Serotypes and virulence profiles of non-o157 shiga toxin producing e. coli isolated from beef, chicken meat and its products

الملخص EN

This study was conducted on 300 samples (150 beef and 150 chicken meat) collected from Menofia, Cairo and El-Kalyobia governorates for detection of STEC.

STEC were isolated from beef and chicken meat on Trypticase Soya Broth and Sorbitol MacConkey agar supplemented with cefixime and tellurite supplements and were biochemically identified.

Further identifications were performed including Vero cells cytotoxicity assay and PCR technique for specific VT1/VT2 and eae genes.

Vero cells cytotoxicity assay was performed on 130 suspected colonies obtained from 300 samples collected from raw meat and meat products (150) and raw chicken and products (150) revealed that 56 of E.

coli isolates were STEC.

By PCR, 56 (100%) of the 56 strains were confirmed to be STEC.

In comparison to Vero cells cytotoxicity, the sensitivity of PCR were 100%.

The most common serogroups of STEC in samples were O111, O26, O103, O119, O128, O86, O45, O146, O119 and O121.

E.coli O111, O26, O103, O91, O86 and O119 that proved to have Stx1 and Stx2 genes.

E.coli O128 and O121 had only Stx1, while E.coli O146 had only Stx2.Concerning the eae gene responsible for the attaching and effacing lesions, E.

coli O111 and O26 isolates proved to possess such gene.

In conclusion raw beef, raw chicken and products constitute an important reservoir of STEC infection to man and it was declared that PCR technique is the most rapid, sensitive and efficient approach for detection of STEC in beef and chicken products.