Detection of virulence genes of enterohaemorrhagic E. Coli isolated from some meat products by polymerase chain reaction

Document Type : Original Article

Authors

1 Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Benha University

2 Animal Health Research “Shebin El- Kom branch”

Abstract

A grand total of 105 meat product samples of minced meat, sausage and luncheon (35 of each) were
duplicated bacteriologically examined to detect Enterohaemorrhagic E.coli prevalence and some virulence
genes. One replicate was processed for EHEC non O157 by using conventional method for isolation and
identification of E.coli and the other for E.coli O157:H7, then serological typing and PCR technique for
specific stx1, stx2, cvcC and hlyA genes from 6 random samples were applied. E.coli was isolated from 12
samples (34%), 9 samples (25.7%) and 11 samples (31%) of the examined minced meat, sausage and
luncheon, respectively. The isolated serotypes of EHEC were O26 (5 strains) 15.6%, O111 (3 strains) 9.4%
and O157 (3 strains) 17.6%. The incidence of EHEC O26 were (2 strains) 5.7%, (2 strains) 5.7%, (1strain)
2.85%, incidence of O157:H7 were (2 strain) 5.7%, (1 strain) 2.85%, 0% in minced meat, sausage and
luncheon, respectively. The incidence of O111 was 2.85% from each the type meat products. PCR results
indicated that stx2 and cvaC virulence genes were detected in the same studied strain (O157:H7 from minced
meat sample), while stx1 and hIyA genes were not detected. Accordingly, meat products may constitute an
important reservoir for EHEC and PCR technique is the most sensitive and efficient approach for detection
of EHEC genes.

Keywords