Sampling the processing environment for listeria

Abstract

This chapter describes in detail the procedures used when sampling for Listeria in food processing environments. Sampling of food contact surfaces, non-food contact surfaces, and liquids such as drain effl uents are addressed. Sponge stick swabs are considered advantageous for surface sampling and tips regarding their application are given. Liquids are collected using sterile dippers and the procedure for their correct use is described. Advice on places to sample, the best time for sampling and the frequency of sampling are also given. Such details help hygienists/microbiologists to be successful in their attempts to isolate strains of Listeria , even if such bacteria are well attached to surfaces or located in niches that are diffi cult to reach.