Shiga toxin-producing Escherichia coli O157 in feedlot cattle and Norwegian rats from a large-scale farm

A total of 365 faecal samples from different categories of cattle, 12 sampl es of untreated slurry, 50 samples of fresh droppings of fetal domestic pig eons, 20 samples of fresh droppings of domestic sparrows and stool samples of 19 synanthropic rodents were examined for the presence of Escherichia co li by broth enrichment culture and a subsequent immunomagnetic separation. Escherichia coli O157 was found in 72 (20%) bovine samples, sis (500%) samp les of untreated slurry and four (40%) of 10 rats (Rattus norvegicus). Sign ificant differences were found in the E. coli O157 shedding frequency betwe en different age categories of bulls. Genes stx2 and eaeA were detected in all isolates, and the stx1 gene in all but 10 isolates.