UCD Centre for Food Safety & Centre for Food-borne Zoonomics, UCD Veterinary Sciences Centre, School of Public Health, Physiotherapy & Population Science, University College Dublin, Belfield, Dublin, Ireland.
Appl Environ Microbiol. 2012 May;78(9):3087-97. doi: 10.1128/AEM.07534-11. Epub 2012 Feb 24.
Biocides play an essential role in limiting the spread of infectious disease. The food industry is dependent on these agents, and their increasing use is a matter for concern. Specifically, the emergence of bacteria demonstrating increased tolerance to biocides, coupled with the potential for the development of a phenotype of cross-resistance to clinically important antimicrobial compounds, needs to be assessed. In this study, we investigated the tolerance of a collection of susceptible and multidrug-resistant (MDR) Salmonella enterica strains to a panel of seven commercially available food-grade biocide formulations. We explored their abilities to adapt to these formulations and their active biocidal agents, i.e., triclosan, chlorhexidine, hydrogen peroxide, and benzalkonium chloride, after sequential rounds of in vitro selection. Finally, cross-tolerance of different categories of biocidal formulations, their active agents, and the potential for coselection of resistance to clinically important antibiotics were investigated. Six of seven food-grade biocide formulations were bactericidal at their recommended working concentrations. All showed a reduced activity against both surface-dried and biofilm cultures. A stable phenotype of tolerance to biocide formulations could not be selected. Upon exposure of Salmonella strains to an active biocidal compound, a high-level of tolerance was selected for a number of Salmonella serotypes. No cross-tolerance to the different biocidal agents or food-grade biocide formulations was observed. Most tolerant isolates displayed changes in their patterns of susceptibility to antimicrobial compounds. Food industry biocides are effective against planktonic Salmonella. When exposed to sublethal concentrations of individual active biocidal agents, tolerant isolates may emerge. This emergence was associated with changes in antimicrobial susceptibilities.
消毒剂在限制传染病传播方面发挥着重要作用。食品工业依赖于这些药剂，其使用的增加令人担忧。具体来说，需要评估细菌对消毒剂的耐受性增加的出现，以及对临床重要抗菌化合物产生交叉耐药表型的潜力。在这项研究中，我们研究了一组易感性和多药耐药 (MDR) 沙门氏菌菌株对七种市售食品级消毒剂配方的耐受性。我们探讨了它们适应这些配方及其有效消毒剂（三氯生、洗必泰、过氧化氢和苯扎氯铵）的能力，即在体外选择的连续轮次后。最后，研究了不同类别的消毒剂配方、其有效成分之间的交叉耐受性以及对临床重要抗生素耐药性共选择的可能性。七种食品级消毒剂配方中的六种在其建议的工作浓度下具有杀菌作用。所有配方对表面干燥和生物膜培养物的活性均降低。不能选择对消毒剂配方的稳定耐受性表型。当沙门氏菌菌株暴露于有效消毒剂化合物时，许多沙门氏菌血清型对高水平的消毒剂化合物表现出耐受性。未观察到对不同消毒剂化合物或食品级消毒剂配方的交叉耐受性。大多数耐受分离株对抗菌化合物的敏感性模式发生了变化。食品工业消毒剂对浮游生物沙门氏菌有效。当暴露于亚致死浓度的单一有效消毒剂化合物时，可能会出现耐受分离株。这种出现与抗微生物敏感性的变化有关。
