PREVALENCE AND SURVIVAL OF ENTEROPATHOGENIC ESCHERICHIA COLI (EEC) IN YOGHURT

30 yoghurt samples were collected randomly from Assiut city markets, and examined for presence of enteropathogenic E.coli (EEC). E.coli could be isolated from 46.6% of the 7 examined yoghurt samples. The highest frequency distribution of E.coli (23.3%) lies within the range of 10-100/g. Nine out of 14 E.coli strains isolated from yoghurt samples (64.3%) were serotypes of EEC. They were serotyped as 026/86, 025/Kll, 044/ B74, 0111/B, 0124/E17, 0125/B 15 and 0126/B16. Survival of EEC (Serotype 0125/815) in yoghurt kept at 5+1°C was also studied. EEC survived until the end of the tenth day of storage at a population of less than 10 cells/g. The pH value of yoghurt decreased from 6.5 to 4.5 by the end of preparation and reached to 3.9 at the end of refrigerated storage.