Phylogenetic of Shiga Toxin-Producing Escherichia coli and a typical Enteropathogenic Escherichia coli Strains Isolated From Human andCattle in Kerman, Iran

• Main Authors: Hesam Alizade, Reza Ghanbarpour, Mojdeh Nekoubin
• Format: Article
• Language: English
• Published: Alborz University of Medical Sciences 2014-02-01
• Series: International Journal of Enteric Pathogens
• Subjects: Escherichia coli; Diarrhea; Shiga-Toxigenic Escherichia coli
• Online Access: http://enterpathog.abzums.ac.ir/PDF/ijep-2-15195.pdf
• ISSN: 2345-3362; 2322-5866

Background: Shiga toxin-producing Escherichia coli (STEC) have emerged as the important zoonotic food-borne pathogens and confirming the risk to public health. Enteropathogenic Escherichia coli (EPEC) is a major cause of children diarrhoea in developing countries. E. coli strains can be assigned to four main phylogenetic groups, A, B1, B2 and D. Objectives: The aim of the current study was to analyze the distribution of phylogenetic groups and presence of STEC and atypical EPEC pathotypes in E. coli isolated from human diarrhea and fecal samples of healthy cattle in Kerman, Iran by PCR. Materials and Methods: A total of 188 E. coli isolates were isolated from human diarrheic (94 isolates) and fecal healthy cattle (94 isolates) samples. The isolates were identified by standard bacteriological tests. The confirmed isolates were examined to detect the phylogenetic groups and a selection of virulence genes including stx1, stx2 and eae by PCR. Results: Phylotyping of isolates from diarrheic human showed that 38.29% belonged to A, 20.21% to B1, 14.89% to B2 and 26.59% to D phylo groups. The isolates of healthy cattle distributed in A (34.04%), B1 (47.88%), B2 (7.44 %) and D (10.64%) phylo-groups. Prevalence of eae gene in human diarrheic isolates was 5.32% (5 isolates), whereas none of the human diarrheic isolates were positive for stx1 and stx2 genes. Among cattle isolates 7.44% (7 isolates) were positive for stx1 gene and 5.32% (5 isolates) possessed eae gene. Of the all isolates examined, none were positive for the stx2 gene. The eae gene were positive for isolates of human diarrhea distributed in A and B2 phylo-groups and isolates possessed stx1 and eae genes from healthy cattle fell into A (4 isolates), B1 (7) and B2 (one isolate). Conclusions: The isolates of human diarrhea samples and fecal healthy cattle were distributed into different phylogenetic groups, which mostly distributed in A and B1 phylo-groups. In addition, results of this study revealed the lower prevalence of SETC and aEPEC in isolates.