More info about antibacterials

Introduction to antibacterials

Questions and answers about antibacterials

Table of common antibacterials
 Antibacterial Agents: Annotated References

General references
  1. Cardoso CL, Pereira HH, Zequim JC, Guilhermetti M (1999). "Effectiveness of hand-cleansing agents for removing Acinetobacter baumannii strain from contaminated hands." Am J Infect Control 27(4): 327-331. The effectiveness of plain liquid soap, 70% ethyl alcohol, 10% povidone-iodine, and 4% chlorhexidine gluconate in removing Acinetobacter baumannii from artificially contaminated hands of 5 volunteers was examined. All agents were effective when hands were contaminated with 103 (colony forming units) cfu. For hands contaminated with 106 cfu, all agents were > 90% effective, with ethyl alcohol and povidone-iodine being most effective.

  2. Charbonneau DL, Ponte JM, Kochanowski BA. (2000). "A method of assessing the efficacy of hand sanitizers: use of real soil encountered in the food service industry." J. Food Prot 63(4): 495-501. A method to assess efficacy of hand disinfectants used in the food service industry was developed. The method uses soil from fresh meat in order to quantify bacteria encountered and transferred during food preparation. Para-chloro-meta-xylenol and triclosan were tested using protocol. Dose-dependent results were obtained. Other studies showed that handwashing using mild soap and water for twenty seconds was more effective than use of a 70% alcohol hand sanitizer.

  3. Guilhermetti M, Hernandes SE, Fukushigue Y, Garcia LB, Cardoso CL (2001). "Effectiveness of hand-cleansing agents for removing methicillin-resistant Staphylococcus aureus from contaminated hands." Infect Control Hosp Epidemiol 22(2): 105-108. The effectiveness of plain liquid soap, 70% ethyl alcohol, 10% povidone-iodine liquid soap, and 4% chlorhexidine gluconate in removing methicillin-resistant Staphylococcus aureus from contaminated hands was studied. Five volunteers were artificially contaminated with methicillin-resistant Staphylococcus aureus (light and heavy contamination). Significant differences were found with treatments: ethyl alcohol and povidone-iodine liquid soap were more effective than the other treatments in removing light contamination or heavy contamination, although all treatments reduced contamination by about 95%.


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  4. Herruzo-Cabrera R, Garcia-Caballero J, Martin-Moreno JM, Graciani-Perez-Regadera MA, Perez-Rodriguez J (2001). "Clinical assay of N-duopropenide alcohol solution on hand application in newborn and pediatric intensive care units: control of an outbreak of multiresistant Klebsiella pneumoniae in a newborn intensive care unit with this measure." Am J Infect Control 29(3): 162-167. An alcohol solution of N-duopropenide was compared to handwashing with nonantiseptic soap in removing a multiresistant strain of Klebsiella pneumoniae from hands of staff in a newborn intensive care unit. N-duopropenide in alcohol was found to be significantly more effective.

  5. Larson EL, Aiello AE, Bastyr J, Lyle C, Stahl J, Cronquist A, Lai L, Della-Latta P (2001). "Assessment of two hand hygiene regiments for intensive care unit personnel." Crit Care Med 29(5): 1083-1084. Skin condition and skin microbiology of intensive care unit personnel was compared using one of two randomly assigned hand hygiene regimens (2% chlorhexidine gluconate-containing traditional antiseptic wash or a waterless rub containing 61% ethanol with emollients). Comparisons were made at 0 days, 1 day, 2 weeks and 4 weeks. No significant differences were found in colony-forming units of bacteria between participants in either group; however, less time was required for the alcohol regimen.

  6. Kusumaningrum HD, vanPutten MM, Rombouts FM, Beumer RR (2001). "Effects of antibacterial dishwashing liquid on foodborne pathogens and competitive microorganisms in kitchen sponges." J Food Protection 65(1): 61-65. The effects of an antibacterial dishwashing liquid on reduction of Escherichia coli, Salmonalla Enteritidis, Staphyloccus aureus, and Bacillus cereus were invested in a suspension test and in used sponges that contained or did not contain food residues. Staphylococcus aureus and Bacillus cereus were found to be susceptible to low concentrations of antibacterial dishwashing liquid in suspension tests, whereas the other organisms were not. At higher concentrations, all organisms were susceptible. In used sponges containing food residues, the dishwashing liquid was not effective at low or high concentrations in removing test or competing organisms.


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  7. Pereira LJ, Lee GM, Wade KJ. (1997). "An evaluation of five protocols for surgical handwashing in relation to skin condition and microbial counts." J Hosp Infect 36(1): 49-65. Five protocols for surgical handwashing were evaluated for efficiency of removal of microorganisms and drying effects on skin. Protocols included: (1) 5 min initial scrub and three 3.5 min consecutive scrubs using 4% chlorhexidine gluconate; (2) 3 min initial scrub and 2.5 min consecutive scrubs with clorhexidine gluconate; (3) initial scrub of 3 min and 2.5 min consecutive scrubs with 5% povidone iodine and 1% triclosan; (4) 2 min initial scrub with 4% chlorhexidine gluconate followed by 30 second application of 70% isopropanol/0.5% chlorhexidine gluconate and a 30 second application of 70% isopropanol /0.5% chlorhexidine gluconate for consecutive scrubs; (5) 2 min initial scrub with 4% chlorhexidine gluconate followed by 30 second application of 70% ethanol/0.5% chlorhexidine gluconate and a 30 second application of 70% ethanol/0.5% chlorhexidine gluconate for consecutive scrubs. End points included microbial counts and hand skin conditions. Samples for microbial analysis were collected before, immediately after and 2h after skin scrub. Protocols using alcohol-based antiseptics were found to have the lowest post-scrub numbers of colony forming units. Subjects reported that alcohol-based antiseptic protocols were less drying, although objective measures showed no difference.

  8. Perencevich EN, Wong MT, Harris AD. (2001). "National and regional assessment of the antibacterial soap market: A step toward determining the impact of prevalent antibacterial soaps." Am J Infect Control 29(5): 281-283. A physician-performed survey of 23 stores in 10 states was conducted from December 1999 to April 2000 to determine the number of national brand liquid and bar soaps and the percent of each type of soap containing antibacterial agents. Venders included national chain stores, regional grocery stores and Internet stores. Antibacterial agents were found to be present in 76% of all liquid soaps and 29% of all bar soaps, or an overall content of 45% of all products. No difference in distribution pattern was seen among the different types of vendors.


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  9. Rotter M. (1996). "Procedures for hand hygiene in German-speaking countries [article in German]" Zentralbl Hyg Umweltmed 199(2-4): 334-349. Review article describes conditions under which different methods of hand hygiene should be employed. Transient contaminating bacteria can be removed by handwashing, hygienic handwash and hygienic hand rub (in order of increasing efficacy). Duration of treatment will influence the reduction of microbes. Disinfection of clean hands by rubbing and wetting with 60% n-propanol for a period fo 3 minutes can achieve a reduction of microbial release between 2.0 and 2.4 orders of magnitude. In contrast, washing with preparations containing povidone-iodine, chlorhexidine gluconate or triclosan reduce bacterial release within 205 minutes by about 0.5 to 1.2 orders of magnitude.

  10. Toshima Y, Ojima M, Yamada H, Mori H, Tonomura M, Hioki Y, Koya E (2001). "Observation of everyday hand-washing behavior of Japanese, and effects of antibacterial soap." Int J Food Microbiol 68(1-2): 83-91. Washing with soap not containing antibacterial agents reduced 95% of total coliform transferred from ground meat; however, washing with an antibacterial soap further reduced coliform count.

  11. Zaragoza M, Salles M, Gomez J, Bayas JM, Trilla A (1999). "Handwashing with soap or alcoholic solutions? A randomized clinical trial of its effectiveness." Am J Infect Control 27(3): 258-261. The effectiveness of hygienic soap and water handwashing procedures and handwashing with alcoholic solutions was compared among health care workers in wards and intensive care units of a large public university hospital in Barcelona. The alcoholic handwashing procedure was found to be significantly more effective in removing colony forming units (determined by comparison of colony forming units found on hands before and after washing procedure).
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Triclosan
  1. Adolfsson-Erici M, Pettersson M, Parkkonen J, Sturve J (2001). "Triclosan, a commonly used bactericide found in human milk and in the aquatic environment in Sweden." Chemosphere 2001 (in press). Triclosan was found in three of five randomly selected human milk samples, in several consumer products that were treated with antibacterial agents, and in the bile of fish exposed to municipal wastewater, even when the wastewater had undergone several bacterial degradation processes.

  2. Bamber AI, Neal TJ. (1999). "An assessment of triclosan susceptibility in methicillin-resistant and methicillin-sensitive Staphylococcus aureus." J Hosp Infect 41(2):107-109. An agar dilution method was used to determine the minimum inhibitory concentration of triclosan for 186 isolates of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA). Fourteen isolates (7.5%) of strains tested were found to have a minimum inhibitory concentration > 1 ppm. No difference in sensitivity to triclosan was found in MRSA and MSSA isolates.

  3. Chuanchuen R, Beinlich K, Hoang TT, Becher A, Karkhoff-Schweizer RR, Schweizer HP. (2001). "Cross-resistance between triclosan and antibiotics in Pseudomonas aeruginosa is mediated by multidrug efflux pumps: exposure of a susceptible mutant strain to triclosan selects nfxB mutants overexpressing MexCD-OprJ." Antimicrob Agents Chemother 45(2): 428-432. Exposure of a susceptible mutant strain of Pseudomonas aeruginosa to triclosan selected for bacteria expressing multidrug resistance at high frequencies. The resistant bacteria overexpressed a MexCD-OprJ efflux system, and exhibited minimum inhibitory concentration increases of up to 500 fold, including a 94-fold MIC for ciprofloxacin.

  4. Cutter CN. (1999). "The effectiveness of triclosan-incorporated plastic against bacteria on beef surfaces." J Food Prot 63(5): 474-479. Plastic containing 1,500 ppm triclosan was evaluated in plate overlay or meat assays to determine under which conditions bacterial populations were reduced. In plate overlay assays, the triclosan-impregnated plate was found to inhibit growth of Brochothrix thermosphacta ATCC 11509, Salmonella typhimurium ATCC 14028, Staphylococcus aureus ATCC 12598, Bacillus subtilis ATCC 6041, Shigella flexneri ATCC 12022, Escherichia coli ATCC 25922, and several strains of E. coli 0157:H7. In the meat assays meat surfaces were inoculated with bacterial strains and kept at either 4 or 12 degrees C. Under the experimental conditions employed, the triclosan-impregnated plate containing 1,500 ppm triclosan was not found to reduce bacterial populations on meat surfaces.


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  5. Faoagali JL, George N, Fong J, Davy J, Dowser M. (1999). "Comparison of the antibacterial efficacy of 4% chlorhexidine gluconate and 1% triclosan handwash products in an acute clinical ward." Am J Infect Control 27(4): 320-326. The effects of 4% chlorhexidine gluconate and 1% triclosan handwashes were studied. Subjects enrolled in the study were clinical staff in a specialist surgical unit. Composition of the hand bacterial flora of enrolled subjects was determined in pre- and post-handwash samples taken three different times throughout the day. Counts for total bacteria and methicillin-resistant Staphylococcus aureus and coliforms were conducted. Clorhexidine gluconate was found to be more effective than triclosan in removing gram-negative bacteria whereas triclosan was found to be more effective in eliminating methicillin-resistant S. aureus.

  6. Hay AG, Dees PM, Sayler GS. (2001). "Growth of a bacterial consortium on triclosan." FEMS Microbiol Ecol 36(2-3): 105-112. A consortium of bacteria capable of growing on triclosan was selected by growing bacteria in a medium containing triclosan as the only carbon source. Approximately 35% of the dichloro ring of triclosan was converted to CO2 .

  7. Heath RJ, Li J, Roland GE, Rock CO (2000). "Inhibition of the Staphylococcus aureus NADPH-dependent enoyl-acyl carrier protein reductase by triclosan and hexachlorophene." J Biol Chem 275(7) 4654-4659. Enoyl-acyl carrier protein reductase (FabI), which is an essential enzyme in type II fatty acid synthase systems, is a target for antibacterial drugs, including triclosan. The FabI component of Staphylococcus aureus (saFabI) was identified, and its properties were compared with Escherichia coli FabI (ecFabI). Triclosan and hexachlorophene inhibited both ecFabI and saFabI. The triclosan-resistant ecFabI(G93V) protein was also refractory to hexachlorophene inhibition, suggesting that both hexaclorophene and triclosan bind at the FabI active site. However, missense mutations of the S. aureus FabI gene did not exhibit cross-resistance to hexachlorophene.

  8. Heath RJ, Rubin JR, Holland DR, Zhang E, Snow ME and Rock CO (1999). "Mechanism of triclosan inhibition of bacterial fatty acid synthesis" J. Biol Chem 274 (16): 11110-11114. Resistance to triclosan in Escherichia coli can be acquired through a missense mutation in the gene coding for enoyl-[acyl]-carrier protein reductase, (FabI). Expression of FabI[G93V], the missense mutation was examined. The specific activity and substrate affinities of FabI[G93V] is similar to FabI. Two different binding assays establish that triclosan dramatically increases the affinity of FabI for NAD+, but, in contrast, does not increase the binding of NAD+ to FabI[G93V]. The formation of a noncovalent "bi-substrate" complex accounts for the effectiveness of triclosan as a FabI inhibitor. Mutations in the FabI active site that interfere with the formation of a stable FabI-NAD+-triclosan ternary complex result in resistance to the drug.


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  9. Jones RD, Jampani HB, Newman JL, Lee AS. "Triclosan: a review of effectiveness and safety in health-care settings." Am J Infect Control 2000 28(2): 184-196. Review of the utility and effectiveness of 1% triclosan solutions as antimicrobial agents in high-risk, high-frequency handwashing situations. Triclosan is seen as an immediate, persistent, broad-spectrum antimicrobial agent suitable for repeated use in health-care settings.

  10. Kalyon BD and Olgun U (2001). "Antibacterial efficacy of triclosan-incorporated polymers." Am J Infect Control 29(2): 124-125. To assess the efficacy of triclosan-impregnated polymers prepared by melt-mixing as inhibitors of bacterial growth, polystyrene discs into which triclosan was melt-mixed were tested against liquid cultures of two bacterial strains: E. coli Y1090 and B. thuringiensis. Bacterial growth was initially slower in cultures exposed to triclosan-impregnated polymers. However, over extended periods, no differences in growth rate were found in cultures exposed to triclosan-impregnated polymers and control cultures (exposed to non-impregnated polymers). When triclosan-impregnated discs were brought into contact with ethanol-water solutions, extraction of triclosan plateaued at 75 minutes. Calculations indicated that approximately 0.06% of the incorporated triclosan migrated from the polymer. The authors conclude that triclosan at the disc surface dissolves into liquids, while the remainder of the triclosan is immobilized and is not effective as an antibacterial agent. It is further suggested that triclosan-incorporated polymers may be ideal for selection of triclosan-resistant strains of bacteria to grow.

  11. Levy SB. (2000). "Antibiotic and antiseptic resistance: impact on public health." Pediatr Infect Dis J 19(10suppl): S120-122. Such factors as moving patients from hospitals to homes for continued treatment means that both antibacterial agents and antibiotics are being used more extensively outside hospital settings. Today, antibacterial compounds are found in soaps, disinfectants, clothes and plastic products. Often the antibacterial compound found in these products is triclosan. Laboratory findings indicate that increased production of the AcrAB efflux pump, which results from overexpression of the mar regulatory locus can confer multiple antibiotic resistance. Findings also indicate that some triclosan resistant mutants also exhibit overexpression of the mar regulatory locus. Hence, triclosan could select for antibiotic resistance or antibiotics could select for triclosan resistance. It is essential that the general public and health professionals be educated about the rational use of drugs affecting the mix of microbes in the environment. Most bacteria have essential roles that are crucial to our survival. Prudent use of both antibiotics and antibacterials must be championed to achieve and maintain a balanced microbial environment.

  12. Levy CW, Roujeinikova A, Sedelnikova S, Baker PJ, Stuitje A, Slabras AR, Rice DW, Rafferty JB (1999). "Molecular basis of triclosan activity." Nature 398: 383-384. Triclosan is an inhibitor of enoyl-acyl carrier protein reductase, thus inhibiting the final step in the fatty acid synthase cycle. Analysis of an electron density map reveals that triclosan binds at a site adjacent to the nicotinamide ring of NAD+, the nucleotide cofactor product of the reduction step. Single amino acid substitutions at one of three positions of the reductase confer resistance to triclosan in E. coli K12. The highest level of resistance, approximately 100 fold, is the result of valine substitution for glutamate at position 93. The valine side chain sterically inhibits binding of triclosan.


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  13. McMurry LM, Oethinger M, and Levy S. (1998). "Overexpression of marA, soxS or acrAB produces resistance to triclosan in laboratory and clinical strains of Escherichia coli." FEMS Microbiology Letters 166(2): 305-309. Overexpression of the multidrug efflux pump locus acrAB, or of marA or soxS, both of which encode positive regulators of acrAB, decreased susceptibility to triclosan by 2-fold. Deletion of the acrAB locus increased the susceptibility to triclosan approximately 10-fold. Four of five clinical E. coli strains that overexpressed marA or soxS also showed enhanced triclosan resistance. The acrAB locus was involved in the effects of triclosan upon both cell growth rate and cell lysis.

  14. McMurry LM, Oethinger M, Levy SB (1998). "Triclosan targets lipid synthesis." Nature 394: 531-532. Triclosan-resistant mutants of E. coli were isolated and characterized. Triclosan resistance was found associated with mutations on the fab1 gene which encodes enoyl-[acyl]-carrier protein reductase. Mutations were associated with several residues that are linked to the NADH binding site. To demonstrate that the target protein is the product of the gene coding for enoyl-[acyl]-carrier protein, wild type E.coli was treated with triclosan and other drugs (as controls) and incorporation of radio-labeled acetate into fatty acids was measured. Diazoborine (a specific inhibitor of enoyl[-acyl]-carrier protein reductase and triclosan were found to inhibit incorporation into fat by 93% and 92%, respectively. In contrast, chloramphenicol, a protein synthesis inhibitor, and ciprofloxacin, an inhibitor of DNA synthesis, had no effect.

  15. Meade MJ, Waddell RL, Callahan TM. (2001) "Soil bacteria Pseudomonas putida and Alcaligenes xylosoxidans subsp. denitrificans inactivate triclosan in liquid and solid substrates." FEMS Microbiol Letters 204(1): 45-48. Bacteria with high levels of triclosan resistance were isolated from compost, water and soil samples. Two bacterial strains were able to use triclosan as a sole carbon source and to clear particulate triclosan from agar. Decreases in triclosan were measured by HPLC. Using bioassay techniques, it was demonstrated that triclosan was inactivated in liquid cultures or while embedded in plastic by growth of resistant strains, allowing growth of triclosan-sensitive bacteria to proceed.

  16. Randall, LP, Cooles SW, Sayers AR, Woodward MJ. (2001). "Association between cyclohexane resistance in Salmonella of different serovars and increased resistance to multiple antibiotics, disinfectants and dyes." J Med Microbiol 50(10): 919-924. Three hundred and eighty eight strains of Salmonella, comprising 35 serotypes were tested for cyclohexane resistance and resistance to a wide range of antibiotics, disinfectants, and dyes. Ten percent of the tested strains exhibited cyclohexane resistance. Most of the resistant isolates were from poultry. Resistant strains were significantly more resistant than susceptible strains to ampicillin, chloramphenicol, ciprofloxacin, erythromycin, nalidixic acid, tetracycline, trimethoprim, cetrimide and triclosan. Multiresistance patterns were typical of those caused by efflux pumps.


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  17. Russell AD. (2000). "Do biocides select for antibiotic resistance?" J Pharm Pharmacol 52(2): 227-233. Gram-negative bacteria that have developed resistance to cationic biocides may also be less susceptible or resistant to some antibiotics. This may be due to outer membrane changes or to efflux. In staphylococci, the efflux associated with the qacA/ B gene system confers low-level resistance to such agents as chlorhexidine salts and quaternary ammonium compounds. In Escherichia coli, a linkage between low-level resistance to triclosan and to antibiotics has been reported. One of the issues of debate has been the use of biocides at concentrations significantly below those used clinically. It remains to be determined how an increase to low-level resistance to cationic biocides can be held responsible for the selection of antibiotic-resistant bacteria.

  18. Saunders KA, Greenman J, and McKenzie C (2000). "Ecological effects of triclosan and triclosan monophosphate on defined mixed cultures of oral species grown in continuous culture." J Antimicrob Chem 45 (4): 447-452. The effects of triclosan and triclosan monophosphate were studied using a continuous culture microcosm model. Two conditions were simulated, a caries-like state and a periodontal disease-like state. Steady-state chemostats were pulsed with triclosan or triclosan monophosphate and changes in the ecological composition noted after 6 h. Significant ecological shifts were apparent following pulses of triclosan. The streptococci became the dominant group. Gram-negative anaerobes including Fusobacterium sp.were markedly inhibited. It is concluded that in the periodontal disease state, both triclosan and triclosan monophosphate affected the Gram-negative anaerobes to a greater extent than the Gram-positive bacteria.

  19. Schweizer HP (2001). "Triclosan: a widely used biocide and its link to antibiotics." FEMS Microbiol Lett 202 (1): 1-7. Recent findings indicate that triclosan inhibits a specific fatty acid synthetic enzyme in bacteria, enoyl-[acyl]-carrier protein reductase in both gram positive and gram negative bacteria. Mechanisms of triclosan resistance, including target enzyme mutations, increased production of the target enzyme and efflux mechanisms are the same types of mechanisms that are found in antibiotic resistance. It is suggested that the widespread use of triclosan-containing antiseptics and disinfectants may lead to antimicrobial resistance.

  20. Slater-Radosti C, Van Aller G, Greenwood R, Nicholas R, Keller PM, DeWolfe WE, Fan F, Payne DJ, Jaworski DD (2001). "Biochemical and genetic characterization of the action of triclosan on Staphylococcus aureus." J Antimicrob Chemother (48 (1): 1-6. Staphylococcus aureus is a target strain of triclosan. A strain of Staphylococcus aureus overexpressing the enzyme enoyl-[acyl]-carrier protein reductase as demonstrated through Western blotting, was examined for response to triclosan. Both the minimal inhibitory concentration of triclosan and the number of enzyme molecules of enoyl-[acyl]-carrier protein in this organism were increased in this organism. Findings provide further support for the mode of action of triclosan.


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  21. Suller MT, Russell AD (1999). "Antibiotic and biocide resistance in methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus." J Hosp Infect 43(4) 281-291. Susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA) to chlorhexidine (CHX), the quaternary ammonium compounds cetylpyridinium chloride (CPC) and benzalkonium chloride (BC), triclosan, dibromopropamidine isethionate (DBPI) and triclocarban were compared. Although there were some differences between the two strains, both were relatively sensitive to most antimicrobial agents. The MRSA and MSSA strains were equally susceptible to killing effects of triclosan. Attempts to select for staphylococcal strains with increased resistance to triclosan, CPC or CHX, using disc diffusion, step-wise broth, or repeated exposure/recovery techniques, were only partially successful, and resistance was found to be unstable. Susceptibilities of vancomycin-resistant and vancomycin-sensitive strains of enterococcus were also compared and found to be similar in terms of minimum inhibitory concentration testing and time-kill studies.

  22. Suller MT, Russell AD (2000). "Triclosan and antibiotic resistance in Staphylococcus aureus." J Antimicrob Chemother 46(1): 11-18. Clinical isolates of S. aureus were tested for susceptibility to triclosan and several antibiotics. The minimum inhibitory concentration of triclosan ranged from 0.025 to 1 mg/L in the isolates, and some, but not all, strains were resistant to several antibiotics and showed low-level resistance to triclosan. S. aureus mutants with enhanced resistance to triclosan (</=1 mg/L) were isolated. Several S. aureus mutants with enhanced resistance to triclosan were isolated. Resistance was shown to be a stable, heritable characteristic and was not associated with acquisition of plasmid encoding mupirocin resistance. These mutants were not more resistant to antibiotics than the parent strain. The continuous exposure of a triclosan-sensitive S. aureus strain to sub-MIC concentrations of triclosan for 1 month did not result in decreased susceptibility to triclosan or to several antibiotics tested.

  23. Susman E (2001). "Too clean for comfort." Environmental Health Perspectives 109 (1): A18. Summary of presentation at annual meeting of Infectious Diseases Society of America in September 2000 by Eli N. Perencevich who, with colleagues examined 395 national brand liquid soaps and 733 bar soaps taken from stores in 10 states across U.S. Seventy six percent of liquid and 30% of bar soaps examined contained triclosan. It was suggested that no evidence exists to support claims that antibacterial compounds in household products prevent infection, and such compounds may kill off sensitive bacteria allowing the resistant strains, that may be detrimental to health, to remain.

  24. Swofford HW (2001). "Antibacterial efficacy of polymers containing triclosan and other antimicrobial additives." Am J Infect Contol 29(6): 428-429. Response to article of Kalyon and Olgun regarding efficacy of triclosan as antimicrobial agent in polymers. Using standardized testing method, polypropylene cutting board treated with triclosan was demonstrated to inhibit growth of E. coli O157 from 71,000 cfu to <10 cfu at 24 hours. Control untreated cutting board had inoculum of 71,000 cfu that increased to 94,000 cfu at 24 hours. Similar results were reported for several other bacterial strains. Author suggests that results of Kalyon and Olgun can be attributed to experimental design, which used liquid culture in contact with triclosan-impregnated polymer. Triclosan was not released from the polymer, thus not affecting growth of bacteria in liquid culture.


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  25. Tambe SM, Sampath L, Modak SM (2001). "In vitro evaluation of the risk of developing bacterial resistance to antiseptics and antibiotics used in medical devices." J Antimicrob Chemother 47(5): 589-598. To evaluate the risk of developing resistance in Staphylococcus epidermidis to antibiotics and antibacterial agents impregnated in central venous catheters, cultures were passaged 10-20 times through subinhibitory concentrations of different antimicrobials and the minimum inhibitory concentrations of antimicrobials and antibacterials were determined. Results varied according to the antibiotic or antimicrobial tested. The minimum inhibitory concentration of triclosan alone increased eight-fold.

  26. Tattawasart U, Maillard JY, Furr JR, Russell AD (1999). "Development of resistance to chlorhexidine diacetate and cetylpyridinium chloride in Pseudomonas stutzeri and changes in antibiotic susceptibility." J Hosp Infect 42(3) 219-229. Strains of Pseudomonas stutzeri developed stable resistance to chlorhexidine diacetate or cetylpyridinium chloride when exposed to gradually increasing concentrations of either. These strains also showed reduced sensitivity to triclosan and to some antibiotics. It is proposed that alterations in the cell envelope are likely to be responsible for non-specific changes in sensitivity. Attempts to transfer resistance by conjugation were unsuccessful.

  27. Tierno PM (1999). "Efficacy of triclosan." Am J of Infect Control 27 (1): 71-72. Response to the Association for Professionals in Infection Control and Epidemiology (APIC) position on the use of antimicrobial household products. Author points out that triclosan has been used for approximately 30 years in a number of household products. Triclosan is a broad-spectrum antimicrobial that can act on fungi, viruses and bacteria, and, at high concentrations is bacteriocidal. Author feels that laboratory studies of mutant strains demonstrate tolerance, rather than resistance to triclosan, and do not represent development of resistance.

  28. Villalain J, Mateo CR, Aranda FJ, Shapiro S, Micol V (2001). "Membranotropic effects of the antibacterial agent triclosan." Arch Biochem Biophys 390 (1): 128-136. The effects of triclosan on bacterial membranes were examined by performing leak titrations on different oral bacteria and by studying the interaction of triclosan on model membranes. Negligible efflux of cellular material was found in one bacterial strain at minimal inhibitory concentrations; no efflux from a second strain was found at this same concentration. Triclosan was found to lower the temperature of the transition from liquid to crystalline phase transition of several compounds found in membrane lipids. Results suggest that antibacterial effects of triclosan are mediated partly through destabilization of membrane structures which compromises their functional integrity. This can occur without lysis of bacterial cells.
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Triclocarban
  1. Breneman DL, Hanifin JM, Berge CA, Keswick BH, Neumann PB (2000). "The effect of antibacterial soap with 1.5% triclocarban on Staphylococcus aureus in patients with atopic dermatitis." Cutis 66(4): 296-300. Fifty patients with atopic dermatitis were enrolled in a double-blind study to determine the effectiveness of antibacterial soap on the number of Staphylococcus aureus on skin and clinical improvement of dermatitis. Soap used in treatment was either a placebo or contained 1.5% triclocarban. Significant improvements were found in patients using triclocarban-containing soap. This included reduction in number of Staphylococcus aureus on skin, total bacterial count, and dermatological improvement.

  2. Garibaldi RA (1988). "Prevention of intraoperative wound contamination with chlorhexidine shower and scrub." J Hosp Infect 11 Suppl B: 5-9. Prospective controlled clinical trial examining the efficacy of 4% chlorhexidine gluconate and triclocarban medicated soap in reducing skin colonization at site of surgical incision. Skin cultures from patients who showered with clorhexidine gluconate showed significantly fewer bacteria than those taken from patients who showered with triclocarban.

  3. Heinze JE, Yackovich F (1988). "Washing with contaminated bar soap is unlikely to transfer bacteria." Epidemiol Infect 101(1): 135-142. Sixteen panelists washed with bar soap containing 0.8% triclocarban inoculated with Escherichia coli and Pseudomonas aeruginosa. After washing, none of the panelists were found to have detectable levels of either bacterial strain on their hands. Results support the frequent use of soap and water for handwashing to prevent the spread of disease.
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Sodium hypochlorite (bleach)
  1. Bottone EJ, Perez AA2nd, Oeser JL (1994) "Loofah sponges as reservoirs and vehicles in the transmission of potentially pathogenic bacterial species to human skin." J Clin Microbiol 32(2): 469-472. The role of loofah sponges in supporting growth of bacteria was assessed. Sterile loofah fragments enhanced growth of numerous gram negative and gram positive bacteria. The ability of loofah sponges to support bacterial growth is augmented by epithelial cells that are entrapped in the sponge. It is recommended that sponges be decontaminated at regular intervals by 10% hypochlorite bleach.

  2. Kearns AM, Freeman R, Lightfoot NF (1995). "Nosocomal enterococci: resistance to heat and sodium hypochlorite." J Hosp Infect 30(3): 193-199. Six strains of Enterococcus faecium and Enterococcus faecalis were investigated to determine their resistance to heat and to sodium hypochlorite. Three strains withstood treatment by 150 ppm available chlorine (from hypochlorite) for a period of 15 minutes. All enterococci survived the temperatures and holding times specified by the Department of Health for disinfection of 'foul and used' or 'infected' linen (65 degrees C for 10 min or 71 degrees C for 3 min). In addition, four strains of E. faecium were able to survive the British Standard for heat disinfection of bedpans (80 degrees C for 1 min).

  3. Nelson-Filho P, Macari S, Faria G, Assed S, Ito IY (2000). "Microbial contamination of toothbrushes and their decontamination." Pediatr Dent 22(5): 381-384. Toothbrushes used by 19 children once a day for five consecutive days were immersed in 0.12% chlorhexidine gluconate, 1% sodium hypochlorite or sterile tap water and tested for efficacy in decontamination of streptococci. Chlorhexidine gluconate or sodium hypochlorite treatment removed bacteria; sterile water did not remove streptococci.

  4. Saurina G, Landman D, Quale JM (1997). "Activity of disinfectants against vancomycin-resistant Enterococcus faecium." Infect Control Hosp Epidemiol 18(5): 345-357. Commonly used disinfectants were examined for activity against eight strains of vancomycin-resistant enterococci. Isopropyl alcohol and sodium hypochlorite were highly effective; hydrogen peroxide was ineffective for all strains. Other effective agents included three phenolic and three quarternary ammonium compounds.

  5. Schwartz RS, Hensley DH, Bradley DV (1996). "Immersion disinfection of irreversible hydrocolloid impression in pH-adjusted sodium hypochlorite. Part 1: Microbiology." Int J Prosthodont 9(3) 2117-222. Study evaluated the antimicrobial activity of sodium hypochlorite at progressively lower pH levels on a metal model of a contaminated dental arch. When immersed in solutions from pH 7 to 11, 99.99% or greater reduction in microorganisms was seen.


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