Transient and Sustained Bacterial Adaptation following Repeated Sublethal Exposure to Microbicides and a Novel Human Antimicrobial Peptide

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Forbes, Sarah ; Dobson, Curtis B. ; Humphreys, Gavin J. ; McBain, Andrew J. (2014)
  • Publisher: American Society for Microbiology
  • Journal: Antimicrobial Agents and Chemotherapy, volume 58, issue 10, pages 5,809-5,817 (issn: 0066-4804, eissn: 1098-6596)
  • Related identifiers: doi: 10.1128/AAC.03364-14, pmc: PMC4187928
  • Subject: Susceptibility

Microbicides (biocides) play an important role in the prevention and treatment of infections. While there is currently little evidence for in-use treatment failures attributable to acquired reductions in microbicide susceptibility, the susceptibility of some bacteria can be reduced by sublethal laboratory exposure to certain agents. In this investigation, a range of environmental bacterial isolates (11 genera, 18 species) were repeatedly exposed to four microbicides (cetrimide, chlorhexidine, polyhexamethylene biguanide [PHMB], and triclosan) and a cationic apolipoprotein E-derived antimicrobial peptide (apoEdpL-W) using a previously validated exposure system. Susceptibilities (MICs and minimum bactericidal concentrations [MBCs]) were determined before and after 10 passages (P10) in the presence of an antimicrobial and then after a further 10 passages without an antimicrobial to determine the stability of any adaptations. Bacteria exhibiting >4-fold increases in MBCs were further examined for alterations in biofilm-forming ability. Following microbicide exposure, ≥4-fold decreases in susceptibility (MIC or MBC) occurred for cetrimide (5/18 bacteria), apoEdpL-W (7/18), chlorhexidine (8/18), PHMB (8/18), and triclosan (11/18). Of the 34 ≥4-fold increases in the MICs, 15 were fully reversible, 13 were partially reversible, and 6 were nonreversible. Of the 26 ≥4-fold increases in the MBCs, 7 were fully reversible, 14 were partially reversible, and 5 were nonreversible. Significant decreases in biofilm formation in P10 strains occurred for apoEdpL-W (1/18 bacteria), chlorhexidine (1/18), and triclosan (2/18), while significant increases occurred for apoEdpL-W (1/18), triclosan (1/18), and chlorhexidine (2/18). These data indicate that the stability of induced changes in microbicide susceptibility varies but may be sustained for some combinations of a bacterium and a microbicide.
  • References (72)
    72 references, page 1 of 8

    1. Gilbert P, Moore LE. 2005. Cationic antiseptics: diversity of action under a common epithet. J. Appl. Microbiol. 99:703-715. .1111/j.1365-2672.2005.02664.x.

    2. Gaonkar TAP, Sampath LABA, Modak SMP. 2003. Evaluation of the antimicrobial efficacy of urinary catheters impregnated with antiseptics in an in vitro urinary tract model. Infect. Control Hosp. Epidemiol. 24:506 - 513.

    3. Sampath LABA, Tambe SMP, Modak SMP. 2001. In vitro and in vivo efficacy of catheters impregnated with antiseptics or antibiotics: evaluation of the risk of bacterial resistance to the antimicrobials in the catheters. Infect. Control Hosp. Epidemiol. 22:640 - 646. /501836.

    4. Silver S, Phung le T, Silver G. 2006. Silver as biocides in burn and wound dressings and bacterial resistance to silver compounds. J. Ind. Microbiol. Biotechnol. 33:627- 634.

    5. Broxton P, Woodcock PM, Heatley F, Gilbert P. 1984. Interaction of some polyhexamethylene biguanides and membrane phospholipids in Escherichia coli. J. Appl. Bacteriol. 57:115-124. /j.1365-2672.1984.tb02363.x.

    6. McMurry LM. 1998. Triclosan targets lipid synthesis. Nature 394:531.

    7. Blanco MA, Negro C, Gaspar I, Tijero J. 1996. Slime problems in the paper and board industry. Appl. Microbiol. Biotechnol. 46:203-208. http: //

    8. Pereira MO, Vieira VM, Beleza VM, Melo LF. 2001. Comparison of two biocides- carbamate and glutaraldehyde-in the control of fouling in pulp and paper industry. Environ. Technol. 22:781-790. /10.1080/095933322086180318.

    9. Condell O, Condell C, Iversen S, Cooney KA, Power C, Walsh C, Burgess S, Fanning. 2012. Efficacy of biocides used in the modern food industry to control Salmonella enterica, and links between biocide tolerance and resistance to clinically relevant antimicrobial compounds. Appl. Environ. Microbiol. 78:3087-3097. .07534-11.

    10. Quintavalla S, Quintavalla L, Vicini. 2002. Antimicrobial food packaging in meat industry. Meat Sci. 62:373-380. -1740(02)00121-3.

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