Inflammatory bowel disease (IBD) includes chronic intestinal diseases; two of which are Crohn’s disease/and Ulcerative Colitis. Escherichia coli (E.coli) is among digestive system microbial flora which is composed of the five main phylogenic group including phylogenic groups A, B1, B2, C, and E. Certain group of B2 E.coli strains possess a conserved genetic region known as pks. This region encodes a genotoxin known as Colibactin. Short term exposure of mammalian epithelial cells to the E.coli harboring/pks results in the induction of DNA damage. The aim of this study is molecular investigation of the E.coli Containing pks Region in the Biopsies of Patients with IBD. In this study we isolated E.coli pks region from 77 biopsies of the patients with IBD as well as 60 biopsies from the healthy donors. The Duplex PCR for clbB and clbN genes in PKS region was done on DNA extracted of bacteria. The PCR products with 16srRNA primer for all of E.coli with pks positive were sent for sequencing and phylogetenic tree was drawn. The results showed respectively, 49% and 2% of E.coli bacteria isolated from biopsy specimens of the patients with IBD and healthy donors contain pks gene. In terms of weight loss a significant differences was observed between the normal control group and patients with IBD (p-value= 0.001) as well as patients with UC (p-value=0.002). According to the results of this study, it seems most E.coli strains isolated to bear much related according to phylogenetic characteristics and their genetic similarity that makes them to compose a family.
 

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