Identification of Escherichia coli O157: H7 from Slaughtered Beef in Mashhad Using Biochemical and Molecular Methods

Background and Aims: Escherichia coli O157:H7 is one of the main causes of transmitted diseases by food, including meat and meat products. The purpose of this study was to investigate the prevalence of E. coli O157:H7 contamination in Mashhad with the detection of rfbE gene. Materials and Methods: For this study, 148 slaughtered beef samples from Mashhad (spring to winter, 2018) were randomly collected and transferred to the laboratory. The identification of E. coli O157:H7 was performed by biochemical methods and rfbE gene was detected by PCR colony method. Results & Discussion: Based on biochemical tests, E. coli O157:H7 was isolated in 7 (4.73%) samples of slaughtered beef and after PCR colony; only 2 (1.35%) of these 7 samples were approved. According to the results of this study, it can be concluded that beef can be considered as a major reservoir for E. coli O157:H7 and there is a potential for transmission of this pathogen to humans through the consumption of beef and its products. Also, the specific primers of rfbE gene were able to differentiate the E. coli O157:H7 colonies from other cultured colonies on the culture medium during the PCR process. The present research was performed for the first time in the city of Mashhad.