Dokaz “shiga-like” toksigene E. coli u svježim sirevima proizvedenim u Kermanu, 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 contaminationEscherichia coli koja proizvodi “shiga-like” toksin (engl. shiga-toxin producing E. coli; STEC) pripada skupini najvažnijih bakterija trovača hranom te odnedavno ima sve veće značenje. Ta bakterija može uzrokovati teške poremećaje u ljudi, kao što su proljev, hemoragijski kolitis i sindrom hemolitične uremije, koji su postali ozbiljni zdravstveni problemi u različitim zemljama. Goveda se smatraju rezervoarom za E. coli STEC te su mnoge bolesti vezane uz uzimanje mljevene govedine, usitnjena oblikovana goveđeg mesa i sirova mlijeka. Premda neki podatci govore da se STEC ne nalazi u većoj mjeri u mliječnim proizvodima, svrha je ovoga rada procijeniti prevalenciju E. coli O157 i non-O157 STEC u svježim sirevima proizvedenima u južnom dijelu Irana, u pokrajini Kerman. U tu je svrhu 125 uzoraka mekanih i polutvrdih sireva proizvedenih od sirova kravljeg mlijeka bilo analizirano multipleks PCR-om na prisutnost STEC-a. Uporabom sukladnih početnica dokazani su geni stx u 6,4% uzoraka, ali su sojevi STEC bili izdvojeni samo u pet od njih (4%). Samo jedan uzorak bio je kontaminiran bakterijom E. coli O157. Rezultati upućuju na zaključak da se u istraživanom području sirevi od svježeg kravljeg mlijeka mogu smatrati rizičnim za pojavu STEC-a