Prevalence of Listeria monocytogenes in meat products during 2017–2019 depending on technological factors and seasons

Microbiological examination of contamination of imported and domestic meat products with pathogenic bacteria Listeria monocytogenes depending on a meat type, technology and season was carried out during 2017–2019. In total, 2777 product samples were analyzed; the presence of this pathogen was revealed in 8.8% of products (244 positive samples). It was found that the prevalence of L. monocytogenes in meat products increased over three years of observation (2017–2019). The highest occurrence of this pathogen was found in poultry meat (on average 18.7%) followed by products from beef (13.2%). Meat products from mixed raw materials (beef and pork) accounted for 5.3% of tested samples, while in pork semi-finished products L. monocytogenes was found only in 3.2% of cases. It was noted that the technology of semi-finished products significantly affected the level of contamination of meat products with L. monocytogenes. Various technological approaches are used in the production process increasing the risk of contamination of the finished product since there is no timely data on Listeria contamination of raw materials used for production of a particular product. It has been established that a significant role in microbiological studies is played by various approaches to sample preparation of analyzed samples of meat cuts, semi-finished products in large and small pieces, as well as minced semi-finished products. Not knowing the real level of surface contamination with L. monocytogenes of carcasses, half-carcasses, semi-finished products in large pieces, manufacturers use such raw materials for the subsequent production of other types of semi-finished meat products, increasing the risk of manufacturing unsafe products with following contamination of equipment, work surfaces and other objects of the production environment. The highest occurrence of L. monocytogenes in meat products during three years of observation was found in the summer period (14.2%). The proportions of positive samples in the winter, spring and autumn months varied on average within 6.7–7.1%.