Phylogenetic evaluation of Escherichia coli isolated from cases of bacillus diarrhea

Escherichia coli )E. coli) is the normal flora of the gastrointestinal tract of humans and animals, although most of the strains are known not to be pathogenic. Pathogenic strains of E. coli can cause a wide variety of diseases, including urinary tract infection, intestinal and extra-intestinal diseases, as well as problems in the respiratory system. In fact, 80-90 % of urinary tract infections are attributed to E. coli bacteria along with different phylogenetic groups of these bacteria. The aim of this study was to determine phylogenetic groups of E. coli isolates from fecal samples of calves affected with Bacillus in the Moghan region, northwest of Iran. Samples were taken from 60 calves (1 to 30 days old) with common basil diarrhea in a dairy farm located in the Moghan region in the northwest of Iran in 2017. Samples were cultured in E. coli culture media. Among isolated bacteria, 50 samples (83.33%) were positive for E. coli bacteria. Then the samples were coded and prepared for PCR. The phylogenetic background of the isolates was determined according to the presence of the chuA, yjaA, and TspE4.C2 markers in E. coli bacteria. The results showed that among 50 isolates, 31 were B2 group (62%), 8 were D group (16%), 3 were B1 group (6%), 1 was A group (2%), and remaining cases were 7 (14%). Obtained results clearly demonstrated that the most frequent phylogenetic group of E. coli was B2, whereas group A was the least one in the Moghan region.