Incidence and molecular characterization of Escherichia coli in some dairy products

Document Type : Original Article


1 Department of Food Hygiene, Faculty of Veterinary Medicine, Benha University, Egypt.

2 Animal Health Research Institute, Shebin El-Kom Branch, Egypt.

3 Food Quality Control, Minoufiya University, Egypt.


Escherichia coli is one of the foodborne pathogens associated with several cases of human sickness. The present study was undertaken to estimate the incidence of E. coli, in total of one hundred and twenty random samples of some dairy products ; Raw milk, Kareish cheese, Damietta cheese and Cream (30 samples each); were randomly collected from local markets, farmer vendors and supermarkets at different localities in Nile Delta region; Menofia Governorates, Egypt. Confirmation of the isolated E. coli serovars was performed using a series of biochemical tests, serological and PCR identification. The results revealed that 70.8% of the examined samples were E. coli positive. Twelve serogroups could be identified serologically including E.coli O26 : H11, O44 : H18, O55 : H7, O91 : H21, O111 : H2, O119 : H6, O121 : H7, O124, O127 : H6, O128 : H2, O146 : H21, O153 : H2. Finally, the results of Multiplex PCR with specific primers for detection of Stx1, Stx2 and eaeA genes, revealed that the isolates E. coli O26 : H11, O91 : H21, O127 : H6, , O111 : H2, and O153 : H2 had Stx1 and Stx2 genes while, E.coli O119 : H6, and O128 : H2 had only Stx1.Also O44 : H18, O55 : H7, O121 : H7 and O146 : H21had only Stx2. Concerning the eaeA gene, E. coli O111 and O26 isolates possessed this gene .


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