ميزان شيوع گونه هاي يرسينيا در گوشت قرمز و مرغ عرضه شده در جنوب تهران

Prevalence of Yersinia spp. in red meat and chicken marketed in southern Tehran

Background and Aim Yersinia is an important water- and food-borne bacterium causing gastroenteritis in humans. Material and Methods: From December 2002 to July 2003, a total of 250 samples -including 158 meat samples and 92 chicken samples- were taken from butcheries and poultry shops operating under the supervision of Tehran University of Medical Sciences. We used a two-step enrichment procedure: phosphate buffer saline was used as primary enrichment within 3 weeks in refrigerator (cold enrichment). Then we applied KOH treatment as secondary enrichment and performed cultures on CIN agar. Results: In this study, 44.4% of all samples showed Yersinia contamination. The prevalence of Yersinia was 29.1% in meat and 70.7% in poultry. Of the 155 Yersinia isolates, 53 (34.2%) were identified as Y. enter ocolitica, 47(30.3%) as Y. intermedia, 42 (27%) as Y. fredriksenii and one (0,6%) as Y. kristensenii. Biotyping of Y. enterocolitica showed that 51 strains (39.7%) corresponded to biotype 1A, 13 strains (24.6%) to biotype IB, one (1.8%) to biotype 2, three (5,7%) to biotype 3 and one (1.8%) to biotype 4. Fourteen strains (26.4%) could not be classified. Conclusion: The high prevalence rates in meat and poultry implies that these products could be widely contaminated with Yersinia, thus serving as important vehicles for transmission to humans.