Isolation and identification of non-O157 Shiga toxin Escherichia coli from humans and calves using conventional and molecular technique

This study was done to isolate and identify the non-O157 STEC in Karbala Province, Iraq. The results showed a new serotype of this bacteria (IQ1) showing different clinical symptoms such as fever, dehydration, colic, fatigue, nausea, abdominal cramps, nerves signs, renal failure, hemolytic uremic syndrome (HUS), hemolytic colitis, bloody to purulent diarrhea in human and animals infected by this pathogen. A total of 400 samples were collected from children’s stool and calves’ fecal samples, then cultured on different mediums for isolation. The biochemical tests were used for identification such as oxidase, citrate, urease and Voges–Proskauer, catalase, Methyl red, and indole tests. The PCR technique was used for the confirmation of the non-O157 STEC. The results showed from 197 calves’ samples 25 (12.69%) and from 203 children’s samples, 20 (9.85%) gave positive results. The antibiotic susceptibility test was used to know which antibiotic has the best results and the results revealed Ciprofloxacin with the best zone of inhibition compared with other antibiotics.