OCCURRENCE OF YERSINIA ENTEROCOLITICA AND LISTERIA MONOCYTOGENES IN FRESH WATER FISH

Fifty samples of several types of fresh water fish purchased at fish markets in Assiut were investigated for the presence of Y. enterocolit ica and L. monocytogenes. Ten strains identified as Y. enterocolitica were isolated from both flesh and intestinal contents of all examined fish species. Seven Y. enterocolitica strains were of biotype 1, two were of biotype 4 and one was of biotype 2. Clarias lazera, Bagrus bayad and Schilbe mystus flesh revealed the presence of Y. enterocolit ica in 10%, 11.11% and 20% of the examined specimens respectively. Further, Y. enterocolitica were recovered from 5.88%, 20%, 11.11%, 11.11% and 40% of the intestinal contents of Tilapia nilotica, Clarias lazera, Synodontis schall, Bagrus bayad and Schilbe mystus. L. Monocy togenes could be detected in 40% of the intestinal contents of Schilbe mystus. The public health implication of the presence of Y. enterocolit ica and L. monocytogenes in fish was discussed.