Virulence Factors of Mucosa-associated Escherichia coli Isolates in Colorectal Cancer in Mansoura, Egypt

Background: Colorectal cancer (CRC) is one of the most commonly identified tumors globally. Emerging findings suggest that E. coli may be implicated in colorectal carcinogenesis and tumor progression, with various virulence determinants potentially promoting inflammation and disease advancement. Objective: This study aims to examine the phylogenetic groups, hemolytic activity, and presence of cyclomodulins in mucosa-associated E. coli isolated from individuals with CRN. Methodology: In this cross-sectional study, 81 samples were collected during colonoscopy in the Gastrointestinal Center in Mansoura, Egypt. E. coli was isolated from colorectal biopsies and defined by biochemical and molecular methods. Phylogroups, cyclomodulin genes (clbB, cnf1 genes), were identified by PCR. Results: Sixty-three mucosa-associated E. coli were detected from colorectal biopsies of 21 CRC 7 CRA and 35 control subjects. B2 and A were the most common phylogroup in CRN and control subjects, respectively. Hemolytic E. coli Isolates were significantly elevated in CRN isolates than in isolates from control subjects (P <0.05). Detection of clbB and or cnf1 genes was higher in mucosa-associated CRN E. coli than in the control subjects. Conclusions: In conclusion, Phylogroup B2 is the most common phylogroup in CRN. ClbB gene positive mucosa-associated E. coli was elevated in CRN than in control subjects. Finally, our results support the hemolytic activity in E. coli strains of CRC.