An updated review of Listeria monocytogenes in the pork meat industry and its products


D. Thévenot, Unité de Microbiologie Alimentaire et Prévisionnelle, Ecole Nationale Vétérinaire de Lyon, BP 83, 69280 Marcy l’étoile, France. E-mail:


Pork meat and processed pork products have been the sources of outbreaks of listeriosis in France and in other European countries during the last decade. The aim of this review is to understand how contamination, survival and growth of Listeria monocytogenes can occur in pork meat products. This study discusses the presence of L. monocytogenes in raw pork meat, in the processing environment and in finished products. The prevalence of L. monocytogenes generally increases from the farm to the manufacturing plants and this mainly due to cross-contamination. In many cases, this pathogen is present in raw pork meat at low or moderate levels, but foods involved in listeriosis outbreaks are those in which the organism has multiplied to reach levels significantly higher than 1000 CFU g−1. In such cases, L. monocytogenes has been able to survive and/or to grow despite the hurdles encountered during the manufacturing and conservation processes. Accordingly, attention must be paid to the design of food-processing equipment and to the effectiveness of the cleaning and disinfecting procedures in factories. Finally, the production of safe pork meat products is based on the implementation of general preventive measures such as Good Hygiene Practices, Good Manufacturing and the Hazard Analysis Critical Control Point.