Screening of antimicrobial activities of disinfectants and cleaning agents against foodborne spoilage microbes

The antimicrobial activities of six disinfectants and cleaning agents against five food and brewery spoilage microbes were studied using the 5-5-5 suspension and a surface test simulating surface disinfection in actual use. The tests were carried out using the lowest recommended concentrations. The surface test was performed both with and without organic soil for various exposure times. In the suspension test, almost all the disinfectant and cleaning agents had adequate antimicrobial activity, except against Bacillus spores. The peroxide-based disinfectant and the isopropanol-based cleaning agent were both ineffective against Saccharomyces cerevisiae. In the surface test without soil the hypochlorite-based disinfectant was effective after an exposure of 10 min against all the microbes tested. The isopropanol-based cleaning agent was effective against all the vegetative cells tested. In the presence of soil, hypochlorite was effective against Listeria monocytogenes and Pseudomonas aeruginosa. In the test performed the lubricant which contained disinfectant had no antimicrobial activity against the surface-attached contaminants tested. P. aeruginosa was the most sensitive test organism and the Bacillus spores were the most resistant towards the agents tested.