The objectives of this work were to (1) study the isolation rate of enteropathogenic Y. enterocolitica, Salmonella spp., Campylobacter spp. and L. monocytogenes in the tonsils and feces and (2) determine the number of mesophilic aerobic bacteria (MAB) and Escherichia coli in the tonsils of fattening pigs at slaughter. This is because food-borne zoonoses are infectious diseases of major health and economic significance in developed countries. They are most
often acquired through ingestion of contaminated foods but they can also be acquired directly from animals. The two most frequently reported zoonotic diseases in humans in the EU in 2007 were Campylobacter and Salmonella infections with incidences of 120 and 31 cases per 100,000 inhabitants, respectively (EFSA, 2009). The reason this study uses pig tonsils is because pigs are mostly asymptomatic carriers of Salmonella enterica, Campylobacter spp., Yersinia enterocolitica and L. monocytogenes. All these bacterial pathogens have been isolated from the intestinal
tract of pigs (Fosse et al., in press). However, pathogenic Y. enterocolitica has shown to be a more frequent inhabitant in pig tonsils (Bucher et al., 2008). In the present study, almost all (98%) fattening pigs at slaughter were carriers for at least one of these foodborne pathogens in their tonsils (76%) or were shedding them in feces (72%). Pathogenic Y. enterocolitica and L. monocytogenes were frequently isolated from tonsils while Campylobacter spp. were rarely found. The main reason was because of contamination during slaughter and this study recommends that the contamination in the slaughterhouse could be effectively reduced by changing the slaughter technique by not splitting the head and by leaving the tongue and tonsils in the oral cavity.

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