Study of the Sensitivity of Microorganisms to Biocides
Department of Food and Nutrition, Department of Nutrition and Quality Assessment of Food, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava
Keywords: chlorine dioxide, hydrogen peroxide, sodium hypochlorite, gram-negative bacteria, gram-positive bacteria
The paper is devoted to the study of the resistance of Salmonella enterica subsp. enterica serovar typhimurium, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Bacillus subtilis to biocidal substances, such as sodium hypochlorite, chlorine dioxide, and hydrogen peroxide containing silver. The interdependence between this resistance and a reduced sensitivity of these bacteria to the selected biocides was studied. The results can be summarized as follows: passaging in media with increasing concentrations of selected biocides can yield a culture capable of growing at as high concentrations of biocides as 2200 µg mL1 NaClO, which represents an 800-fold increase over the original MIC (minimum inhibitory concentration). It follows from the results, however, that there is no single model describing the relationship between the resistance and the reduced susceptibility to biocides. The results depend on the nature of the biocide, as well as on the conditions under which they are obtained.
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