Molecular Characterization of Escherichia coli Isolated From Raw Sheep and Goat Milk

This study was conducted to investigate the occurrence of E. coli in raw milk of sheep and goat in Luxor Governorate, Egypt. A total of 150 samples of raw milk of sheep and goat (75 each) were collected. The results showed that 9.3% of each raw sheep and goat's milk samples were contaminated with E. coli , while, E. coli O157 could not be detected. Out of 7 E. coli strains isolated from raw sheep's milk samples, 5 strains were serotyped as O28, O166, O 27, O 128, O 26 and 2 did not give any agglutination with the used ‘O' E. coli antiserum (ONT). On the other hand, E. coli isolates of raw goat's milk were serotyped as O27, O125, O78, O152, ONT (one each) and 2 strains serotyped as O115. E. coli isolates were molecularly characterized for the presence of some virulence genes ( stx1 , stx2 and eaeA genes). PCR products analysis revealed that only one strain isolated from raw sheep milk samples ( E. coli O26) was positive for presence of stx2 only, while E. coli strains obtained from goat milk lacked both stx1 and stx2 . Also, eaeA gene was located in 85.7 and 100% of the isolated E. coli strains obtained from raw sheep and goat milk, respectively. Enterohemorrhagic E. coli (EHEC) and Enteropathogenic E. coli (EPEC) were detected in 7.14 and 85.7% of the total E. coli isolates, respectively.