostatic antibiotics slow their growth or reproduction. Bactericidal antibiotics that inhibit cell wall synthesis: the beta-lactam antibiotics (penicillin derivatives (penams), cephalosporins (cephems), monobactams, and carbapenems) and vancomycin. Also bactericidal are daptomycin, fluoroquinolones, metronidazole, nitrofurantoin, co-trimoxazole, telithromycin. Aminoglycosidic antibiotics are usually considered bactericidal, although they may be bacteriostatic with some organisms.
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Depending on their concentration, they act as bacteriostatic or bactericidal agents.
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Aztreonam is bactericidal, but less so than some of the cephalosporins.
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Cefazolin is bactericidal, meaning it kills the bacteria rather than inhibiting their growth.
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Furthermore, the bactericidal power of the saponine is also effective against the louses.
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The effectiveness of our concept was demonstrated through bactericidal, fungicidal, sporicidal and virucidal test results.
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Their bactericidal, tuberculocidal, virucidal, fungicidal, pseudomonacidal and sporicidal action enable you to sterilize instantly and safely.
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TRPV4 activation by LPS was necessary and sufficient to induce nitric oxide production with a bactericidal effect.
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TRPV4 activation by LPS was necessary and sufficient to induce nitric oxide production with a bactericidal effect.
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In Phase 1, the ability of a product to demonstrate bactericidal, fungicidal or sporicidal activity is tested.
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Furthermore, some broad classes of antibacterial agents considered bacteriostatic can exhibit bactericidal activity against some bacteria on the basis of in vitro determination of MBC/MIC values. At high concentrations, bacteriostatic agents are often bactericidal against some susceptible organisms. The ultimate guide to treatment of any infection must be clinical outcome.
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Its bactericidal effects on Helicobacter pylori indicate a potential use for treating gastric ulcers in conjunction with NSAID therapy.
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The bactericidal power of blood-serum from both alcohol-drinking and non-drinking persons was determined by some experiments.
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Brasses, which were frequently used for doorknobs and push plates in decades past, also demonstrate bactericidal efficacies, but within a somewhat longer time frame than pure copper. All nine brasses tested were almost completely bactericidal (more than 99.9% kill rate) at 20 °C within 60–270 minutes. Many brasses were almost completely bactericidal at 4 °C within 180–360 minutes. The rate of total microbial death on four bronzes varied from within 50–270 minutes at 20 °C, and from 180 to 270 minutes at 4 °C.
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MC21-A (bromophene) is an bactericidal antibiotic isolated from the O-BC30 strain of a new marine bacterium, Pseudoalteromonas phenolica.
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In this simplified case, VCC "virtual survival" results are equivalent to the "survival" results of a traditional colony count bactericidal assay.
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Hsp33 protected many essential proteins from aggregation and inactivation due to HOCl, which is a probable mediator of HOCl's bactericidal effects.
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Marbofloxacin is a synthetic, broad spectrum bactericidal agent. The bactericidal activity of marbofloxacin is concentration dependent, with susceptible bacteria cell death occurring within 20–30 minutes of exposure. Like other fluoroquinolones, marbofloxacin has demonstrated a significant post-antibiotic effect for both gram–and + bacteria and is active in both stationary and growth phases of bacterial replication.Plumb DC (ed).
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PBP are responsible for cross-linking in the bacterial cell wall. They make peptide bonds between lysine and alanine. Cephalosporins bind into the reaction site of PBP’s rendering the enzyme unable to cross-link the bacterial wall giving bactericidal activity. The bactericidal effects of β-lactam antibiotics are achieved through inhibition of the bacterial cell wall synthesis.
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This shows that SDF as a compound has better bactericidal effects than silver ammonium nitrate and sodium fluoride (commonly found in toothpastes).
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In an inactive, UV-inducible photo-form they are harmless to bacteria cells, but are bactericidal after the activation with visible (amber) light.
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As of 2004, the distinction between bactericidal and bacteriostatic agents appeared to be clear according to the basic/clinical definition, but this only applies under strict laboratory conditions and it is important to distinguish microbiological and clinical definitions. The distinction is more arbitrary when agents are categorized in clinical situations. The supposed superiority of bactericidal agents over bacteriostatic agents is of little relevance when treating the vast majority of infections with gram-positive bacteria, particularly in patients with uncomplicated infections and noncompromised immune systems. Bacteriostatic agents have been effectively used for treatment that are considered to require bactericidal activity.
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Alone, both dalfopristin and quinupristin have modest in vitro bacteriostatic activity. However, 8-16 times higher in vitro bactericidal activity is seen against many gram-positive bacteria when the two streptogramins are combined . While quinupristin/dalfopristin is effective against staphylococci and vancomycin-resistant Enterococcus faecium, in vitro studies have not demonstrated bactericidal activity against all strains and species of common gram-positive bacteria.
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Semi-synthetics are antimicrobials that are derived from bacteria, but they are enhanced to have a greater effect. In contrast to both of these, synthetic are strictly made in the lab to combat pathogenicity. Each of these three types of antimicrobials can be classified into two subsequent groups: bactericidal and bacteriostatic. Bactericidal substances kill microorganisms while bacteriostatic substances inhibit microbial growth.
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It exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication. It acts by inhibiting the biosynthesis of cell-wall peptidoglycan.
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Cefditoren pivoxil may also reduce lung inflammation and epithelial damage by a non-bactericidal mechanism. It was patented in 1984 and approved for medical use in 1994.
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Cefdinir is a bactericidal antibiotic of the cephalosporin class of antibiotics. It can be used to treat infections caused by several Gram- negative and Gram-positive bacteria.
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The risk factors associated with BPF are not well known. However, it has been suggested that children under 5 years of age are more susceptible to BPF since they lack serum bactericidal activity against the infection. Older children and adults have much higher titers of bactericidal antibodies, which serve as a protective measure. Also children residing in warmer geographic areas have been associated with a higher risk of BPF infection.
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Material surfaces can exhibit bactericidal properties because of their crystallographic surface structure. In the mid 2000s it was shown that metallic nanoparticles can kill bacteria. The effect of a silver nanoparticle for example depends on its size with a preferential diameter of about 1-10 nm to interact with bacteria. In 2013, cicada wings were found to have a selective anti-Gram- negative bactericidal effect based on their physical surface structure.
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For example, a Cornell University student's prototype for a bactericidal jacket cost $10,000 alone, so it may be a long time before nanofabric clothing is on the market.
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Phanquinone is an organic compound. It is a yellowish solid derived by oxidation of 4,7-phenanthroline. It has been investigated as both antiprotozoal agent and for its bactericidal activity .
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Results from in vitro studies suggest that fatty acids, mainly polyunsaturated fatty acids, have a bactericidal effect against H. pylori, but their in vivo effects have not been proven.
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Mechanical deformation of the more or less rigid nanopillars found on the wing releases energy, striking and killing bacteria within minutes, hence called a mechano-bactericidal effect. In 2020 researchers have combined cationic polymer adsorption and femtosecond laser surface structuring to generate a bactericidal effect against both Gram-positive Staphylococcus aureus and Gram- negative Escherichia coli bacteria on borosilicate glass surfaces, providing a practical platform for the study of the bacteria-surface interaction.
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Telavancin (trade name Vibativ) is a bactericidal lipoglycopeptide for use in MRSA or other Gram-positive infections. Telavancin is a semi-synthetic derivative of vancomycin.Astellas, Inc. VIBATIV prescribing information, 9/2009.
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BPI fold-containing family B member 2 (BPIFB2) also known as bactericidal/permeability-increasing protein-like 1 (BPI-like 1) is a protein that in humans is encoded by the BPIFB2 gene.
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They are characterised by the presence of at least one proline. Cupiennin 2a is the best studied. It has a molecular mass of 3701.05 Da, and shows weak cytolytic, bactericidal and insecticidal activities.
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Molecular targets of antibiotics on the bacteria cell Protein synthesis inhibitors (antibiotics) Antibiotics are commonly classified based on their mechanism of action, chemical structure, or spectrum of activity. Most target bacterial functions or growth processes. Those that target the bacterial cell wall (penicillins and cephalosporins) or the cell membrane (polymyxins), or interfere with essential bacterial enzymes (rifamycins, lipiarmycins, quinolones, and sulfonamides) have bactericidal activities. Protein synthesis inhibitors (macrolides, lincosamides, and tetracyclines) are usually bacteriostatic (with the exception of bactericidal aminoglycosides).
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The following is a list of antibiotics. The highest division between antibiotics is bactericidal and bacteriostatic. Bactericidals kill bacteria directly, whereas bacteriostatics prevent them from dividing. However, these classifications are based on laboratory behavior.
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Daptomycin is bactericidal against Gram-positive bacteria only. It has proven in vitro activity against enterococci (including glycopeptide-resistant enterococci (GRE)), staphylococci (including methicillin-resistant Staphylococcus aureus), streptococci, corynebacteria and stationary-phase Borrelia burgdorferi persisters.
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AQP9 stimulates urea transport and osmotic water permeability; there are contradicting reports about its role in providing glycerol permeability. Aquaporin 9 may also have some role in specialized leukocyte functions such as immunological response and bactericidal activity.
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In 1940 Edwin C. White and Justina H. Hill discovered that a fungal strain of Aspergillus flavus growing in a surface culture on a tryptone-salt was capable of producing a bactericidal filtrate. It has also been shown to be a bactericidal for some Gram-negative as well as Gram-positive bacteria. Over the next few years they worked off this discovery and succeeded to isolate the active material in the crystalline form. In 1943 they managed to isolate this antibiotic compound and called it aspergillic acid primarily because of its origin and acidic properties.
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Difloxacin (INN), marketed under the trade name Dicural, is a second- generation, synthetic fluoroquinolone antibiotic used in veterinary medicine. It has broad-spectrum, concentration dependent, bactericidal activity; however, its efficacy is not as good as enrofloxacin or pradofloxacin.
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The oxygenated compounds produced by the lactoperoxidase system does not attack DNA and is not mutagenic and is known to be safe. Hypothiocyanite generated through this pathway displays broad spectrum bactericidal activity including potent antibacterial action on H. pylori.
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Anacardic acid is synergistic with anethole from the seed of anise (Umbelliferae) and linalool from green tea in vitro [Muroi & Kubo, p1782]. The totarol in the bark of Podocarpus trees is synergistic with anacardic acid in its bactericidal effects.
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Finafloxacin has demonstrated bactericidal activity against a range of bacterial pathogens, especially at acidic pH, with a post-antibiotic effect. Owing to its activity against both Gram-positive and Gram-negative bacteria, finafloxacin is classified as a broad-spectrum antibiotic.
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The different drugs in the regimen have different modes of action. INH are bacteriocidal against replicating bacteria. EMB is bacteriostatic at low doses, but is used in TB treatment at higher, bactericidal doses. RMP is bacteriocidal and has a sterilizing effect.
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TLR2 is also expressed by intestinal epithelial cells and subsets of lamina propria mononuclear cells in the gastrointestinal tract . In the skin, it is found on keratinocytes and sebaceous glands; spc1 is induced here, allowing a bactericidal sebum to be formed.
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This review presents also application of electrodiffusiophoresis for making bactericidal coatings. This effect has attracted new attention in 2010 with regard to microfluidics.Rica, R.A.; Bazant, M.Z. Electrodiffusiophoresis: Particle motion in electrolytes under direct current, Physics of Fluids vol. 22, p.
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Cefadroxil (formerly trademarked as Duricef) is a broad-spectrum antibiotic of the cephalosporin type, effective in Gram-positive and Gram-negative bacterial infections. It is a bactericidal antibiotic. It was patented in 1967 and approved for medical use in 1978.
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Clindamycin mechanism Clindamycin has a primarily bacteriostatic effect. At higher concentrations, it may be bactericidal. It is a bacterial protein synthesis inhibitor by inhibiting ribosomal translocation,Clindamycin University of Michigan. Retrieved July 31, 2009 in a similar way to macrolides.
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Structure of chlorhexidine, a bisbiguanide antiseptic. Bisbiguanides are a class of chemically related compounds known for their bactericidal properties. Generally considered to be of the generic formula: R1 R2 N.C(:NR6)NH.C(:NH)NH.CH2 X--(CH2)3 NH.C(:NH)NH.
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The minimum inhibitory concentration and minimum bactericidal concentration are used to measure in vitro activity antimicrobial and is an excellent indicator of antimicrobial potency. They don't give any information relating to time-dependent antimicrobial killing the so-called post antibiotic effect.
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Folate is necessary for the cell to synthesize nucleic acids (nucleic acids are essential building blocks of DNA and RNA), and in its absence cells will be unable to divide. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect.
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A bactericide or bacteriocide, sometimes abbreviated Bcidal, is a substance which kills bacteria. Bactericides are disinfectants, antiseptics, or antibiotics. However, material surfaces can also have bactericidal properties based solely on their physical surface structure, as for example biomaterials like insect wings.
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When formulated as a topical wound dressing, Iodosorb adsorbs exudate and particulate matter from the surface of granulating wounds and, as the dressing becomes moist, iodine is released. The product thus has the dual effect of cleansing the wound and exerting a bactericidal action. The bactericidal mechanism of cadexomer iodine is effective against Methicillin-resistant Staphylococcus aureus (MRSA) and may prevent MRSA proliferation in the wound bed. This is especially significant because bacteria populations have shown no sign of developing a resistance to iodine since it was first used for wound treatment in the middle of the 19th century.
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Owing to its high bactericidal activity in acidic environments, Bartoletti et al have speculated that finafloxacin may be useful in the treatment of urinary tract infections in the future. Finafloxacin's manufacturer, MerLion, has invested money in studying the use of finafloxacin for this indication.
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The bactericidal properties of arenicin-3 are responsible for its efficacy in inducing a 3-log reduction of E. coli bacterial load within 4 hours in a murine peritonitis model.andvang, D., Neve, S., et al. "NZ17074 - Pharmacokinetic and efficacy in mice" . Novozymes A/S.
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In 1942, Streptothricin, an antibiotic made by Actinomycetes, was found to be produced by a strain of S. lavendulae.Waksman SA, Woodruff HB. 1942. Streptothricin, a new selective bacteriostatic and bactericidal agent, particularly active against gram-negative bacteria. Proc Soc Exptl Biol Med. 49:207-210.
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Piperacillin is not absorbed orally, and must therefore be given by intravenous or intramuscular injection. It has been shown that the bactericidal actions of the drug do not increase with concentrations of piperacillin higher than 4-6 x MIC, which means that the drug is concentration-independent in terms of its actions. Piperacillin has instead shown to offer higher bactericidal activity when its concentration remains above the MIC for longer periods of time (50% time>MIC showing the highest activity). This higher activity present in continuous dosing has not been directly linked to clinical outcomes, but however does show promise of lowering possibility of resistance and decreasing mortality.
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In zebrafish, ZF- RNase-3 () must be cleaved by a protease (such as OmpT) in order to become activated and serve its bactericidal function. Through this evolved suicidal mechanism, the RNase mediates its own activation, since it is only cleaved in the presence of its bacterial target.
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Bacterial spores are considered to be resistant. Solutions are bacteriostatic or bactericidal according to their concentration. Gram-positive bacteria are generally more susceptible than gram-negative bacteria. Its activity depends on the surfactant concentration and also on the bacterial concentration (inoculum) at the moment of the treatment.
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The c-ANCA antigen is specifically proteinase 3 (PR3). p-ANCA antigens include myeloperoxidase (MPO) and bacterial permeability increasing factor Bactericidal/permeability-increasing protein (BPI). Other antigens exist for c-ANCA (atypical), however many are as yet unknown. Classical p-ANCA occurs with antibodies directed to MPO.
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Low concentration fluoride ions act as bacteriostatic therapeutic agent and high concentration fluoride ions are bactericidal. The incorporated fluorine makes enamel more resistant to demineralization and, thus, resistant to decay.Ross, Michael H., Kaye, Gordon I. and Pawlina, Wojciech (2003). Histology: A Text and Atlas. 4th edition, p. 453. .
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The Bs2 NLR gene from the wild pepper, Capsicum chacoense, was moved into tomato, where it inhibited pathogen growth. Field trials demonstrated robust resistance without bactericidal chemicals. However, rare strains of Xanthomonas overcame Bs2-mediated resistance in pepper by acquisition of avrBs2 mutations that avoid recognition but retain virulence.
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"Cat Scratch Disease in Connecticut—Epidemiology, Risk Factors, and Evaluation of a New Diagnostic Test." New England Aminoglycosides in lab tests showed some bactericidal activity. Bacteriostatic antibiotics aren’t able to easily get through to intracellular Bartonella so they aren’t recommended. In immunocompromised patients pain medication is often prescribed.
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A contact lens solution containing polyaminopropyl biguanide in combination with a borate buffer has been patented.Ogunbiyi et al. The solution is disinfecting and preservative and has a broad spectrum of bactericidal and fungicidal activity at low concentrations coupled with very low toxicity when used with soft-type contact lenses.
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2, Howell et al. 2011, Braissant et al. 2013), which assess mechanisms of action. Bactericidal action (see Bactericide) is indicated by an increased lag time as a function of increasing antibiotic concentration, while bacteriostatic action (see Bacteriostatic agent) is indicated by a decrease in growth rate with concentration.
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Further increasing their effect, when silver comes in contact with fluids, it tends to ionize which increases the nanoparticles' bactericidal activity. This has been correlated to the suppression of enzymes and inhibited expression of proteins that relate to the cell's ability to produce ATP. Although it varies for every type of cell proposed, as their cell membrane composition varies greatly, It has been seen that in general, silver nanoparticles with an average size of 10 nm or less show electronic effects that greatly increase their bactericidal activity. This could also be partly due to the fact that as particle size decreases, reactivity increases due to the surface area to volume ratio increasing.
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If this metabolic lag phase increases in the presence of the antimicrobial peptide, it could be considered a form of transient bacteriostatic activity in category 3, above, although other sources of transient bacteriostatic activity, such as a delay due to the time required for the repair of damaged cell structures such as cell walls or cell membranes, are possible. 5\. Bactericidal activity, or killing. Fewer surviving cells cause a delay in Tt as the survivors take longer to produce the same amount of turbidity through exponential growth. If all other processes causing increases in Tt are negligible, the VCC assay becomes a bactericidal assay and Tt can be used to enumerate viable bacteria by QGK.
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BBS has many uses because it is isotonic and has a strong bactericidal effect. It can be used to dilute substances and has applications in coating procedures. Additives such as [Polysorbate 20] and milk powder can be used to add to BBS's functionality as a washing buffer or blocking buffer.
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Cupiennins are a group of small cytolytic peptides from the venom of the wandering spider Cupiennius salei. They are known to have high bactericidal, insecticidal and haemolytic activities. They are chemically cationic α-helical peptides. They were isolated and identified in 2002 as a family of peptides called cupiennin 1.
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Bedaquiline blocks the proton pump for ATP synthase of mycobacteria. It is the first member of a new class of drugs called the diarylquinolines. Bedaquiline is bactericidal. ATP production is required for cellular energy production and its loss leads inhibition of mycobacterial growth within hours of the addition of bedaquiline.
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Those in dendritic cells have weaker bactericidal properties than those in macrophages and neutrophils. Also, macrophages are divided into pro-inflammatory "killer" M1 and "repair" M2. The phagolysosomes of M1 can metabolise arginine into highly reactive nitric oxide, while M2 use arginine to produce ornithine to promote cell proliferation and tissue repair.
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Morton, E.; Winters, J. and Smith, L. (2010). "An Analysis of Antiseptic and Antibiotic Properties of Variously Treated Mosses and Lichens" . University of Michigan Biological Station Usnic acid is the most commonly studied metabolite produced by lichens. It is also under research as an bactericidal agent against Escherichia coli and Staphylococcus aureus.
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These substrates include bromide and iodide and therefore lactoperoxidase can be categorised as a haloperoxidase. Another important substrate is thiocyanate. The oxidized products produced through the action of this enzyme have potent bactericidal activities. Lactoperoxidase together with its inorganic ion substrates, hydrogen peroxide, and oxidized products is known as the lactoperoxidase system.
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At physiologic pH, chlorhexidine salts dissociate and release the positively charged chlorhexidine cation. The bactericidal effect is a result of the binding of this cationic molecule to negatively charged bacterial cell walls. At low concentrations of chlorhexidine, this results in a bacteriostatic effect; at high concentrations, membrane disruption results in cell death.
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E. coli exposed to hypochlorous acid lose viability in less than 0.1 seconds due to inactivation of many vital systems. Hypochlorous acid has a reported of 0.0104–0.156 ppm and 2.6 ppm caused 100% growth inhibition in 5 minutes. However, the concentration required for bactericidal activity is also highly dependent on bacterial concentration.
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Formocresol has been used in pulpotomy procedures of the primary teeth since 80 years. Formocresol is both a bactericidal and devitalizing agent. It kills bacteria and converts the pulp tissue into inert compounds. This action fastens the vital pulp, maintaining them inert and conserves the primary tooth until it falls off physiologically.
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It is excreted into the urine and metabolized by the liver. It has an onset of 30 minutes and a half-life of 3.7 hours in newborns and 1.4 hours in adults. Amoxicillin attaches to the cell wall of susceptible bacteria and results in their death. It also is a bactericidal compound.
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Cefotiam is a parenteral second-generation cephalosporin antibiotic. It has broad-spectrum activity against Gram-positive and Gram-negative bacteria. As a beta-lactam, its bactericidal activity results from the inhibition of cell wall synthesis via affinity for penicillin-binding proteins. It was patented in 1973 and approved for medical use in 1981.
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Hyoscyamine is an antimuscarinic agent which reduces spasms of the urinary bladder's smooth muscles. Hexamethylenetetramine (also called methenamine) is hydrolyzed to formaldehyde, which acts as a bactericidal or bacteriostatic agent. Phenyl salicylate is a mild pain reliever from the class of nonsteroidal anti- inflammatory drugs (NSAIDs). Methylene blue is a weak antiseptic.
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165-71 Pharmacologically, Ichthammol has anti-inflammatory, bactericidal, and fungicidal properties. It is used to treat a variety of skin disorders as e.g. eczema, psoriasis, Acne rosacea and acne, and it decreases microorganisms in the area surrounding a skin condition. It is commonly used in 10% or 20% concentrate ointment, applied topically.
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The minimum bactericidal concentration (MBC) is the lowest concentration of an antibacterial agent required to kill a particular bacterium.Amyes S et al. Antimicrobial Chemotherapy: Pocketbook. CRC Press, 1996 Page 25 It can be determined from broth dilution minimum inhibitory concentration (MIC) tests by subculturing to agar plates that do not contain the test agent.
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Fleroxacin is a bactericidal drug that inhibits bacterial DNA gyrase and topoisomerase IV. Like other quinolones and fluoroquinolones the compound eradicates bacteria by interfering with DNA replication (bacterial DNA replication, transcription, repair and recombination). Fleroxacin is active against many Gram-positive and Gram-negative bacteria. It is especially active against Shigella species., Salmonella sp.
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Sisomicin (bactoCeaze or Ensamycin) is an aminoglycoside antibiotic, isolated from the fermentation broth of a new species of the genus Micromonospora. It is a newer broad-spectrum aminoglycoside most structurally related to gentamicin. Sisomicin is the most predictably active aminoglycoside against Gram-positive bacteria. Like most other aminoglycosides, sisomicin is bactericidal for sensitive clinical isolates.
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In 2002 a new family of peptides called cupiennins (cupiennin 1a, cupiennin 1b, cupiennin 1c, cupiennin 1d) was discovered from the venom. These proteins are all composed of 35 amino acid residues, and have high antimicrobial activities. It was subsequently discovered that the cupiennins are broad-spectrum bioactive compounds having bactericidal, insecticidal and haemolytic activities.
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Cefuroxime axetil, as a second generation cephalosporin ;that just as penicillins antibiotics, contains a β-lactam ring structure. Cephalosporins works as a bactericidal antibiotic; that by binding to penicillin-binding proteins (PBPs), inhibit the last step of the bacterial cell wall synthesis. Once the β-lactam ring binds to PBPs, cross-linking between peptidoglycan units is inhibited.
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Their antimicrobial spectrum of inhibition, bactericidal mode of action, relative tolerance to processing conditions (pH, NaCl, heat treatments) and the lack of toxicity towards eukaryotic cells enforces their role as biopreservatives in food. The evaluation of any new antimicrobial actives is done in meat by USDA which relies on the GRAS assessment by FDA among other suitability data.
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There are multiple chemotypes for each of the subspecies. Subspecies gracilis has two major chemotypes: thymol chemotype (maximum 68.1% )and linalool chemotype (maximum 82.3%). The essential oils produced from each respective chemotype are effective in vitro against some gram-negative and gram-positive strains. Depending on the concentration the essential oils can be bacteriostatic or bactericidal.
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Carbenicillin is a bactericidal antibiotic belonging to the carboxypenicillin subgroup of the penicillins. It was discovered by scientists at Beecham and marketed as Pyopen. It has Gram-negative coverage which includes Pseudomonas aeruginosa but limited Gram-positive coverage. The carboxypenicillins are susceptible to degradation by beta-lactamase enzymes, although they are more resistant than ampicillin to degradation.
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The intra-cellular granules of the human neutrophil have long been recognized for their protein-destroying and bactericidal properties. Neutrophils can secrete products that stimulate monocytes and macrophages. Neutrophil secretions increase phagocytosis and the formation of reactive oxygen compounds involved in intracellular killing. Secretions from the primary granules of neutrophils stimulate the phagocytosis of IgG-antibody-coated bacteria.
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Oxidative burst in phagocytes is most commonly associated with bacterial killing. However, macrophages, especially alveolar macrophages, usually produce far lower levels of ROS than neutrophils, and may require activation for their bactericidal properties. Instead, their transient oxidative burst regulates the inflammatory response by inducing cytokine synthesis for redox signalling, resulting in an influx of neutrophils and activated macrophages.
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Desosamine is a 3-(dimethylamino)-3,4,6-trideoxyhexose found in certain macrolide antibiotics (contain a high level of microbial resistance) such as the commonly prescribed erythromycin, azithromycin, clarithroymcin, methymycin, narbomycin, oleandomycin, picromycin and roxithromycin. As the name suggests, these macrolide antibiotics contain a macrolide or lactone ring and attached to the ring is desosamine which is crucial for bactericidal activity.
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Clinical isolates of S. aureus harboring genes which encode for lincosamide nucleotransferases have been reported. Genes lnuA and lnuB confer resistance to lincomycin, but not clindamycin. These genes, however, limit the bactericidal activity of clindamycin. This type of resistance is rare in S. aureus, but has been reported to be more prevalent in other bacteria strains.
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Some authors have noted that, despite its bacteriostatic effect in vitro, linezolid "behaves" as a bactericidal antibiotic in vivo because it inhibits the production of toxins by staphylococci and streptococci. It also has a post-antibiotic effect lasting one to four hours for most bacteria, meaning that bacterial growth is temporarily suppressed even after the drug is discontinued.
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The phagosome fuses with lysosomes to form a phagolysosome, which has various bactericidal properties. The phagolysosome contains reactive oxygen and nitrogen species (ROS and RNS) and hydrolytic enzymes. The compartment is also acidic due to proton pumps (v-ATPases) that transport H+ across the membrane, used to denature the bacterial proteins. The exact properties of phagolysosomes vary depending on the type of phagocyte.
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Macrophages and neutrophils are professional phagocytes in charge of most of the pathogen degradation, but they have different bactericidal methods. Neutrophils have granules that fuse with the phagosome. The granules contain NADPH oxidase and myeloperoxidase, which produce toxic oxygen and chlorine derivatives to kill pathogens in an oxidative burst. Proteases and anti-microbial peptides are also released into the phagolysosome.
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Plant growth promoting bacteria (PGPBs) often produce Nod factors (nodulation factors) that initiate nodule formation in plants. In addition to plant-bacterial interactions, bacteria often secrete bactericidal or fungicidal compounds into the phytobiome to reduce local competition for niches and resources. Additionally, organisms that feed on bacteria such as some species of algae and protists are attracted to these small signaling molecules.
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The lactoperoxidase system does not attack DNA and is not mutagenic. However, under certain conditions, the lactoperoxidase system may contribute to oxidative stress. It has been shown that lactoperoxidase in the presence of thiocyanate can trigger the bactericidal and cytotoxic effects of hydrogen peroxide under specific conditions, such as when hydrogen peroxide is present in the reaction mixtures in excess of thiocyanate.
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The greatest biocidal activity is associated with the C12 dodecyl and C14 myristyl alkyl derivatives. The mechanism of bactericidal/microbicidal action is thought to be due to disruption of intermolecular interactions. This can cause dissociation of cellular membrane lipid bilayers, which compromises cellular permeability controls and induces leakage of cellular contents. Other biomolecular complexes within the bacterial cell can also undergo dissociation.
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Isobutyl cyanoacrylate is an isomer of butyl cyanoacrylate. It is used in medical procedures either to close incisions and lacerations without the use of sutures, or as an adjunct to strengthen the suturing. This use is possible because it is a bactericidal liquid monomer which, in the presence of small amounts of moisture, rapidly polymerizes to form a strong adhesive.
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She investigated how the shape of quantum dots impacted their function and toxicity. She demonstrated that weathering quantum dots in acidic and alkaline conditions can increase the bactericidal activity due to the rapid release of cadmium and selenite ions. Her group worked on other nanomaterials, including fullerene C60. At Rice University, Colvin was appointed the Kenneth S. Pitzer- Schlumberger Professor of Chemistry.
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ROI generation by NADPH oxidase is an important bactericidal mechanism after FcR-mediated phagocytosis. PGE2 activates both Gs-coupled EP2 and EP4 receptors by ligation, stimulating cAMP production and subsequent activation of downstream cAMP effectors, PKA and Epac-1; both which in turn impair the phosphorylation and phagosomal membrane translocation of NADPH oxidase component, p47phox, thereby inhibiting the respiratory burst.
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HClO may oxidise cysteines and methionines via their sulfhydryl groups and sulfur groups respectively. The former leads to the formation of disulfide bonds, inducing protein crosslinking. Both oxidations result in protein aggregation, and ultimately, cell death. Sulfhydryl groups can be oxidised up to three times by three HClO molecules, forming sulfenic acids, sulfinic acids and R–SO3H, which are increasingly irreversible and bactericidal.
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Clofazimine is a weakly bactericidal dye that has some activity against M. leprae. Its precise mechanism of action is unknown but may involve mycobacterial DNA binding. Its oral absorption is quite variable, with 9 to 70% of the drug eliminated in the feces. Clofazimine achieves significant concentrations in tissues, including the phagocytic cells; it has a plasma half-life of 70 days.
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Colistin is a polycationic peptide and has both hydrophilic and lipophilic moieties. These cationic regions interact with the bacterial outer membrane, by displacing magnesium and calcium bacterial counter ions in the lipopolysaccharide. Hydrophobic/hydrophilic regions interact with the cytoplasmic membrane just like a detergent, solubilizing the membrane in an aqueous environment. This effect is bactericidal even in an isosmolar environment.
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Since the activity of antibacterials depends frequently on its concentration, in vitro characterization of antibacterial activity commonly includes the determination of the minimum inhibitory concentration and minimum bactericidal concentration of an antibacterial. To predict clinical outcome, the antimicrobial activity of an antibacterial is usually combined with its pharmacokinetic profile, and several pharmacological parameters are used as markers of drug efficacy.
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Antibiotics used in combination may also be antagonistic and the combined effects of the two antibiotics may be less than if one of the antibiotics was given as a monotherapy. For example, chloramphenicol and tetracyclines are antagonists to penicillins. However, this can vary depending on the species of bacteria. In general, combinations of a bacteriostatic antibiotic and bactericidal antibiotic are antagonistic.
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Van Dissel was born on 29 April 1957 in Amsterdam. He obtained his doctorate at Leiden University in 1987 with a thesis titled: "Divergent bactericidal activity of resident and activated macrophages for Salmonella typhimurium and Listeria monocytogenes". He became a professor of internal medicine, in particular infectious diseases, at Leiden University in 2000. In 2013 he succeeded as head of the .
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The nascent phagosome is not inherently bactericidal. As it matures, it becomes more acidic from pH 6.5 to pH 4, and gains characteristic protein markers and hydrolytic enzymes. The different enzymes function at various optimal pH, forming a range so they each work in narrow stages of the maturation process. Enzyme activity can be fine-tuned by modifying the pH level, allowing for greater flexibility.
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Meropenem is bactericidal except against Listeria monocytogenes, where it is bacteriostatic. It inhibits bacterial cell wall synthesis like other β-lactam antibiotics. In contrast to other beta-lactams, it is highly resistant to degradation by β-lactamases or cephalosporinases. In general, resistance arises due to mutations in penicillin-binding proteins, production of metallo-β-lactamases, or resistance to diffusion across the bacterial outer membrane.
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Much like the oral cavity, the upper and lower respiratory system possess mechanical deterrents to remove microbes. Goblet cells produce mucous which traps microbes and moves them out of the respiratory system via continuously moving ciliated epithelial cells. In addition, a bactericidal effect is generated by nasal mucus which contains the enzyme lysozyme. The upper and lower respiratory tract appears to have its own set of microbiota.
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Nitrofurantoin exerts greater effects on bacterial cells than mammalian cells because bacterial cells activate the drug more rapidly. It is not known which of the actions of nitrofurantoin is primarily responsible for its bactericidal activity. The broad mechanism of action for this drug likely is responsible for the low development of resistance to its effects, as the drug affects many different processes important to the bacterial cell.
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The minimum bactericidal concentrations (MBC) have been found to be equivalent or very close to the minimum inhibitory concentrations (MIC). Like other aminoglycosides, most clinical isolates of Pseudomonas aeruginosa remain susceptible to sisomicin. Resistance to sisomicin may be enzymatically or non-enzymatically mediated. Sisomicin is inactivated by the same enzymes as gentamicin, but it is active against many organisms that resist gentamicin by non-enzymatic mechanisms.
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By themselves, streptogramins A and B are bacteriostatic. However, when used in conjunction with one another, the streptogramins can inhibit bacterial growth and are bactericidal. Streptogramin A first binds to the peptidyl transferase domain of the 50s ribosomal subunit, preventing the early events of elongation. The binding of streptogramin A causes a conformational change that increases the ribosomal binding activity of streptogramin B 100-fold.
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This has been seen at sub-MIC levels of antibiotics. As such, it is increasingly important to determine the MIC in order to make the best choice in prescribing antimicrobials. MIC is used clinically over MBC because MIC is more easily determined. Minimum bactericidal concentration (MBC), which is the minimum antibacterial concentration resulting in microbial death, is defined by the inability to re-culture bacteria.
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The experimenters found that Mg(OAc)2 caused the best conformational change. MgSO4 and MgCl2 induced the effect slightly while the rest did not. When magnesium acetate is mixed with hydrogen peroxide it acts as a bactericidal. Magnesium acetate has been shown to be effective at ashing organic compounds in preparation for a fluorine analysis when high or low concentrations of fluorine are present.
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Cephalosporins are bactericidal and have the same mode of action as other β-lactam antibiotics (such as penicillins), but are less susceptible to β-lactamases. Cephalosporins disrupt the synthesis of the peptidoglycan layer forming the bacterial cell wall. The peptidoglycan layer is important for cell wall structural integrity. The final transpeptidation step in the synthesis of the peptidoglycan is facilitated by penicillin-binding proteins (PBPs).
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Modification of the surface charge of polymers has also proven to be an effective means of biofilm prevention. Based on the principles of electrostatics charged particles will repel other particles of like charge. The hydrophobicity and the charge of polymeric chains can be controlled by using several backbone compounds and antimicrobial agents. Positively charged polycationic chains enables the molecule to stretch out and generate bactericidal activity.
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Polyaminopropyl biguanide (PAPB) is a disinfectant and a preservative used for disinfection on skin and in cleaning solutions for contact lenses. It is also an ingredient in many deodorant bodysprays. It is a polymer or oligomer where biguanide functional groups are connected by hexyl hydrocarbon chains, with varying chain lengths. PAPB is specifically bactericidal at very low concentrations (10 mg/l) and is also fungicidal.
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Multiple alternatively spliced transcript variants encoding the same protein have been described for this gene but the full length nature of some transcripts is not yet known. Reg3A (UniProt Q0614 1) is a bactericidal C-type lectin that is constitutively produced in the intestine that has antibacterial properties against Gram-positive bacteria. Bacterial killing is mediated by binding to surface-exposed carbohydrate moieties of bacterial peptidoglycan.
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Lactoperoxidase-catalysed reactions yield short-lived intermediary oxidation products of SCN−, providing antibacterial activity. The major intermediary oxidation product is hypothiocyanite OSCN−, which is produced in an amount of about 1 mole per mole of hydrogen peroxide. At the pH optimum of 5.3, the OSCN− is in equilibrium with HOSCN. The uncharged HOSCN is considered to be the greater bactericidal of the two forms.
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The pituitary gland is required for protection against lethal effects of Salmonella typhimurium. Proc. Natl. Acad. Sci. USA 88:2274 2277. Further research by Kelley showed that growth hormone significantly improves survival of rats infected with S. typhimurium by increasing the bactericidal activity of macrophages and neutrophils. In the late 1980s, Kelley's group showed that this occurs because growth hormone activates macrophages and neutrophils to produce superoxide anion.
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Post-treatment relapse rates remain low. Resistance has been reported in several countries, although the number of cases is small. People with rifampicin-resistant leprosy may be treated with second line drugs such as fluoroquinolones, minocycline, or clarithromycin, but the treatment duration is 24 months due to their lower bactericidal activity. Evidence on the potential benefits and harms of alternative regimens for drug-resistant leprosy is not yet available.
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Malakoplakia is thought to result from the insufficient killing of bacteria by macrophages. Therefore, the partially digested bacteria accumulate in macrophages and leads to a deposition of iron and calcium. The impairment of bactericidal activity manifests itself as the formation of an ulcer, plaque or papule.Malakoplakia is associated with patients with a history of immunosuppression due to lymphoma, diabetes mellitus, kidney transplantation, or because of long-term therapy with systemic corticosteroids.
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Nalidixic acid is effective primarily against gram- negative bacteria, with minor anti-gram-positive activity. In lower concentrations, it acts in a bacteriostatic manner; that is, it inhibits growth and reproduction. In higher concentrations, it is bactericidal, meaning that it kills bacteria instead of merely inhibiting their growth. It has historically been used for treating urinary tract infections, caused, for example, by Escherichia coli, Proteus, Shigella, Enterobacter, and Klebsiella.
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Didecyldimethylammonium chloride (DDAC) is an antiseptic/disinfectant that is used in many biocidal applications. It causes disruption of intermolecular interactions and dissociation of lipid bilayers. It is a broad spectrum bactericidal and fungicidal and can be used as disinfectant cleaner for linen, recommended for use in hospitals, hotels and industries. It is also used in gynaecology, surgery, ophthalmology, pediatrics, OT, and for the sterilization of surgical instruments, endoscopes and surface disinfection.
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Should some bacteria survive a chemical attack, they give rise to new generations composed completely of bacteria that have resistance to the particular chemical used. Under a sustained chemical attack, the surviving bacteria in successive generations are increasingly resistant to the chemical used, and ultimately the chemical is rendered ineffective. For this reason, some question the wisdom of impregnating cloths, cutting boards and worktops in the home with bactericidal chemicals.
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It has mostly been studied by the aforementioned Pelling Group. Chitosan is derived from chitin in a process known as alkaline deacetylation (substituting out certain amino acid groups). The degree of this process determines the physical and chemical properties of the chitosan. Chitosan has antibacterial properties, in particular, it has bactericidal effects on planktonic bacteria and biofilms and a bacteria static effects on gram negative bacteria like E.coli.
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The intracellular granules of the human neutrophil have long been recognized for their protein-destroying and bactericidal properties.Paoletti p. 62 Neutrophils can secrete products that stimulate monocytes and macrophages; these secretions increase phagocytosis and the formation of reactive oxygen compounds involved in intracellular killing. Neutrophils have two types of granules; primary (azurophilic) granules (found in young cells) and secondary (specific) granules (which are found in more mature cells).
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It has proven very popular as a root-end filling material and has shown generally high success rates. MTA produces a high pH environment, which is bactericidal, and may stimulate osteoblasts to produce bone to fill in any defects caused by infection. Modified versions of zinc oxide eugenol cement (ZOE) cement, such as IRM or Super EBA, have high compressive strength, high tensile strength, neutral pH, and low solubility.
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George D. Heist of Philadelphia, a scientist who gave the first > description of complement system deficiency and who himself died of > meningococcal meningitis. The paper of Heist et al. (1922) stated: 'The > subsequent history of man 'H' illustrates the lack of resistance to > meningococcal infection that accompanies absence of bactericidal power > against the meningococcus. Man 'H' was no other than Dr. George D. Heist, > the chief author of this paper.
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PBP2a is known to give staphylococci resistance to other β-lactam drugs and PBPx does the same for pneumococci. Ceftobiprole also has an aminothiazoylhydroxyimino side chain at the C-7 position which is known to give good resistance to β-lactamase from S. aureus. Together these active groups make Ceftobiprole bactericidal to MRSA. Ceftobiprole has poor water solubility and is therefore administered intravenously as an ester prodrug called Ceftobiprole medocaril.
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The exposure to these reactive species in the respiratory burst results in pathology. This is due to oxidative damage to the engulfed bacteria. Notably, peroxynitrite is a very strong oxidising agent that can lead to lipid peroxidation, protein oxidation, protein nitration, which are responsible for its bactericidal effects. It may react directly with proteins that contain transition metal centers, such as FeS, releasing Fe2+ for the Fenton reaction.
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NO is also responsible for endothelium- derived relaxing factor activity regulating blood pressure. In macrophages, NO mediates tumoricidal and bactericidal actions, as indicated by the fact that inhibitors of NO synthase (NOS) block these effects. Neuronal NOS and macrophage NOS are distinct isoforms. Both the neuronal and the macrophage forms are unusual among oxidative enzymes in requiring several electron donors: flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), NADPH, and tetrahydrobiopterin.
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There are several activated forms of macrophages. In spite of a spectrum of ways to activate macrophages, there are two main groups designated M1 and M2. M1 macrophages: as mentioned earlier (previously referred to as classically activated macrophages), M1 "killer" macrophages are activated by LPS and IFN-gamma, and secrete high levels of IL-12 and low levels of IL-10. M1 macrophages have pro-inflammatory, bactericidal, and phagocytic functions.
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Silver proteinate (brand name: Protargol) is used in electron microscopy with periodic acid and thiocarbohydrazide or thiosemicarbohydrazide as a positive stain for carbohydrates such as glycogen. It can also be used for light microscopy to stain nerve tissue. It is normally available as 8% silver in combination with albumin.Silver proteinate at Sigma-Aldrich Because of its bactericidal properties it was used to treat gonorrhea before the discovery of antibiotics.
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Sanitation is also important. Workers and those handling the infected leaves should wash their hands and keep infected plant material from uninfected areas. These infected cuttings and seedlings should not be planted or kept near uninfected fields as the pathogen is able to survive on the host's seeds. The disease can be managed with copper or bactericidal products, but is not always successful in preventing disease spread when conditions are wet.
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Another theory states that chromosomal toxin-antitoxin systems are designed to be bacteriostatic rather than bactericidal. RelE, for example, is a global inhibitor of translation, is induced during nutrient stress. By shutting down translation under stress, it could reduce the chance of starvation by lowering the cell's nutrient requirements. However, it was shown that several toxin- antitoxin systems, including relBE, do not give any competitive advantage under any stress condition.
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Difloxacin is a bactericidal, broad-spectrum antibiotic that has activity against Gram-negative bacteria and Gram-positive bacteria. It exerts its antibacterial effect by interfering with the bacterial enzyme DNA gyrase, which is needed for the maintenance and synthesis of bacterial DNA. The minimum inhibitory concentrations (MICs) of pathogens isolated in clinical field trials conducted in the United States between 1991 and 1993 were determined using National Committee for Clinical Laboratory Standards (NCCLS).
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Like all beta-lactam antibiotics, ertapenem is bactericidal. It inhibits cross-linking of the peptidoglycan layer of bacterial cell walls by blocking a type of enzymes called penicillin-binding proteins (PBPs). When a bacterial cell tries to synthesize new cell wall in order to grow and divide, the attempt fails, rendering the cell vulnerable to osmotic disruption. Additionally, the surplus of peptidoglycan precursors triggers autolytic enzymes of the bacterium, which disintegrate the existing wall.
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Both innovations made it possible to produce a treatment that was cheap, seemingly effective, and could be distributed on a large scale. Scientists eventually realised that DDS was only weakly bactericidal against M. leprae, and it was considered necessary for patients to take the drug indefinitely. When dapsone was used alone, the M. leprae population quickly evolved antibiotic resistance. By the 1960s, the world's only known anti- leprosy drug became ineffective against resistant bacteria.
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Dalbavancin is a lipoglycopeptide belonging in the same glycopeptide class as vancomycin. Similar to other glycopeptides, dalbavancin exerts its bactericidal effect by disrupting cell wall biosynthesis. It binds to the D-alanyl-D-alanyl residue on growing peptidoglycan chains and prevents transpeptidation from occurring, preventing peptidoglycan elongation and cell wall formation. Dalbavancin also dimerizes and anchors itself in the lipophilic bacterial membrane, thereby increasing its stability in the target environment and its affinity for peptidoglycan.
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Due to their toxicity, use of glycopeptide antibiotics is restricted to patients who are critically ill, who have a demonstrated hypersensitivity to the β-lactams, or who are infected with β-lactam-resistant species. These antibiotics are effective principally against Gram-positive cocci. They exhibit a narrow spectrum of action, and are bactericidal only against the enterococci. Some tissues are not penetrated very well by glycopeptides, and they do not penetrate into the cerebrospinal fluid.
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Dihydrostreptomycin is a derivative of streptomycin that has a bactericidal properties. It is a semisynthetic aminoglycoside antibiotic used in the treatment of tuberculosis. It acts by irreversibly binding the S12 protein in the bacterial 30S ribosomal subunit, after being actively transported across the cell membrane, which interferes with the initiation complex between the mRNA and the bacterial ribosome. This leads to the synthesis of defective non- functional proteins, which results in the bacterial cell's death.
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The closer the MIC is to the MBC, the more bactericidal the compound. The first step in drug discovery is often the screening of a library drug candidate for MICs against bacteria of interest. As such, MICs are usually the starting point for larger pre- clinical evaluations of novel antimicrobial agents. The purpose of measuring the minimum inhibitory concentration is to ensure that antibiotics are chosen efficiently to increase the success of treatment.
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No systemic side effects have been identified. The safety of taurolidine has also been confirmed in clinical studies with long-term intravenous administration of high doses (up to 20 grams daily). In the body, taurolidine is metabolized rapidly via the metabolites taurultam and methylol taurinamide, which also have a bactericidal action, to taurine, an endogenous aminosulphonic acid, carbon dioxide and water. Therefore, no toxic effects are known or expected in the event of accidental injection.
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This syndrome also leads to neutropenia and phagocyte bactericidal dysfunction due to impaired chemotaxis. Deficiency in serotonin and adenosine-phosphate-containing granules in platelets causes impaired platelet aggregation, leading to prolonged bleeding time. Thus, patients are susceptible to infections and often present with oculo-cutaneous albinism and coagulation defects. Patients often present with early-onset aggressive periodontitis associated with advanced alveolar bone loss and tooth mobility due to neutropenia and defective neutrophil function.
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Milner Company had previously agreed to cease and desist several other false claims about germicidal and bactericidal properties of Pine-Sol in March 1951. In February 1963, the Dumas Milner Company, including Pine-Sol facilities in Jackson, MS and Perma-Starch plant in Illiopolis, IL, was taken over by Wayne, New Jersey based American Cyanamid for stock valued at $17 million. Howard S. Cohoon was to remain in charge of the division.
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The successful outcome of antimicrobial therapy with antibacterial compounds depends on several factors. These include host defense mechanisms, the location of infection, and the pharmacokinetic and pharmacodynamic properties of the antibacterial. A bactericidal activity of antibacterials may depend on the bacterial growth phase, and it often requires ongoing metabolic activity and division of bacterial cells. These findings are based on laboratory studies, and in clinical settings have also been shown to eliminate bacterial infection.
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An azurophilic granule is a cellular object readily stainable with a Romanowsky stain. In white blood cells and hyperchromatin, staining imparts a burgundy or merlot coloration. Neutrophils in particular are known for containing azurophils loaded with a wide variety of anti-microbial defensins that fuse with phagocytic vacuoles. Azurophils may contain myeloperoxidase, phospholipase A2, acid hydrolases, elastase, defensins, neutral serine proteases, bactericidal/permeability-increasing protein, lysozyme, cathepsin G, proteinase 3, and proteoglycans.
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With the ability to kill gram-positive and gram-negative bacteria, fungi, spirochetes and some enveloped viruses, cryptdins are classified as broad-spectrum antimicrobial peptides. Although it is the least expressed of the six isoforms, cryptdin-4 is the most bactericidal. Procryptdins, however, are nonbactericidal and thus require degradation of the proregion by MMP-7 for activation. In response to bacterial antigens, Paneth cells release their secretory granules into the lumen of intestinal crypts.
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It is also used as a mild laxative and has an anti- inflammatory and bactericidal effect . Research with animals suggests antispasmodic, anxiolytic, anti-inflammatory and some antimutagenic and cholesterol-lowering effects for chamomile. As well chamomile was found to be effective in treating stomach and intestinal cramps. The chamomile oil can be processed into pills, but the flower head can also be used as a whole to make use of the beneficial effect.
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The bactericidal action of Cefixime is due to the inhibition of cell wall synthesis. It binds to one of the penicillin binding proteins (PBPs) which inhibits the final transpeptidation step of the peptidoglycan synthesis in the bacterial cell wall, thus inhibiting biosynthesis and arresting cell wall assembly resulting in bacterial cell death. Absorption Only 40–50% is absorbed from the GI tract (oral bioavailability). Absorption may be decreased when taken with food.
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Quinolones and fluoroquinolones are bactericidal drugs, eradicating bacteria by interfering with DNA replication. Like other fluoroquinolones, enoxacin functions by inhibiting bacterial DNA gyrase and topoisomerase IV. The inhibition of these enzymes prevents bacterial DNA replication, transcription, repair and recombination. Recently, it was shown that Enoxacin inhibits the expression of the microRNA mir-34-5p, leading to an increase in the lifespan of the nematode C. elegans. Enoxacin is active against many Gram-positive bacteria.
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Antimicrobial resistance is a global threat that leads to an estimated 700,000 deaths annually with projections of 10M deaths per year and lost economic potential of $100T by 2050. The Unites States has released a national action plan to combat antibiotic resistant bacteria. Recombinant pGSN (rhu-pGSN) supplementation alone shows improved survival and decreased bacteria counts in several mouse models. The bactericidal activity of the antimicrobial peptide LL-37 was shown to be inhibited by F-actin.
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It formed bundles with F-actin in vitro that were dissolved by pGSN, restoring bactericidal activity. Bacteria growth was reduced when pGSN was added cystic fibrosis sputum, which is known to contain F-actin. When mice were given a penicillin-resistant strain of pneumococcal pneumonia, penicillin had no effect on mortality or morbidity. rhu-pGSN improved both mortality and morbidity on its own, and the combination of rhu-pGSN and penicillin gave further improvement of both suggesting possible synergism.
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Its mechanism of action is not thoroughly understood, but it is believed to be similar to the other fluoroquinolones by impairing the bacterial DNA gyrase which results in rapid bactericidal activity.Boothe, D.M. (2001) Antimicrobial drugs. In Small Animal ClinicalPharmacology and Therapeutics, pp. 150–173. W. B. Saunders Co.,Philadelphia, PA. The other proposed mechanisms include that it acts against nondividing bacteria and does not require protein and RNA synthesis, which block protein and RNA synthesis respectively.
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This process inhibits the synthesis of mycolic acids, which are required components of the mycobacterial cell wall. A range of radicals are produced by KatG activation of isoniazid, including nitric oxide, which has also been shown to be important in the action of another antimycobacterial prodrug pretomanid. 500px Isoniazid is bactericidal to rapidly dividing mycobacteria, but is bacteriostatic if the mycobacteria are slow-growing. It inhibits the cytochrome P450 system and hence acts as a source of free radicals.
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Like all Hygrophorus species, the fungus is mycorrhizal—a symbiotic association whereby the underground fungal mycelia penetrate and exchange nutrients with tree roots. They are common in a variety of forest types, where they grow on the ground in thickets or grassy areas. Hygrophorus eburneus is the type species of the genus Hygrophorus. A number of biologically active chemicals have been purified from the fruit bodies of the fungus, including fatty acids with bactericidal and fungicidal activity.
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HOCl is known to cause post-translational modifications to proteins, the notable ones being cysteine and methionine oxidation. A recent examination of HOCl's bactericidal role revealed it to be a potent inducer of protein aggregation. Hsp33, a chaperone known to be activated by oxidative heat stress, protects bacteria from the effects of HOCl by acting as a holdase, effectively preventing protein aggregation. Strains of Escherichia coli and Vibrio cholerae lacking Hsp33 were rendered especially sensitive to HOCl.
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Polyhexamethylene guanidine (PHMG) is a guanidine derivative that is used as a biocidal disinfectant, often in the form of its salt polyhexamethylene guanidine phosphate (PHMG-P). Studies have shown that PHMG in solution has fungicidal as well as bactericidal activity against both Gram-positive and Gram-negative bacteria. The substance also has detergent, anti-corrosive, and flocculant properties and prevents biofouling. PHMG-P is a white powdered solid, and as all polyguanidine salts, readily soluble in water.
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Clindamycin may be useful in skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Many strains of MRSA are still susceptible to clindamycin; however, in the United States spreading from the West Coast eastwards, MRSA is becoming increasingly resistant. While it has been used in intraabdominal infections, such use is generally not recommended due to resistance. Clindamycin is used in cases of suspected toxic shock syndrome, often in combination with a bactericidal agent such as vancomycin.
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The Ra-reactive factor (RARF) is a complement-dependent bactericidal factor that binds to the Ra and R2 polysaccharides expressed by certain enterobacteria. Alternate splicing of this gene results in two transcript variants encoding two RARF components that are involved in the mannan-binding lectin pathway of complement activation. The longer isoform is cleaved into two chains which form a heterodimer linked by a disulfide bond. The encoded proteins are members of the trypsin family of peptidases.
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Butylparaben is one of the most common bactericidal/fungicidal additives in cosmetics. It has been used in cosmetic products since the 1940s and in pharmaceutical products since 1924. The popularity of butylparaben in these products is due to its low toxicity in humans and its effective antimicrobial properties, in particular those against mold and yeast. It is now found in more than 20,000 cosmetic products including eye shadow, facial moisturizer/treatment, anti-aging cream, foundation, and sunscreen.
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In his book Biological Stains, Conn describes gentian violet as a "poorly defined mixture of violet rosanilins". The German ophthalmologist Jakob Stilling is credited with discovering the antiseptic properties of gentian violet. He published a monograph in 1890 on the bactericidal effects of a solution that he christened "pyoktanin", which was probably a mixture of aniline dyes similar to gentian violet. He set up a collaboration with E. Merck & Co. to market "Pyoktanin caeruleum" as an antiseptic.
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PZA is only weakly bactericidal, but is very effective against bacteria located in acidic environments, inside macrophages, or in areas of acute inflammation. All TB regimens in use were 18 months or longer until the appearance of rifampicin. In 1953, the standard UK regimen was 3SPH/15PH or 3SPH/15SH2. Between 1965 and 1970, EMB replaced PAS. RMP began to be used to treat TB in 1968 and the BTS study in the 1970s showed that 2HRE/7HR was efficacious.
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The arenicin family has shown to have bactericidal effects on a broad range of multi-drug resistant Gram- negative and Gram-positive bacteria in both in vitro and in vivo studies. Arenicin-3 is currently being developed as an antibiotic for hospital-acquired infections caused by Gram-negative bacteria. Hospital-acquired infections are being targeted due to their susceptibility to multi-drug resistance. In particular, Arenicin-3 is being tested for hospital-acquired pneumonia and hospital-acquired urinary tract infections.
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A cat with an Elizabethan collar Lick granuloma from excessive licking It has been long observed that the licking of their wounds by dogs might be beneficial. Indeed, a dog's saliva is bactericidal against the bacteria Escherichia coli and Streptococcus canis, although not against coagulase-positive Staphylococcus or Pseudomonas aeruginosa. Wound licking is also important in other animals. Removal of the salivary glands of mice and rats slows wound healing, and communal licking of wounds among rodents accelerates wound healing.
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Plantazolicin (PZN) is a natural antibiotic produced by the gram-positive soil bacterium Bacillus velezensis FZB42Proteomes - Bacillus velezensis (strain DSM 23117 / BGSC 10A6 / FZB42) (Bacillus amyloliquefaciens subsp. plantarum) (previously Bacillus amyloliquefaciens FZB42). PZN has specifically been identified as a selective bactericidal agent active against Bacillus anthracis, the causative agent of anthrax. This natural product is a ribosomally synthesized and post-translationally modified peptide (RiPP); it can be classified further as a thiazole/oxazole-modified microcin (TOMM) or a linear azole-containing peptide (LAP).
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The biguanide polymer polyaminopropyl biguanide is specifically bactericidal at very low concentrations (10 mg/l). It has a unique method of action: The polymer strands are incorporated into the bacterial cell wall, which disrupts the membrane and reduces its permeability, which has a lethal effect to bacteria. It is also known to bind to bacterial DNA, alter its transcription, and cause lethal DNA damage. It has very low toxicity to higher organisms such as human cells, which have more complex and protective membranes.
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It can be used as an active ingredient to relieve the pain of mouth ulcers and denture sores in buccal solutions or gels such as Pansoral or in Bonjela. The usual concentration in these products is 0.01% (w/w). However, it isn't known as a potent bactericidal compound, mainly because of its low solubility in water. For example, US and European pharmacopeias enforce suppliers of benzalkonium chloride to limit the amount of cetalkonium chloride in the mixture to less than 5% w/w.
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A study done by NEERI, a government of India funded research institution shows that the river Ganga is unique in its sediment content that is more radioactive compared to any other river and lake water sediments. These sediments release Copper and Chromium and have bactericidal properties that multiply coliphages reducing and ultimately eliminating coliforms from water. River activist and economist Dr. Bharat Jhunjhunwala has claimed that the dredging activities undertaken will destroy the self- purification capacity unique to the Ganga.
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Isoniazid was widely used in the treatment of Mycobacterium avium complex as part of a regimen including rifampicin and ethambutol. Evidence suggests that isoniazid prevents mycolic acid synthesis in M. avium complex as in M. tuberculosis and although this is not bactericidal to M. avium complex, it greatly potentiates the effect of rifampicin. The introduction of macrolides led to this use greatly decreasing. However, since rifampicin is broadly underdosed in M. avium complex treatment this effect may be worth re- investigating.
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Cephalosporins are a broad class of bactericidal antibiotics that include the β-lactam ring and share a structural similarity and mechanism of action with other β-lactam antibiotics (e.g. penicillins, carbapenems and monobactams). The cephalosporins (and other β-lactams) have the ability to kill bacteria by inhibiting essential steps in the bacterial cell wall synthesis which in the end results in osmotic lysis and death of the bacterial cell. Cephalosporins are widely used antibiotics because of their clinical efficiency and desirable safety profile.
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Post-treatment consists of preparing the water for distribution after filtration. Reverse osmosis is an effective barrier to pathogens, but post-treatment provides secondary protection against compromised membranes and downstream problems. Disinfection by means of ultraviolet (UV) lamps (sometimes called germicidal or bactericidal) may be employed to sterilize pathogens which bypassed the reverse-osmosis process. Chlorination or chloramination (chlorine and ammonia) protects against pathogens which may have lodged in the distribution system downstream, such as from new construction, backwash, compromised pipes, etc.
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CHS is a disease causing impaired bacteriolysis due to failure of phagolysosome formation. As a result of disordered intracellular trafficking there is impaired lysosome degranulation with phagosomes, so phagocytosed bacteria are not destroyed by the lysosome's enzymes. In addition, secretion of lytic secretory granules by cytotoxic T cells is affected. The disease is characterised by large lysosome vesicles in phagocytes (neutrophils), which thus have poor bactericidal function, leading to susceptibility to infections, abnormalities in nuclear structure of leukocytes, anemia, and hepatomegaly.
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He returned to Philadelphia College of Pharmacy where he became a professor of botany and pharmacognosy until 1917 in which year he moved to the University of Michigan before retiring after three years. He examined plant products in collaboration with the Michigan Botanical Gardens and ran correspondence courses. He served as the editor of the American Journal of Pharmacy from 1898 to 1917 in which he himself regularly published. One of his other interests was the role of metals as bactericidal agents.
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An illustration shows the different effects of the bacteriostatic agent and bactericidal agent A bacteriostatic agent or bacteriostat, abbreviated Bstatic, is a biological or chemical agent that stops bacteria from reproducing, while not necessarily killing them otherwise. Depending on their application, bacteriostatic antibiotics, disinfectants, antiseptics and preservatives can be distinguished. When bacteriostatic antimicrobials are used, the duration of therapy must be sufficient to allow host defense mechanisms to eradicate the bacteria. Upon removal of the bacteriostat, the bacteria usually start to grow again.
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C. acnes has many lytic enzymes that break down the proteins and lipids in the sebum, leading to an inflammatory response. The free-radical reaction of benzoyl peroxide can break down the keratin, therefore unblocking the drainage of sebum (comedolytic). It can cause nonspecific peroxidation of C. acnes, making it bactericidal, and it was thought to decrease sebum production, but disagreement exists within the literature on this. Some evidence suggests that benzoyl peroxide has an anti- inflammatory effect as well.
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Low O2 and high CO2 concentrations in packages are effective in limiting the growth of Gram negative bacteria, molds and aerobic microorganisms, such as Pseudomonas spp. High O2 combined with high CO2 could have bacteriostatic and bactericidal effects by suppression of aerobes by high CO2 and anaerobes by high O2. CO2 has the ability to penetrate bacterial membrane and affect intracellular pH. Therefore, lag phase and generation time of spoilage microorganisms are increased resulting in shelf life extension of refrigerated foods.
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Fosfomycin is bactericidal and inhibits bacterial cell wall biogenesis by inactivating the enzyme UDP-N- acetylglucosamine-3-enolpyruvyltransferase, also known as MurA. This enzyme catalyzes the committed step in peptidoglycan biosynthesis, namely the ligation of phosphoenolpyruvate (PEP) to the 3'-hydroxyl group of UDP-N- acetylglucosamine. This pyruvate moiety provides the linker that bridges the glycan and peptide portion of peptidoglycan. Fosfomycin is a PEP analog that inhibits MurA by alkylating an active site cysteine residue (Cys 115 in the Escherichia coli enzyme).
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A unique trait of Streptomyces antibioticus is its ability to produce several antibiotics of different classes. Upon its discovery, it was found that S. antibioticus produced a then novel substance named Actinomycin. This substance was then separated into two compounds: Actinomycin A and Actinomycin B. Actinomycin A was found to be highly bacteriostatic (bacteria hindering) against all bacteria it was tested with. Actinomycin B displayed little bacteriostatic activity but was shown to be highly bactericidal (bacteria killing), particularly towards gram-positive bacteria.
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Phagocytes possess a superoxide-producing NADPH oxidase enzyme complex. Other cells in the respiratory tract also produce superoxide and hydrogen peroxide through the activity of dual oxidase 2 proteins, also known as Duox2. The superoxide generated by these enzymes complexes dismutates into hydrogen peroxide which in turn is used by myeloperoxidase to produce bactericidal hypochlorous acid. In addition, the submucosal glands of the respiratory tract secrete myeloperoxidase and lactoperoxidase (LPO) that catalyzes the oxidation of thiocyanate and detoxify hydrogen peroxide or ROS to the antimicrobial hypothiocyanite.
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Standard treatment in high-risk cases is azithromycin, a macrolide antibiotic, especially for Campylobacter infections in children, although other antibiotics, such as quinolones, tetracycline and other macrolides are sometimes used to treat gastrointestinal Campylobacter infections in adults. In case of systemic infection, other bactericidal antibiotics are used, such as ampicillin, amoxicillin/clavulanic acid, or aminoglycosides. Fluoroquinolone antibiotics, such as ciprofloxacin or levofloxacin, may no longer be effective in some cases, due to resistance. In addition to antibiotics, dehydrated children may require intravenous fluid treatment in a hospital.
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X-ray treatment of tuberculosis in 1910 X-rays and radium were noted by physicians to have different advantages in different cases. The most marked effects produced with radium therapy were with lupus, ulcerous growths, and keloid, particularly because they could be applied more specifically to tissues than with x-rays. Radium was generally to be preferred when a localized reaction was desired, while for x-rays when a large area needed to be treated. Radium was also believed to be bactericidal, while x-rays were not.
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Cedarwood essential oil Cedar oil, also known as cedarwood oil, is an essential oil derived from various types of conifers, most in the pine or cypress botanical families. It is produced from the foliage, and sometimes the wood, roots, and stumps which have been left after cutting of trees for timber extraction. It has many uses in medicine, art, industry and perfumery, and while the characteristics of oils derived from various species may themselves vary, all have some degree of bactericidal and pesticidal effects.
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Pretomanid was first identified in 2000, in a series of 100 nitroimidazopyran derivatives synthesized and tested for antitubercular activity, by PathoGenesis (now a subsidiary of Novartis). Importantly, pretomanid has activity against static M. tuberculosis isolates that survive under anaerobic conditions, with bactericidal activity comparable to that of the existing drug metronidazole. Pretomanid requires metabolic activation by Mycobacterium for antibacterial activity. Pretomanid was not the most potent compound in the series against cultures of M. tuberculosis, but it was the most active in infected mice after oral administration.
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Cefalexin is a beta-lactam antibiotic of the cephalosporin family. It is bactericidal and acts by inhibiting synthesis of the peptidoglycan layer of the bacterial cell wall. As cefalexin closely resembles d-alanyl-d-alanine, an amino acid ending on the peptidoglycan layer of the cell wall, it is able to irreversibly bind to the active site of PBP, which is essential for the synthesis of the cell wall. It is most active against gram-positive cocci, and has moderate activity against some gram-negative bacilli.
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Anethole has potent antimicrobial properties, against bacteria, yeasts, and fungi. Reported antibacterial properties include both bacteriostatic and bactericidal action against Salmonella enterica but not when used against Salmonella via a fumigation method. Antifungal activity includes increasing the effectiveness of some other phytochemicals (such as polygodial) against Saccharomyces cerevisiae and Candida albicans; In vitro, anethole has antihelmintic action on eggs and larvae of the sheep gastrointestinal nematode Haemonchus contortus. Anethole also has nematicidal activity against the plant nematode Meloidogyne javanica in vitro and in pots of cucumber seedlings.
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The bactericidal properties of brass have been observed for centuries, particularly in marine environments where it prevents biofouling. Depending upon the type and concentration of pathogens and the medium they are in, brass kills these microorganisms within a few minutes to hours of contact. A large number of independent studies confirm this antimicrobial effect, even against antibiotic-resistant bacteria such as MRSA and VRSA. The mechanisms of antimicrobial action by copper and its alloys, including brass, are a subject of intense and ongoing investigation.
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Ethanol is used in medical wipes and most commonly in antibacterial hand sanitizer gels as an antiseptic for its bactericidal and anti-fungal effects. Ethanol kills microorganisms by dissolving their membrane lipid bilayer and denaturing their proteins, and is effective against most bacteria and fungi and viruses. However, it is ineffective against bacterial spores, but that can be alleviated by using hydrogen peroxide. A solution of 70% ethanol is more effective than pure ethanol because ethanol relies on water molecules for optimal antimicrobial activity.
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Penicillin and most other β-lactam antibiotics act by inhibiting penicillin- binding proteins, which normally catalyze cross-linking of bacterial cell walls. β-lactam antibiotics are bactericidal, and act by inhibiting the synthesis of the peptidoglycan layer of bacterial cell walls. The peptidoglycan layer is important for cell wall structural integrity, especially in Gram-positive organisms, being the outermost and primary component of the wall. The final transpeptidation step in the synthesis of the peptidoglycan is facilitated by DD-transpeptidases, also known as penicillin binding proteins (PBPs).
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This is supporting the endosymbiotic theory and indicates an evolution of plastid division in land plants. Under normal circumstances, peptidoglycan precursors signal a reorganisation of the bacterial cell wall and, as a consequence, trigger the activation of autolytic cell wall hydrolases. Inhibition of cross-linkage by β-lactams causes a build-up of peptidoglycan precursors, which triggers the digestion of existing peptidoglycan by autolytic hydrolases without the production of new peptidoglycan. As a result, the bactericidal action of β-lactam antibiotics is further enhanced.
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The main emphasis of Dr. Kristmundsdóttir´s research focused on the development and evaluation of pharmaceutical forms containing bactericidal fatty acids and monoglyceride, active ingredients in preventing infections through membranes and for treating skin and membrane infections. The results of her research demonstrated: 1) the advantages of using lipids in treating skin infections, and 2) that the membranes as the microbicidal lipids with which she has worked neither cause irritation nor allergies and do not provoke the body’s natural defences.Morgunblaðið. (1999, June 30). Ný aðferð drepur kynsjúkdómavalda.
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Xenon is used in light-emitting devices called xenon flash lamps, used in photographic flashes and stroboscopic lamps; to excite the active medium in lasers which then generate coherent light; and, occasionally, in bactericidal lamps. The first solid- state laser, invented in 1960, was pumped by a xenon flash lamp, and lasers used to power inertial confinement fusion are also pumped by xenon flash lamps. alt=Elongated glass sphere with two metal rod electrodes inside, facing each other. One electrode is blunt and another is sharpened.
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As a multimer, alpha-lactalbumin strongly binds calcium and zinc ions and may possess bactericidal or antitumor activity. A folding variant of human alpha-lactalbumin that may form in acidic environments such as the stomach, called HAMLET, probably induces apoptosis in tumor and immature cells. The corresponding folding dynamics of alpha- lactalbumin is thus highly unusual. When formed into a complex with Gal-T1, a galactosyltransferase, α-lactalbumin, enhances the enzyme's affinity for glucose by about 1000 times, and inhibits the ability to polymerise multiple galactose units.
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Together with bactericidal permeability-increasing protein (BPI), the encoded protein binds LPS and interacts with the CD14 receptor, probably playing a role in regulating LPS-dependent monocyte responses. Studies in mice suggest that the encoded protein is necessary for the rapid acute-phase response to LPS but not for the clearance of LPS from circulation. This protein is part of a family of structurally and functionally related proteins, including BPI, plasma cholesteryl ester transfer protein (CETP), and phospholipid transfer protein (PLTP). Finally, this gene is found on chromosome 20, immediately downstream of the BPI gene.
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Unlike copper alloys, stainless steel (S30400) does not exhibit any degree of bactericidal properties against E. coli O157:H7. This material, which is one of the most common touch surface materials in the healthcare industry, allows toxic E. coli O157:H7 to remain viable for weeks. Near-zero bacterial counts are not observed even after 28 days of investigation. Epifluorescence photographs have demonstrated that E. coli O157:H7 is almost completely killed on copper alloy C10200 after just 90 minutes at 20 °C; whereas a substantial number of pathogens remain on stainless steel S30400.
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The Phenol coefficient, is now largely of historical interest, although the principles upon which it is based are still used. It is a measure of the bactericidal activity of a chemical compound in relation to phenol. When listed numerically, the figure expressing the disinfecting power of a substance by relating it to the disinfecting power of phenol may be a function of the standardized test performed. For example, the Rideal–Walker method, introduced in 1903 gives a Rideal–Walker coefficient and the U.S. Department of Agriculture method gives a U.S. Department of Agriculture coefficient.
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A team led by Elena Ivanova at Swinburne University of Technology in Melbourne discovered in 2012 that cicada wings were potent killers of Pseudomonas aeruginosa, an opportunist germ that also infects humans and is becoming resistant to antibiotics. The effect came from regularly-spaced "nanopillars" on which bacteria were sliced to shreds as they settled on the surface. Both cicada wings and black silicon were put through their paces in a lab, and both were bactericidal. Smooth to human touch, the surfaces destroyed Gram-negative and Gram-positive bacteria, as well as bacterial spores.
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Scientists at the Italian drug company Achifar discovered rifabutin in 1975. (Eventually Archifar became part of Farmitalia Carlo Erba, a unit of the conglomerate Montedison which was subsequently bought by Pharmacia) This company's Adria Laboratories subsidiary filed for Food and Drug Administration (FDA) approval of rifabutin under the brand name Mycobutin in the early 1990s and the drug gained FDA approval in December 1992. Rifabutin is primarily bactericidal antibiotic drug used to treat tuberculosis. Its effect on bacteria is based on the DNA-dependent RNA polymerase blocking drug rifamycin S, a semi-synthetic derivative.
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The PGLYRP1 protein plays an important role in the innate immune response. It is bactericidal against gram-positive bacteria such as S. aureus, S. epidermidis, and L. monocytogenes and generally has proinflammatory effects, inducing TNF-a and IFN-g in many tissues. PGLYRP-1 is also known to form a cytotoxic complex with HSP-70, suggesting it may also have a role in anti-cancer defense. As a pathogen recognition protein with antimicrobial properties, PGLYRP-1 is suspected to play an important role in maintaining the gut microbial flora.
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Fidaxomicin, sold under the brand name Dificid among others, is the first member of a class of narrow spectrum macrocyclic antibiotic drugs called tiacumicins. It is a fermentation product obtained from the actinomycete Dactylosporangium aurantiacum subspecies hamdenesis. Fidaxomicin is minimally absorbed into the bloodstream when taken orally, is bactericidal, and selectively eradicates pathogenic Clostridium difficile with relatively little disruption to the multiple species of bacteria that make up the normal, healthy intestinal flora. The maintenance of normal physiological conditions in the colon may reduce the probability of recurrence of Clostridium difficile infection.
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Lysozyme PEGylation is the covalent attachment of Polyethylene glycol (PEG) to Lysozyme, which is one of the most widely investigated PEGylated proteins. The PEGylation of proteins has become a common practice of modern therapeutic drugs, as the process is capable of enhancing solubility, thermal stability, enzymatic degradation resistance, and serum half-life of the proteins of interest. Lysozyme, as a natural bactericidal enzyme, lyses the cell wall of various gram-positive bacteria and offers protection against microbial infections. Lysozyme has six lysine residues which are accessible for PEGylation reactions.
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Competence in S. pneumoniae is induced by DNA-damaging agents such as mitomycin C, fluoroquinolone antibiotics (norfloxacin, levofloxacin and moxifloxacin), and topoisomerase inhibitors. Transformation protects S. pneumoniae against the bactericidal effect of mitomycin C. Michod et al. summarized evidence that induction of competence in S. pneumoniae is associated with increased resistance to oxidative stress and increased expression of the RecA protein, a key component of the recombinational repair machinery for removing DNA damages. On the basis of these findings, they suggested that transformation is an adaptation for repairing oxidative DNA damages.
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Cefodizime is a 3rd generation cephalosporin antibiotic with broad spectrum activity against aerobic gram positive and gram negative bacteria. Clinically, it has been shown to be effective against upper and lower respiratory tract infections, urinary tract infections, and gonorrhea. Cefodizime is a bactericidal antibiotic that targets penicillin-binding proteins (PBPs) 1A/B, 2, and 3 resulting in the eventual death of the bacterial cell. In vivo experimental models of infection showed that bacterial clearance by this drug is at least as effective compared with other 3rd generation cephalosporins.
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The term also used to be restricted to antibacterials (and is often used as a synonym for them by medical professionals and in medical literature), but its context has broadened to include all antimicrobials. Antibacterial agents can be further subdivided into bactericidal agents, which kill bacteria, and bacteriostatic agents, which slow down or stall bacterial growth. In response, further advancements in antimicrobial technologies have resulted in solutions that can go beyond simply inhibiting microbial growth. Instead, certain types of porous media have been developed to kill microbes on contact.
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Calcium hydroxide Ca(OH)2 is conventionally used as a pulpotomy agent of the permanent teeth but with less long term success. Calcium hydroxide is a highly alkaline (pH 12) material that has bactericidal effect and has the potential to enhance reparative dentin (dentin bridge) formation. However, it also leads to superficial necrosis of the pulp tissue in contact with the medication and has been shown to be toxic to cells in tissue culture. Therefore, in spite being a popular vital pulp therapy material, its use as a pulpotomy agent remains controversial.
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In the presence of light, phloxine B has a bactericidal effect on gram-positive strains, such as Bacillus subtilis, Bacillus cereus, and several methicillin-resistant Staphylococcus aureus (MRSA) strains. At a minimum inhibitory concentration of 25 μM, growth is reduced by 10-fold within 2.5 hours. At concentrations of 50 μM and 100 μM, growth is stopped completely and cell counts decrease by a factor of 104 to 105. For humans, the Food and Drug Administration deems phloxine B to be safe up to a daily dosage of 1.25 mg/kg.
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However, if the infection does not respond to either of these, the medication is usually changed to tetracycline. If the infection is serious, then a bactericidal medication may be coupled with the antibiotics If a cat is carrying Bartonella henselae, then it may not exhibit any symptoms. Cats may be bacteremic for weeks to years, but infection is more common in young cats. Transmission to humans is thought to occur via flea feces inoculated into a cat scratch or bite, and transmission between cats occurs only in the presence of fleas.
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However, the combination of both substances acts synergistically and leads to a potent bactericidal activity that can reach up to 100 times that of the separate components. The pristinamycin biosynthetic gene cluster is the largest antibiotic supercluster known so far, with a size of ~210 kb, wherein the PI and PII biosynthetic genes are not clustered individually but are scattered across the complete sequence region.Mast Y, Weber T, Gölz M, Ort- Winklbauer R, Gondran A, Wohlleben W, Schinko E (2010) Characterization of the ‘pristinamycin supercluster’ of Streptomyces pristinaespiralis. Microbial Biotechnology.
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These features protect wild-type strains from antibodies and other chemical attacks, but require a large expenditure of energy and material resources. E. coli is often used as a representative microorganism in the research of novel water treatment and sterilisation methods, including photocatalysis. By standard plate count methods, following sequential dilutions, and growth on agar gel plates, the concentration of viable organisms or CFUs (Colony Forming Units), in a known volume of treated water can be evaluated, allowing the comparative assessment of materials performance.TiO2 coatings as bactericidal photocatalysts in water treatment.
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The T. pallidum strain 14 has built resistance to some macrolides, including erythromycin and azithromycin. Resistance to macrolides in T. Pallidum strain 14 is believed to derive from a single point mutation that increased the organism's livability. Many of the syphilis treatment therapies only lead to bacteriostatic results, unless larger concentrations of penicillin are used for bactericidal effects. Penicillin overall is the most recommended antibiotic by the CDC as it shows the best results with prolonged usage, it can inhibit and may even kill T. Pallidum at low to high doses with each increase in concentration being more effective.
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Like other fluoroquinolones, Prulifloxacin prevents bacterial DNA replication, transcription, repair and recombination through inhibition of bacterial DNA gyrase. Quinolones and fluoroquinolones are bactericidal drugs, eradicating bacteria by interfering with DNA replication. Quinolones are synthetic agents that have a broad spectrum of antimicrobial activity as well as a unique mechanism of action, resulting in inhibition of bacterial DNA gyrase and topoisomerase IV. Quinolones inhibit the bacterial DNA gyrase or the topoisomerase IV enzyme, thereby inhibiting DNA replication and transcription. For many gram-negative bacteria, DNA gyrase is the target, whereas topoisomerase IV is the target for many gram-positive bacteria.
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Ostrer graduated in 1972 from the Massachusetts Institute of Technology (Physics, Course 8). While an undergraduate student, he worked in the laboratory of Salvador Luria, studying the effects of the bactericidal agent, Colicin K. He received his M.D. degree from the Columbia University College of Physicians and Surgeons in 1976. While at Columbia, he established a community-based genetic screening program that was a pivotal influence for his subsequent career choice of medical genetics. He trained in pediatrics and medical genetics at Johns Hopkins University and in molecular genetics at the National Institutes of Health (NIH).
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The antibiotic susceptibility was determined using a single strain of M. pusilla with the purpose to produce axenic cultures to be used in studies and experiments. The strain of M.pusilla was tested with a range of antibiotics to determine the possible effects of the particular antibiotic. Resistance: benzylpenicillin, gentamicin, kanamycin, neomycin, streptomycin Sensitive: chloramphenicol, polymyxin B For M. pusilla, sensitivity towards an antibiotic is likely defined by the impairment of growth, rather than a lethal effect, when subjected to bactericidal levels of that particular antibiotic. The susceptibility of other strains of M. pusilla towards this set of antibiotics should be the same.
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S. griseus was first described in 1914 by Krainsky, who called the species Actinomyces griseus. The name was changed in 1948 by Waksman and Henrici to Streptomyces griseus. The interest in these strains stems from their ability to produce streptomycin, a compound which demonstrated significant bactericidal activity against organisms such as Yersinia pestis (the causative agent of plague) and Mycobacterium tuberculosis (the causative agent of tuberculosis). Streptomycin was discovered in the laboratory of Selman Waksman, although his PhD student Albert Schatz probably did most of the work on these strains of bacteria and the antibiotic they produce.
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He extended his tests using tears, which were contributed by his co-workers. As Allison reminisced, saying, "For the next five or six weeks, our tears were the source of supply for this extraordinary phenomenon. Many were the lemons we used (after the failure of onions) to produce a flow of tears... The demand by us for tears was so great, that laboratory attendants were pressed into service, receiving threepence for each contribution." His further tests with sputum, cartilage, blood, semen, ovarian cyst fluid, pus, and egg white showed that the bactericidal agent was present in all of these.
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As hemostasis is a basic function of thrombocytes in mammals, it also has its uses in possible infection confinement. In case of injury, platelets, together with the coagulation cascade, form the first line of defense by forming a blood clot. Thus, hemostasis and host defense were intertwined in evolution. For example, in the Atlantic horseshoe crab (living fossil estimated to be over 400 million years old), the only blood cell type, the amebocyte, facilitates both the hemostatic function and the encapsulation and phagocytosis of pathogens by means of exocytosis of intracellular granules containing bactericidal defense molecules.
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It is a general trend that adding a lipid group of a certain length (typically C10–C12) to a lipopeptide will increase its bactericidal activity. Lipopeptides with a higher amount of carbon atoms, for example 14 or 16, in its lipid tail will typically have antibacterial activity as well as anti-fugal activity. Lipopeptide detergents (LPDs) are composed of amphiphiles and two alkyl chains which are located on the last part of the peptide backbone. They were designed to mimic the architecture of the native membranes in which two alkyl chains in a lipid molecule facially interact with the hydrophobic segment of MPs.
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Thus, during the microbial eliminating process, there is no deterioration in chelated platinum ion content, such that the bactericidal effective can be continued and sustainable. Besides the effect surface energy, it is also speculated that the antimicrobial and antiviral properties of platinum would involve the following aspects. Same as other antimicrobial and antiviral metal ions, such as silver, gold, and copper platinum ion is also positively charged. Based on the chemical characteristics, the surface of either Gram- positive and Gram-negative bacteria is negatively charged Meanwhile, similar surface characteristics could be found in fungi and enveloped virus.
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Collins and collaborators have created genetic toggle switches, RNA switches, genetic counters, programmable cells, tunable mammalian genetic switches, and engineered bacteriophage, each with broad applications in biotechnology and biomedicine. Collins is also one of the leading researchers in systems biology, pioneering the use of experimental-computational biophysical techniques to reverse engineer and analyze endogenous gene regulatory networks. Collins and collaborators showed that reverse-engineered gene networks can be used to identify drug targets, biological mediators and disease biomarkers. Collins and collaborators discovered, using systems biology approaches, that all classes of bactericidal antibiotics induce a common oxidative damage cellular death pathway.
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As the mandelic acid salt (generic methenamine mandelate, USP) it is used for the treatment of urinary tract infection. It decomposes at an acidic pH to form formaldehyde and ammonia, and the formaldehyde is bactericidal; the mandelic acid adds to this effect. Urinary acidity is typically ensured by co-administering vitamin C (ascorbic acid) or ammonium chloride. Its use had temporarily been reduced in the late 1990s, due to adverse effects, particularly chemically-induced hemorrhagic cystitis in overdose, but its use has now been re-approved because of the prevalence of antibiotic resistance to more commonly used drugs.
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The MBC is identified by determining the lowest concentration of antibacterial agent that reduces the viability of the initial bacterial inoculum by ≥99.9%. The MBC is complementary to the MIC; whereas the MIC test demonstrates the lowest level of antimicrobial agent that inhibits growth, the MBC demonstrates the lowest level of antimicrobial agent that results in microbial death. This means that even if a particular MIC shows inhibition, plating the bacteria onto agar might still result in organism proliferation because the antimicrobial did not cause death. Antibacterial agents are usually regarded as bactericidal if the MBC is no more than four times the MIC.
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At the academy, he worked on many projects, such as the study of the relationship of tuberculosis in humans and farm animals in Siberia, the use of intravenousTranslation of Russian article in the scientific journal "Sovetskaya Meditsina" April 4, 1979 IV intermittent chemotherapy in rural areas bactericidal anti-tuberculosis therapy, and the use of artificial pneumothorax and pneumoperitoneum to cure tuberculosis. Ursov is the author of more than 210 published scientific articles with 10 monographs among them. He guided and prepared thirty candidates of medicine and eight Doctors of Medical Sciences. Ursov developed the traditional Russian tuberculosis school as the head of the Tuberculosis Department of Novosibirsk Medical University.
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Clorox brand bleach Bleach is the generic name for any chemical product which is used industrially and domestically to remove color from a fabric or fiber or to clean or to remove stains in a process called bleaching. It often refers, specifically, to a dilute solution of sodium hypochlorite, also called "liquid bleach". Many bleaches have broad spectrum bactericidal properties, making them useful for disinfecting and sterilizing and are used in swimming pool sanitation to control bacteria, viruses, and algae and in many places where sterile conditions are required. They are also used in many industrial processes, notably in the bleaching of wood pulp.
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Copper zinc water filtration is a high-purity brass water filtration process that relies on the redox potential of dissolved oxygen in water in the presence of a zinc anode and copper cathode. It uses dissolved impurities within water as constituent substrate, which are reduced to more physiologically inert compounds. Due to inherent limitations in bactericidal and antiprotozoal activity and poor filtration of organic chemicals (in particular organophosphate pesticides), copper zinc water filters are not commonly used in the household setting unless combined with carbon based systems. They also have application in the industrial setting to extend the life of carbon based filtration systems for waste water effluent.
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Quorum sensing, a process which allows for differential gene expression in response to changes in cell density, can trigger bacterial biofilm formation when bacteria are present in sufficiently high concentrations. Biofilm formation in turn drives resistance to a range of environmental and biological stressors, including antibiotics and human immune responses, and the 2(5H)-furanone-mediated disruption of quorum sensing has been shown to negatively impact the growth rate of Campylobacter jejuni, a clinically significant food-borne pathogen. 2(5H)-furanone derivatives have also demonstrated in vitro bactericidal effects against Mycobacterium tuberculosis and Methicillin-resistant Staphylococcus aureus, two species that have demonstrated increased resistance to more traditional antibiotics.
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While studies conducted up until the 1960s found little evidence supporting antibacterial activity for cerumen, more recent studies have found that cerumen has a bactericidal effect on some strains of bacteria. Cerumen has been found to reduce the viability of a wide range of bacteria, including Haemophilus influenzae, Staphylococcus aureus, and many variants of Escherichia coli, sometimes by as much as 99%. The growth of two fungi commonly present in otomycosis was also significantly inhibited by human cerumen. These antimicrobial properties are due principally to the presence of saturated fatty acids, lysozyme and, especially, to the slight acidity of cerumen (pH typically around 6.1 in normal individuals).
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Cefotaxime drug information Due to the mechanism of their attack on bacterial cell wall synthesis, β-lactams are considered to be bactericidal. Unlike β-lactams such as penicillin and amoxicillin, which are highly susceptible to degradation by β-lactamase enzymes (produced, for example, nearly universally by S. aureus), cefotaxime boasts the additional benefit of resistance to β-lactamase degradation due to the structural configuration of the cefotaxime molecule. The syn-configuration of the methoxyimino moiety confers stability against β-lactamases. Consequently, the spectrum of activity is broadened to include several β-lactamase-producing organisms (which would otherwise be resistant to β-lactam antibiotics), as outlined below.
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Neuronal expression of the mammalian autophagy promoting protein Beclin 1 protects mice against lethal Sindbis virus encephalitis " though the general importance of xenophagy is not yet certain.John P. Greer, John Foerster, George M. Rodgers Wintrobe's Clinical Hematology Volume 2 - Page 271 2008 "The general importance of xenophagy is not yet certain. Among the key components that are transferred to the phagosome and are critical in creating an antimicrobial environment are the vacuole ATPase, NOS2, and phagocyte oxidase ..."Issues in Biological, Biochemical, and Evolutionary Sciences "We also find that the invasive efficiency of group A Streptococcus into cells is not altered by knockdown of VAMP8 or Vti1b, whereas cellular bactericidal efficiency is significantly diminished, indicating that xenophagy is functionally impaired.
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A bottle of glycerin purchased at a pharmacy Personal lubricants commonly contain glycerol Glycerol is an ingredient in products such as hair gel Glycerol suppositories used as laxatives Glycerin is mildly antimicrobial and antiviral and is an FDA approved treatment for wounds. The Red Cross reports that an 85% solution of glycerin shows bactericidal and antiviral effects, and wounds treated with glycerin show reduced inflammation after roughly 2 hours. Due to this it is used widely in wound care products, including glycerin based hydrogel sheets for burns and other wound care. It is approved for all types of wound care except third degree burns, and is used to package donor skin used in skin grafts.
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Streptomycin in complex with a bacterial ribosome. X-ray crystallographic structure of the 30S ribosomal subunit with bound drug (purple, space-filling model, at center) protein secondary structure elements such as alpha-helices in bright green, and the RNA phosphodiester backbone shown in orange (and the ladder of base pairs in dark green and blue) Aminoglycosides display concentration-dependent bactericidal activity against "most gram-negative aerobic and facultative anaerobic bacilli" but not against gram-negative anaerobes and most gram- positive bacteria. They require only short contact time, and are most effective against susceptible bacterial populations that are rapidly multiplying.DVM Boothe, DVM, PhD, 2012, Aminoglycosides (Aminocyclitols), The Merck Veterinary Manual , accessed 22 February 2014.
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The United States Environmental Protection Agency found that copper zinc water filtration can remove mercury from contaminated water, but only at low concentrations, and recommends that for highly contaminated water other processes be used. Due to their bactericidal action, copper zinc water filtration devices are considered by the EPA to be "pesticidal". However, Stanford physician Paul Auerbach recommends against their usage as a sole means of germicidal water treatment, and he does not include them amongst his recommended protozoal disinfection methods at either point of entry or point of use. A 1995 United States Environmental Protection Agency report found that such systems were employed at approximately 20 US-based cooling towers in 1993.
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Classically, two types of effector CD4+ T helper cell responses can be induced by a professional APC, designated Th1 and Th2, each designed to eliminate different types of pathogens. The factors that dictate whether an infection triggers a Th1 or Th2 type response are not fully understood, but the response generated does play an important role in the clearance of different pathogens. The Th1 response is characterized by the production of Interferon-gamma, which activates the bactericidal activities of macrophages, and induces B cells to make opsonizing (marking for phagocytosis) and complement-fixing antibodies, and leads to cell-mediated immunity. In general, Th1 responses are more effective against intracellular pathogens (viruses and bacteria that are inside host cells).
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Generally, it is not a simple process to turn an inert precious metal directly into its water-soluble ionic state. Material under high energy treatment would gain certain amount of energy according to energy storage effect. Therefore, when inert metal directly turns into its ionic water-soluble state under high energy treatment, it is certain that this aqueous solution would possess large amount of energy. Due to the high energy state and dielectric properties of platinum metal ion in chelated state, the energy conversion at the contact point between platinum ion and bacteria, which is similar to the situation of electrical short circuit, would lead to cell burst and trigger bactericidal effect.
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In contrast to the ysc and yop genes listed above, the Yops that act directly on host cells to cause cytopathologic effects – "effector Yops" – are encoded by pYV genes external to this core region. The sole exception is LcrV, which is also known as the "versatile Yop" for its two roles as an effector Yop and as a regulatory Yop. The combined function of these effector Yops permits the bacteria to resist internalization by immune and intestinal cells and to evade the bactericidal actions of neutrophils and macrophages. Inside the bacterium, these Yops are bound by pYV-encoded Sycs (specific Yop chaperones), which prevent premature interaction with other proteins and guide the Yops to a type-III secretory apparatus.
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ECSIT has been found to play multiple roles in cell-signaling, including those that utilize Toll-like receptors (TLRs), TGF-β, and BMP. ECSIT plays a regulatory role as part of the TAK1-ECSIT-TRAF6 complex that is involved in the activation of NF-κB by the TLR4 signal and through its interactions with TRIM59 to negatively regulate NF-κB, IRF-3, and IRF-7-mediated signal pathways. Additionally, ECSIT appears to contribute to bactericidal activity in TLR signaling through its interaction with tumor necrosis factor receptor-associated factor 6 (TRAF6). Importantly, ubiquitination of ECSIT has shown itself to be necessary for the activation of p65/p50 NF-κBs in TLR4 signaling.
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JHBP protects the JH molecules from hydrolysis by non-specific esterases present in the insect haemolymph. The crystal structure of the JHBP from Galleria mellonella (greater wax moth) shows an unusual fold consisting of a long alpha-helix wrapped in a much curved antiparallel beta-sheet. The folding pattern for this structure closely resembles that found in some tandem-repeat mammalian lipid- binding and bactericidal permeability-increasing proteins, with a similar organisation of the major cavity and a disulfide bond linking the long helix and the beta-sheet. It would appear that JHBP forms two cavities, only one of which, the one near the N- and C-termini, binds the hormone; binding induces a conformational change, of unknown significance.
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After his notional retirement in 1985, he continued working first at the Royal Postgraduate Medical School, Hammersmith and then at St George's, University of London. He developed the technique of measuring the early bactericidal activity of drugs, which is now standard practice as the initial step in the phase II of clinical development of new drugs with Amina Jindani and colleagues in South Africa. He also introduced the concept of the 8-week phase II study with the proportion of patients obtaining negative sputum culture at 8 weeks, a standard assessment in most such studies. More recently he developed a new type of phase II 8-week study using modelling of counts of TB in sputum during treatment (with Geraint Davies and the South African MRC).
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In 2004, the University of Southampton research team was the first to clearly demonstrate that copper inhibits MRSA.Noyce, J. O. and Keevil, C. W. (2004), The Antimicrobial Effects of Copper and Copper-Based Alloys on Methicillin-resistant Staphylococcus aureus, Copper Development Association Poster Q-193 from Proceedings of the Annual General Meeting of the American Society for Microbiology, 24–27 May 2004, New Orleans; presented at the American Society for Microbiology General Meeting, New Orleans, Louisiana May 24 On copper alloys — C19700 (99% copper), C24000 (80% copper), and C77000 (55% copper) — significant reductions in viability were achieved at room temperatures after 1.5 hours, 3.0 hours, and 4.5 hours, respectively. Faster antimicrobial efficacies were associated with higher copper alloy content. Stainless steel did not exhibit any bactericidal benefits.
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Gentamicin is a bactericidal antibiotic that works by binding the 30S subunit of the bacterial ribosome, negatively impacting protein synthesis. The primary mechanism of action is generally accepted to work through ablating the ability of the ribosome to discriminate on proper transfer RNA and messenger RNA interactions. Typically, if an incorrect tRNA pairs with an mRNA codon at the aminoacyl site of the ribosome, adenosines 1492 and 1493 are excluded from the interaction and retract, signaling the ribosome to reject the aminoacylated tRNA::Elongation Factor Thermo-Unstable complex. However, when gentamicin binds at helix 44 of the 16S rRNA, it forces the adenosines to maintain the position they take when there is a correct, or cognate, match between aa-tRNA and mRNA.
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The synthesis of 4-hydroxyquinolines and 4-quinolones is of great importance to a variety of fields, but most notably to the medical sciences due to their use as chemotherapeutic bactericidal drugs through their ability to kill bacteria. This mechanism involved disabling the bacterial topoisomerase II/IV enzyme (the target in most Gram-positive bacteria) or DNA gyrase (the target in Gram-negative bacteria), preventing the bacteria from unwinding their DNA and undergoing either DNA replication or transcription. The majority of drugs in clinical use are actually quinoline derivatives that belong to the subset fluoroquinolones, which have a fluorine atom attached to the central ring system, often at the C-6 or C-7 position. There are also many non-antibacterial medical uses for 4-hydroxyquinoline.
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Results have been graded into susceptible (often called sensitive), intermediate, or resistant to a particular antimicrobial by using a breakpoint. Breakpoints are agreed upon values, published in guidelines of a reference body, such as the U.S. Clinical and Laboratory Standards Institute (CLSI), the British Society for Antimicrobial Chemotherapy (BSAC) or the European Committee on Antimicrobial Susceptibility Testing (EUCAST). There have been major discrepancies between the breakpoints from various European countries over the years, and between those from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the US Clinical and Laboratory Standards Institute (CLSI). While MIC is the lowest concentration of an antibacterial agent necessary to inhibit visible growth, minimum bactericidal concentration (MBC) is the minimum concentration of an antibacterial agent that results in bacterial death.
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Salmonella. Chakravortty's research focus is on antibacterial resistance with special emphasis on Salmonella and she is known to have done work on the pathogenesis of Salmonella typhimurium, a gram negative bacterium pathogen. Her laboratory works on diseases such as Typhoid, and the host-pathogen interaction with regard to the disease, with a view to develop a vaccine with a long-time memory against the pathogen. The team led by her has been successful in developing a treatment protocol for sepsis which uses a Bactericidal/permeability-increasing protein, a type of glycoprotein, which has been found to neutralize the bacterial endotoxin, one of the primary causative factors of sepsis. Her studies have been documented by way of a number of articles and ResearchGate, an online repository of scientific articles has listed 169 of them.
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They used more realistic conditions, including 3% sterile faeces to mimic the conditions in which many disinfectants were used. The Chick–Martin test was then widely used until replaced by more suitable tests not reliant on phenol and reflecting the conditions in which modern disinfectants are used. Calculations by Harriette Chick showed that the killing of bacteria by disinfectants followed first order kinetics. So, the bactericidal activity of a particular disinfectant at a given concentration can be expressed as a constant (k) calculated by employing the formula k = N/C·T where N is the number of surviving cells, C is the concentration of agent applied and T is the time for which the agent is applied, so k is inversely proportional to dose (C·T is collectively called dose).
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Ethylferrocene is an organometallic compound with the formula C12H14Fe.It was originally used in military or space field as an additive in rocket propellant, to promote the burning rate. But nowadays, ferrocenyl derivative has wide applications to biological and medical fields such as ferrocene- modified beta-lactam because of its physiological activity of anti-malarial, anti-tumor, bactericidal, anti-inflammatory, treatment of anemia, inhibition of enzymatic activity and so on by virtue of its unique structure and diverse properties, Good stability, low toxicity; Aromatic, easy for substitution reaction and modification; Hydrophobic, attacking a variety of enzymes in cells, DNA, RNA by going through cell membrane; Strong selectivity by its thickness of the sandwich structure, which can stop it close to the activity site of enzymes; Redox reversibility, which enable it to involve in metabolism by enzymes.
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Florey (pictured), Fleming and Chain shared a Nobel Prize in 1945 for their work on penicillin. In 1930, Cecil George Paine, a pathologist at the Royal Infirmary in Sheffield, successfully treated ophthalmia neonatorum, a gonococcal infection in infants, with penicillin (fungal extract) on November 25, 1930. In 1940, Australian scientist Howard Florey (later Baron Florey) and a team of researchers (Ernst Boris Chain, Edward Abraham, Arthur Duncan Gardner, Norman Heatley, Margaret Jennings, J. Orr-Ewing and G. Sanders) at the Sir William Dunn School of Pathology, University of Oxford made progress in making concentrated penicillin from fungal culture broth that showed both in vitro and in vivo bactericidal action. In 1941, they treated a policeman, Albert Alexander, with a severe face infection; his condition improved, but then supplies of penicillin ran out and he died.
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This combination of fine pore size and the bactericidal properties of colloidal silver produce an effective filter, killing over 98 percent of the contaminants that cause diarrhea, thus dramatically reducing public health problems in the communities that use them to purify potable water. He designed a mold for the filter and a special clay press that was operated with a tire jack.Science Guardian The Family of the Americas Association, a Guatemalan organization, conducted a one-year follow-up study on the initial Mazariegos- developed filter project, concluding that this filter helped to reduce the incidence of diarrhea in participating households by as much as 50 percent. Laboratory testing and field studies have been performed on the filter by various institutions, including MIT, Tulane University, University of Colorado and University of North Carolina.
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The history of radiation therapy or radiotherapy can be traced back to experiments made soon after the discovery of x-rays (1895), when it was shown that exposure to radiation produced cutaneous burns. Influenced by electrotherapy and escharotics — the medical application of caustic substances — doctors began using radiation to treat growths and lesions produced by diseases such as lupus, basal cell carcinoma, and epithelioma. Radiation was generally believed to have bactericidal properties, so when radium was discovered, in addition to treatments similar to those used with x-rays, it was also used as an additive to medical treatments for diseases such as tuberculosis where there were resistant bacilli. Additionally, because radiation was found to exist in hot spring waters which were reputed for their curative powers, it was marketed as a wonder cure for all sorts of ailments in patent medicine and quack cures.
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Murepavadin exhibits a specific and potent bactericidal activity in vitro against Pseudomonas aeruginosa including carbapenemase-producing and colistin-resistant isolates and was shown to be largely inactive against other Gram-negative bacteria, and Gram-positive bacteria. When tested in a large minimum inhibitory concentration surveillance study, against 1219 contemporary clinical isolates from the USA, Europe, and China of which 28% were multi-drug resistant strains, murepavadin exhibited a potent antimicrobial activity having a minimum inhibitory concentration for 90% of strains of 0.12 mg/L. There were no significant differences between geographic locations, and there was little difference in activity between multi-drug resistant/and non-multi-drug resistant isolates and no cross- resistance was observed with any other antimicrobial tested which supports its novel mechanism of action. Murepavadin showed outstanding in vivo efficacy in mouse sepsis (ED50 of 0.25 - 0.55 mg/kg) and lung and thigh infection models.
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In Neisseria gonorrhoeae it has been demonstrated that the antigenicity of LOS molecules can change during an infection due to the ability of these bacteria to synthesize more than one type of LOS, a characteristic known as phase variation. Additionally, Neisseria gonorrhoeae, as well as Neisseria meningitidis and Haemophilus influenzae, are capable of further modifying their LOS in vitro, for example through sialylation (modification with sialic acid residues), and as a result are able to increase their resistance to complement-mediated killing or even down-regulate complement activation or evade the effects of bactericidal antibodies. Sialylation may also contribute to hindered neutrophil attachment and phagocytosis by immune system cells as well as a reduced oxidative burst. Haemophilus somnus, a pathogen of cattle, has also been shown to display LOS phase variation, a characteristic which may help in the evasion of bovine host immune defenses.
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Evidence of epizootic outbreaks gained from an increase in ulcers noted among the fish populations seem to correlate to warmer seasons, suggesting a seasonal distribution in the incidence of the disease, dependent upon the waters temperature and salinity along with a decreased resistance caused by physiological changes experienced by the host during sexual maturity. Seawater is the most likely mode of transmission of the virulent cells of the pathogen. Once it comes into contact with the outer surface of the fish, it is able to adhere to skin and resist the bactericidal action of the skin mucus layer, thus suggesting that the skin is the site of entry into the host. This bacterium could therefore represent a significant threat to aquacultured fish species, especially those living in crowded and stressed conditions, where the spread of the disease could be accelerated through direct contact and thus pose a threat to humans.
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Linezolid is effective against all clinically important Gram-positive bacteria—those whose cell wall contains a thick layer of peptidoglycan and no outer membrane—notably Enterococcus faecium and Enterococcus faecalis (including vancomycin-resistant enterococci), Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA), Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus pyogenes, the viridans group streptococci, Listeria monocytogenes, and Corynebacterium species (the latter being among the most susceptible to linezolid, with minimum inhibitory concentrations routinely below 0.5 mg/L). Linezolid is also highly active in vitro against several mycobacteria. It appears to be very effective against Nocardia, but because of high cost and potentially serious adverse effects, authors have recommended that it be combined with other antibiotics or reserved for cases that have failed traditional treatment. Linezolid is considered bacteriostatic against most organisms—that is, it stops their growth and reproduction without actually killing them—but has some bactericidal (killing) activity against streptococci.
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Tigecycline is broad-spectrum antibiotic that acts as a protein synthesis inhibitor. It exhibits bacteriostatic activity by binding to the 30S ribosomal subunit of bacteria and thereby blocking the interaction of aminoacyl-tRNA with the A site of the ribosome.Tigecycline: A Novel Broad-Spectrum Antimicrobial: Pharmacology and Mechanism of Action Christine M. Slover, PharmD, Infectious Diseases Fellow, Keith A. Rodvold, PharmD and Larry H. Danziger, PharmD, Professor, Department of Pharmacy Practice, University of Illinois at Chicago, Chicago, IL In addition, tigecycline has demonstrated bactericidal activity against isolates of S. pneumoniae and L. pneumophila. It is a third-generation tetracycline derivative within a class called glycylcyclines which carry a N,N-dimethyglycylamido (DMG) moiety attached to the 9-position of tetracycline ring D. With structural modifications as a 9-DMG derivative of minocycline, tigecycline has been found to improve minimal inhibitory concentrations against Gram-negative and Gram-positive organisms, when compared to tetracyclines.
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" When Cohn began working under Dubos, as Moberg and Steinman explain, "the study of leukocytes was still in its infancy....It was also the time when the new science of cell biology was emerging at Rockefeller....This was making it possible to explore the world inside cells: electron microscopy for showing cell structures never before observed and centrifugation methods for separating and analyzing cellular constituents." Cohn and his colleague James G. Hirsch "used these new tools to address the question of whether phagocytes contained preformed bactericidal substances or whether these substances developed after foreign particles were engulfed. They isolated granules from the rest of the cell contents, used phase and electron microscopy to visualize them, and determined chemically that they were lysosomes, the cell organelles recently identified by Belgian biochemist Christian de Duve. These discoveries, which traced the phagocytic digestive system to the fusion of phagocytic vacuoles and lysosomes, became widely available to the community after Jim and Zan made a remarkable series of films showing living phagocytes discharging their abundant lysosomes to kill bacteria.
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LA is able to scavenge reactive oxygen and reactive nitrogen species in a biochemical assay due to long incubation times, but there is little evidence this occurs within a cell or that radical scavenging contributes to the primary mechanisms of action of LA. The relatively good scavenging activity of LA toward hypochlorous acid (a bactericidal produced by neutrophils that may produce inflammation and tissue damage) is due to the strained conformation of the 5-membered dithiolane ring, which is lost upon reduction to DHLA. In cells, LA is reduced to dihydrolipoic acid, which is generally regarded as the more bioactive form of LA and the form responsible for most of the antioxidant effects and for lowering the redox activities of unbound iron and copper. This theory has been challenged due to the high level of reactivity of the two free sulfhydryls, low intracellular concentrations of DHLA as well as the rapid methylation of one or both sulfhydryls, rapid side-chain oxidation to shorter metabolites and rapid efflux from the cell. Although both DHLA and LA have been found inside cells after administration, most intracellular DHLA probably exists as mixed disulfides with various cysteine residues from cytosolic and mitochondrial proteins.
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