Inactivation of Listeria monocytogenes, Escherichia coii O157:H7, and Salmonella Typhimurium with compounds available in households

Abstract

Solutions of selected household products were tested for their effectiveness against Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium. Hydrogen peroxide (1.5 and 3%), vinegar (2.5 and 5% acetic acid), baking soda (11, 33, and 50% sodium bicarbonate), household bleach (0.0314, 0.0933, and 0.670% sodium hypochlorite), 5% acetic acid (prepared from glacial acetic acid), and 5% citric acid solutions were tested against the three pathogens individually (fivestrain composites of each, 108 CFU/ml) by using a modified AOAC International suspension test at initial temperatures of 25 and 55°C for 1 and 10 min. All bleach solutions (pH 8.36 to 10.14) produced a >5-log reduction of all pathogens tested after 1 min at 25°C, whereas all baking soda solutions (pH 7.32 to 7.55) were ineffective ( 5-log reduction of both Salmonella Typhimurium and E. coli O157:H7, whereas undiluted vinegar (pH 2.58) had a similar effect only against Salmonella Typhimurium. Compared with 1 min at 25°C, greater reductions of L. monocytogenes (P<0.05) were obtained with all organic acid and hydrogen peroxide treatments after 10 min at an initial temperature of 55°C. The efficacies of household compounds against all tested pathogens decreased in the following order: 0.0314% sodium hypochlorite > 3% hydrogen peroxide > undiluted vinegar and 5% acetic acid > 5% citric acid > baking soda (50% sodium bicarbonate). The sensitivity of the tested pathogens to all tested household compounds followed the sequence of Salmonella Typhimurium > E. coli O157: H7 > L. monocytogenes.