Investigation of frequency stx۱, stx۲, and sta genes in the isolates of Escherichia coli from Holstein Friesian calves, infected with coli bacillosis in Ilam province

Escherichia coli is a natural part of the human intestinal flora of mammals and birds. Escherichia coli is generally an opportunistic pathogen that seeks to suppress the host immune system and the occurrence of the primary viral and microbial diseases of the respiratory tract occurs secondarily. E. coli in humans and mammals is often responsible for gastrointestinal infections. Generalized bacillosis occurs at different ages, but infection is more common in younger calves and is more common in children under three days of age .Given that pathogenic E. coli species play an important role in food poisoning and livestock products can be a good sources that can cause pathogenicity in humans.Measures should be taken to prevent human infection with this bacterium. This study aimed at molecular isolation of STX۱, STX۲ and STA genes in E. coli in calves with generalized bacillosis using culture; Multiple PCR was performed in Ilam city.For this study, ۱۰۰ Escherichia coli isolates were collected from calves with generalized bacillosis from farms in Ilam city. Samples in sterile containers were transferred to the microbiology laboratory in Ilam University as soon as possible.Initial identification of isolates was performed using gram staining and growth in Mac conky agar medium. Additional biochemical tests were performed to confirm E. coli isolates. First, the isolates were cultured on EMB jellies and overnight at ۳۷ ° C. They were then incubated with lactose-positive colonies containing metallic polishes for final identification on TSI media MRVP, SIM and Simon citrate and urea and after biochemical approval, the desired isolates in TSB medium. According to the results obtained from ۱۰۰ isolated isolates and according to molecular tests and polymerase chain reaction in total, ۲۶% had the STX۱ gene, ۱۰% had the STX۲ gene, and ۳۳% had the STE gene .

کلیدواژه ها:

E.coli ، Holstein friesian ، stx۱ ، stx۲ ، and sta genes