Investigating the Contamination of E.coil O157:H7 in Processed Meat Products Produced in Two Factories at Shiraz and Tehran

E.coil O157:H7 is one of the main factors leading to food toxicity anddiseases such as diarrhea, bleeding coliris, uremic hemolytic syndrome, thrombocytopenicpurpura and even death in man. Enrichment was made in two stages by lactose broth and selenite cystein and then cross over was made on chrome agar E.coil O157:H7 media. The purplecolor colonies represent the presence of this microorganism. It is worth to mention that the chrome agar specific culture media acts selectively and dose not have the problems of mechanical agar sorbitol culture media. The positive separated cases underwent confirmation tests detection by multiplex PCR. In this method, STX1 and STX2 genes were separated. The products consisted of premium hamburgers (after 3 months of production) and ordinary hamburgers (after 48 hours, 3 months and 6 months of production). The findings obtained by m-PCR diagnostic test and culture on chrome agar indicated high contamination of tested meat products, that might be due to various reasons namely failure to follow up the health procedure and mechanism and the addition of illegal additive to the products. We suggest strict microbiological tests to be carried out and E.coil O157:H7 tests become mandatory in meat production plants.