Incidence of yersinia enterocolitica in some food and environmental samples in Saudi Arabia

Alkali treatment, after enrichment in an appropriate selective medium, was used to isolate Yersinia enteroco/itica from food and environmental samples in Riyadh, Saudi Arabia. A total of 33 isolates were obtained from 106 specimens of sewage water, irrigation water and chicken cecal contents, whereas no isolates were obtained from 110 samples of milk, chocolate milk, drinking water and rain water. All of the known Y. enteroco/itica biotypes were represented at rates of approximately 51,21,12,12 and 3% for biotypes 2,4,3,1 and 5 respectively. Nineteen of the isolates (58%) were virulent as estimated by the known virulence criteria of this species