Phenotypic changes contributing to Enterobacter gergoviae biocide resistance.
Enterobacter gergoviae is a recurrent contaminant of cosmetic and hygiene products. To understand how this bacterium adapts to biocides, we studied Ent. gergoviae CIP 76.01 and its triclosan and Methylisothiazolinone-chloromethylisothiazolinone (MIT-CMIT) tolerant isogenic mutants. They were compared with others also isolated from contaminated cosmetics. Phenotypic differences were noted and these included changes in the bacterial envelope and flagella along with differences in motility, and biofilm growth rates. Triclosan and MIT-CMIT derivatives expressed flagella and other MIT-CMIT derivatives exhibited some external appendages. Those bacteria expressing a high-level minimal inhibitory concentration to MIT-CMIT, expressed a strong biofilm formation. No differential phenotypes were noted for carbon source utilisation. Enterobacter gergoviae demonstrated a diverse response to both of these preservatives contained in cosmetic preparations, depending on their concentrations. Interestingly, this adaptive response is associated with modifications of filament structure-related proteins contributing to increase the organism motility and the production of biofilm.


CONCLUSIONS
Recurrent contaminations of cosmetics products by Ent. gergoviae, needed a better understanding concerning the bacterial adaptation to preservative agents, with particular concern to triclosan and MIT-CMIT. We demonstrated that bacteria response is associated to various mechanisms represented by expression of external appendages (pili or fimbriae) that control cell motility and biofilm formation and evolving as the concentration of biocides adaptation increased. Such mechanisms which are not chemical specific can also promote a cross-resistance to other biocidal agents. The characterization of Ent. gergoviae adaptability to biocides allows industry to adjust the ranges of concentrations and composition of preservatives in formula.
UMR-MD1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France.
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Périamé
UMR-MD1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France.|Laboratoire Information Génomique et Structurale (IGS), UMR 7256 (IMM FR 3479) CNRS Aix-Marseille Université, Marseille, France.
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Philippe
UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin 4, Ireland.
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Condell
UCD-Centre for Food Safety, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin 4, Ireland.
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Fanning
UMR-MD1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France.
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Pagès
UMR-MD1, Aix-Marseille Université, IRBA, Transporteurs Membranaires, Chimiorésistance et Drug Design, Marseille, France.
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Davin-Regli
D018441:Biofilms / Q000187:drug effects; D003358:Cosmetics; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000502:physiology*; D004754:Enterobacter / Q000187:drug effects* / Q000235:genetics; D010861:Fimbriae, Bacterial; D005407:Flagella / Q000502:physiology; D008826:Microbial Sensitivity Tests; D011310:Preservatives, Pharmaceutical / Q000494:pharmacology*; D013844:Thiazoles / Q000494:pharmacology*; D014260:Triclosan / Q000494:pharmacology*
D003358:Cosmetics; D004202:Disinfectants; D011310:Preservatives, Pharmaceutical; D013844:Thiazoles; C011506:2-methyl-4-isothiazolin-3-one; D014260:Triclosan
Enterobacter gergoviae; biofilm; cosmetics; fimbriae; flagellum; preservatives; triclosan