A comparison of the bactericidal efficacy of 18 disinfectants used in the food industry against Escherichia coli O157 : H7 and Pseudomonas aeruginosaat 10 and 20 degrees C

A number of proprietary disinfectant products (18) used in the food industr y were tested for their bactericidal efficacy against Pseudomonas aeruginos a and Escherichia coli O157:H7 at 20 and 10 degrees C according to the BS E N 1276 (1997) quantitative suspension test for the evaluation of bactericid al activity of chemical disinfectants and antiseptics used in food, industr ial, domestic and institutional areas. At 20 degrees C, 13 products passed at their in-use concentration (under clean and dirty conditions) against Ps . aeruginosa and 15 passed against E. coli O157:H7. The number of products passing the test at 10 degrees C was 11 and 14 for Ps. aeruginosa and E. co li O157:H7, respectively. The products exhibiting reduced efficacy at the l ower temperature were amphoterics and quaternary ammonium compounds althoug h some of these types of products were effective at both temperatures. Prod ucts that passed against Ps. aeruginosa generally also passed against E. co li O157:H7. Taking all the results together, only 11 of the total of 18 pro ducts achieved a pass result under all the parameters tested. This work dem onstrates the need for final verification of disinfectant efficacy by under taking field trials in the food-processing environment in which the product is intended for use.