Detection of shiga-like toxigenic Escherichia coli from raw milk cheeses produced in Kerman-Iran

The Shiga-like toxin-producing escherichia coli (STEC) is the most important group of food-borne pathogens that emerged recently. These bacteria can cause severe health problems in humans like diarrhea, hemorrhagic colitis and hemolytic uraemic syndrome which have become a serious health problem in various countries. Cattle are thought to be a reservoir for e. coli STEC, and many foodborne diseases have been associated with the consumption of minced beef, beefburgers and raw milk. Although some data suggest that STEC are not prevalent within dairy products, the aim of this work was to assess the prevalence of e. coli O157 and non-O157 STEC in raw milk cheeses produced in the Southern part of Iran (Kerman province). For this purpose, 125 samples of soft and semi-soft cheeses made with raw cow milk were analysed with multiplex-PCR method for the presence of STEC. The use of consensus primers detected stx genes in 6.4% of the samples, but STEC strains could be isolated in only five of them (4%). Just one sample was found to be contaminated with e. coli O157. Our results suggest that in our area study raw milk cheeses could be considered a risk for food born STEC contamination.