INTRODUCTION INTO JAPAN OF PATHOGENIC YERSINIA THROUGH IMPORTED PORK,BEEF AND FOWL

Yersinia was isolated from imported raw meat and fowl products by HeLa cell treatment and conventional KOH-treatment, to obtain information on the origin of pathogenic Yersinia in Japan. Forty-one strains of Ye rsinia enterocolitica and one strain of Yersinia pseudotuberculosis, s erotype 4b were isolated from 38 (3.0%) of 1278 samples of pork, two ( 0.3%) of 612 samples of beef and two (0.3%) of 615 samples of chicken. Y. enterocolitica isolates belonged to B:4/O:3 (biotype/serotype, 15 strains), B:3/O:3 (two strains) and B:3 variant/O:3 (17 strains) and B :3/O:5.27 (seven strains). The B:4/O:3 which is globally prevalent amo ng humans and animals was isolated from pork samples from Denmark and the US and from beef samples from Australia, the B:3/O:3 from pork sam ples from Canada, the B:3 variantiO:3 from pork samples from Taiwan an d from chicken samples from Thailand, the B:3/O:5.27 from pork samples from the US and Taiwan and Y. pseudotuberculosis, serotype 4b from po rk samples from Canada. These findings suggest that pathogenic Y. ente rocolitica strains can be introduced into Japan by the import of pork from pig producing countries. The HeLa cell treatment was found to be superior to the conventional method. (C) 1997 Elsevier Science B.V.