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. 2015 Aug;70(8):2241-8.
doi: 10.1093/jac/dkv109. Epub 2015 May 7.

Parallel evolutionary pathways to antibiotic resistance selected by biocide exposure

Mark A Webber  1 , Rebekah N Whitehead  2 , Manuella Mount  2 , Nick J Loman  3 , Mark J Pallen  4 , Laura J V Piddock  2
Affiliations

Parallel evolutionary pathways to antibiotic resistance selected by biocide exposure

Mark A Webber et al. J Antimicrob Chemother. 2015 Aug.

Abstract

Objectives: Biocides are widely used to prevent infection. We aimed to determine whether exposure of Salmonella to various biocides could act as a driver of antibiotic resistance.

Methods: Salmonella enterica serovar Typhimurium was exposed to four biocides with differing modes of action. Antibiotic-resistant mutants were selected during exposure to all biocides and characterized phenotypically and genotypically to identify mechanisms of resistance.

Results: All biocides tested selected MDR mutants with decreased antibiotic susceptibility; these occurred randomly throughout the experiments. Mutations that resulted in de-repression of the multidrug efflux pump AcrAB-TolC were seen in MDR mutants. A novel mutation in rpoA was also selected and contributed to the MDR phenotype. Other mutants were highly resistant to both quinolone antibiotics and the biocide triclosan.

Conclusions: This study shows that exposure of bacteria to biocides can select for antibiotic-resistant mutants and this is mediated by clinically relevant mechanisms of resistance prevalent in human pathogens.

Keywords: MDR; disinfectant; efflux.

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Figures

Figure 1.
Figure 1.
Comparison of mutant selection between sub-culture and biocide. (a) Number of mutants identified at each sub-culture. (b) Number of mutants identified after exposure to each biocide. (c) Identification of mutants per sub-culture by biocide.
Figure 2.
Figure 2.
Growth kinetics of selected mutant strains in comparison with SL1344. Growth kinetics were determined by measuring the OD at 600 nm of cultures every 10 min over 16 h; data shown are the averages of eight replicate cultures for each strain.
See this image and copyright information in PMC

References

    1. Piddock LJ. The crisis of no new antibiotics—what is the way forward? Lancet Infect Dis 2012; 12: 249–53. - PubMed
    1. Woodford N, Livermore DM. Infections caused by Gram-positive bacteria: a review of the global challenge. J Infect 2009; 59 Suppl 1: S4–16. - PubMed
    1. Roca I, Espinal P, Vila-Farres X et al. . The Acinetobacter baumannii oxymoron: commensal hospital dweller turned pan-drug-resistant menace. Front Microbiol 2012; 3: 148. - PMC - PubMed
    1. Tuon FF, Gortz LW, Rocha JL. Risk factors for pan-resistant Pseudomonas aeruginosa bacteremia and the adequacy of antibiotic therapy. Braz J Infect Dis 2012; 16: 351–6. - PubMed
    1. Walsh TR, Toleman MA. The emergence of pan-resistant Gram-negative pathogens merits a rapid global political response. J Antimicrob Chemother 2012; 67: 1–3. - PubMed

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