An efficient disinfection strategy within the food industry is needed to ensure food safety and prevent the spreading of foodborne pathogens such as Salmonella Typhimurium. However, several factors affect the efficiency of disinfection treatments resulting in low level exposure of the bacterial flora facilitating survival of bacterial cells. Therefore, this study analysed the effect of repeated exposure of S. Typhimurium cells to sub-lethal benzalkonium chloride (BKC) concentrations. One single BKC exposure showed tailing of the inactivation curve indicating variation in BKC susceptibility within the initial population. Repeated exposure resulted in the enrichment of a more resistant population and variants with increased BKC resistance were isolated. Phenotypical characterization of these resistant variants showed loss of motility, reduced biofilm forming capacity and reduced cell membrane permeability pointing to modification of cell surface properties. In conclusion, repeated exposure of S. Typhimurium to sub-lethal BKC concentrations rapidly selects for resistant variants. Occurrence and persistence of such variants in food processing environments can form a risk for public health.
|Journal||Nederlands Tijdschrift voor Medische Microbiologie|
|Publication status||Published - 2014|