Determination of virulence determinants of Escherichia coli strains isolated from patients with colorectal cancer compared to the healthy subjects

AIM: This study determined the genes encoding the binding and receiving factors of iron and microbial biofilm in E. coli strains isolated from mucosal samples of patients with colorectal cancer and inflammation of the colorectal compared to healthy people. BACKGROUND: Colorectal cancer is one of the most important malignancies in recent years. Escherichia coli is the most important infectious agents associated with colorectal cancer that has numerous virulence factors such as iron uptake and adhesion factors included in the process of inflammation and colorectal cancer. METHODS: Of the three healthy, inflammatory bowel diseases and colorectal cancer groups, 40 Escherichia coli strains isolated after confirmation by biochemical and molecular methods. After determining the isolates phylogroups, the frequency of genes was measured by PCR method. The biofilm formation of isolates was performed using Crystal Violet method. RESULTS: In the determination of the bacteria phylogroups, the colorectal cancer isolates had a maximum incidence of phylogroups B2 and A. In the analysis of fimH, papA, papC, iutA, ireA and fyuA genes, the highest frequency was observed in these two phylogroups. The presence of ireA gene in bacterial isolates from three groups showed a significant difference (P value: 0.004). There was also no significant difference in biofilm productions in Escherichia coli strains isolated from the three groups. CONCLUSION: Unlike previous studies focusing solely on Escherichia coli toxins, we found that iron absorption and adhesion factors could be effective in developing inflammatory bowel diseases and colorectal cancer. It was also determined that biofilm formation is a specific characteristic of Escherichia coli isolated from the healthy colon.