شناسايي باكتري هاي E. coli توليدكننده توكسين مقاوم به حرارت ST، حساس به حرارت LT و شبه شيگلاييSLT در مدفوع بيماران مبتلا به اسهال به روش PCR

PCR detection of heat-stable, heat-labile, and shiga-like toxin genes in escherichia coli

Protein exotoxins of some strains of escherchia coli (enteretoxigenic) play an important role in pathogenesis of diarrhea diseases in human and domestic animals. These strains produce heat-labile enterotoxin (LT), heat-stable enterotoxin (ST) or both. The strains of E.coli producing shiga-like toxins (SLTEC) cause a large amount of human diseases like non-bloody diarrhea as well as hemorrhagic colitis with subsequent development of hemolytic uremic syndrome or thrombotic thrombocytopenic purpura. Strains of E.coli that cause diseases are difficult to recognize from those that are part of the normal intestinal flora in human and animals. In this study we used special primers for amplifying toxin genes. The toxin producer E.coli were identified by presence of certain PCR products on gels. Thirty one sample were tested. The results show that only one sample was toxigenic E.coli with both LT and ST genes. The findings show that using PCR is more reliable to detect toxin gences in strains of ETEC and SLTEC. This method is very specific, simple and rapid.