Inhibition of Yersinia enterocolitica serotype O3 by natural microflora of pork.

Yersinia enterocolitica serotype O3 did not grow but did survive in inoculated raw ground pork kept at 6 and 25 degrees C. The antagonistic effect of microbial flora, especially Hafnia alvei and environmental Yersinia organisms, on the growth of Y. enterocolitica serotype O3 in raw ground pork was evident. These results were supported by evidence of the inhibition of growth of Y. enterocolitica serotype O3 by Enterobacteriaceae, especially H. alvei and environmental Yersinia organisms, in mixed cultures at 6 and 25 degrees C. We suggest that naturally contaminated pork is a source of human infection, since Y. enterocolitica serotype O3 was capable of surviving in the raw pork for a long time.