Abstract
Abstract Objective To find an association between colorectal cancer (CRC) and genotoxic Escherichia coli isolated from the human microbiota. Patients and methods A total of 150 patients (65 males and 85 females) were recruited from the surgical endoscopy unit in the Medical Research Institute Hospital, Alexandria, Egypt. They were divided into two groups: group I included 100 neoplastic patients (benign and malignant), and group II included 50 nonneoplastic patients. After DNA extraction, real-time PCR was performed to detect the presence of pks island in E. coli strains. Result The number of males (57.4%) among patients with malignant neoplastic illness was higher than the number of females (42.6%). Overall, no statistical difference was observed between the studied groups regarding sex (P=0.059). Malignant neoplastic diseases were more common in patients above 45 years. Old age in malignant patients showed a high statistical significance compared with nonmalignant patients (P≤0.001). The pks+E. coli was detected in colorectal biopsies using the clbB gene as a surrogate marker of the whole pks island. The current study demonstrated that the prevalence of pks-positive E. coli was significantly higher in patients with malignant neoplastic disease than benign neoplastic and nonneoplastic ones (P=0.002). Conclusion pks+E. coli may act as a tumor promoter for CRC and could be used as a predictive marker for CRC development. In addition, the pks+E. coli molecular identification may be of a good value in decreasing missed lesions during conventional colonoscopy.