Listeria monocytogenes isolated in ready-to-eat food in South bačka region of Vojvodina province, Serbia

Abstract

Listeria monocytogenes is pathogenic bacterium that can contaminate food products during and after processing. As ready-to-eat food does not undergo any treatment to ensure its safety before consumption, the risk of foodborne disease must be considered if this pathogen is present in the food. As diseases caused by contaminated food are an important public health problem today, the aim of this study was to determine the prevalence of Listeria monocytogenes in different ready-to-eat food products. In the seven-month period from June 1 to December 31, 2011, a total of 1 380 food samples were examined in the Division of Sanitary Bacteriology, Center for Microbiology, Institute of Public Health of Vojvodina in Novi Sad. A total of 912 samples were analyzed for the presence of Listeria monocytogenes according to ISO 11290-2. The identity of suspected Listeria monocytogenes was confirmed using the VITEK 2 Compact system (BioMerieux, France). Out of 912 samples, Listeria monocytogenes was detected in 18 (1.97%). Listeria monocytogenes was mostly found in cooked meals (in 6 samples out of 18), sandwiches (4 samples) and frozen food, such as ice-cream and frozen vegetables (4 samples). It was also found in tofu bread spreads (2 samples), cream cheese (1 sample) and cakes (1 sample). The presence of Listeria monocytogenes in some ready-to-eat food could present a public health hazard, particularly to the high-risk population group, because of the high mortality rate associated with listeriosis and the widespread nature of the organism. Monitoring of listeriosis is essential to prevent foodborne outbreaks, and in assessing human health risk in ready-to-eat foods.