presence of escherichia coli o157:h7 in dairy farms located in najaf, baghdad, kirkuk, and erbil, iraq

It has been approved that one of the most dangerous foodborne pathogenic bacteria is e. coli o157:h7, which is responsible for several infection and death cases worldwide. it is well documented that in the developing countries e. coli o157:h7 is considered the main causative pathogen of human gastrointestinal infections. therefore, the current research was aimed to evaluate the prevalence of e. coli o157:h7 in dairy cattle's milk using a rapid method, in iraq (najaf, baghdad, kirkuk, and erbil). over a period of 6 months (during hot months) samples were obtained and investigated by culturing on selective media (ct-smac). the multiplex pcr (m-pcr) also used for milk sample direct investigation. using biochemical tests the recorded data showed that, 2 recognized isolates were e. coli, while the recorded data obtained from m-pcr assay revealed that none of the isolated e. coli was toxigenic e.coli o157:h7. the results of m-pcr on the milk samples revealed that 45 milk samples contained at least one of the following genes: o157, h7, stx1, stx2 genes. also the results of the m-pcr revealed that 2 samples (raw milk) were toxigenic o157:h7 positive. in conclusion, to the best of authors' knowledge, this investigation was the first report on the prevalence of e. coli o157:h7 in the raw milk samples in iraq. the results showed that the proportion of contaminated milk samples contaminated with e. coli o157:h7 identified in the current survey were similar to that the results of the previously published research from different dairy products across different countries in the middle east region.