Background: During the last decades, wild boar populations have increased in Europe and spread over the entire continent. The population densities of wild boars in Switzerland are among the highest reported in Western Europe. High wild boar densities and increasing popularity of outdoor ranging of fattening pigs may intensify the risk of contacts between wild boars and domestic pigs and, therefore, the transmission of microorganisms and parasites. With this background and with the background of increasing per capita consumption of wild boar meat and the high per capita consumption of pork, knowledge of the situation of the food-borne pathogens circulating in the wildlife population is an important public health issue. Methods: In this study, tonsils of 153 wild boars hunted in the Western part of Switzerland were enriched overnight in TSB and screened on the presence of L. monocytogenes using VIDAS®. Positive samples were cultured on two selective agar media. Presumptive positive colonies were biochemically identified. L. monocytogens strains were further characterized by serotyping and genotyping methods. Results: L. monocytogenes are food-borne pathogens that are distributed in a wide variety of environments. Human infection may lead to a serious and potentially life threatening illness known as listeriosis. Reports from the USA show that L. monocytogenes infections are responsible for the highest hospitalization rates (91%) amongst known food-borne pathogens. L. monocytogenes were isolated from tonsils of twenty-six (17%) animals. Of the 26 isolates, 45% were of serotype 4b, 38% were of serotype 1/2a and 17% were of serotype 1/2b. Epidemiological data from different countries shows that the majority of human infection outbreaks are primarily associated with three L. monocytogenes serotypes (1/2a, 1/2b and 4b), despite the fact that there are 13 serotypes potentially capable of infecting humans. Further genotyping results of the isolated strains will be presented. Conclusion: This study shows, that tonsils of wild boars are not only a reservoir for Yersinia enterocolitica and Yersinia pseudotuberculosis, but also for Listeria monocytogenes. This has mainly to be considered by the hunters, who may be handling carcasses under minimal hygiene conditions. Moreover, outside rearing of domestic pigs and close contact to wild boars may increase the risk of transmission. Abstracts for SupplementInternational Journal of Infectious DiseasesVol. 14Preview Full-Text PDF Open Archive