PREVALENCE OF LISTERIA-MONOCYTOGENES, CAMPYLOBACTER-JEJUNI, YERSINIA-ENTEROCOLITICA, AND SALMONELLA IN BULK TANK MILK - RISK-FACTORS AND RISK OF HUMAN EXPOSURE

Milk samples (n = 292) from farm bulk tanks were analyzed for selected bacteria. Frequency of bacterial isolation was Listeria monocytogenes 12 (4.1%), Campylobacter jejuni 36 (12.3%), Yersinia enterocolitica 44 (15.1%), and Salmonella 26 (8.9%). The presence of one or more selected bacteria was not associated with grade classification of dairy, barn type, milking hygiene, reported incidence of clinical mastitis among cows, or the number of cows on the farm. Consumption of raw bulk milk was reported by 68/195 (34.9%) dairy producers, and of bulk tanks from which raw milk was consumed, 17/68 (25%) were contaminated with one or more species of pathogenic bacteria.