Study the Toxic Effect of Colibactin Produced by Polyketide Synthase Escherichia coli

Abstract

Polyketide synthase island, also known as pks island, is a gene cluster that is present in Escherichia coli and this island is responsible for the creation of the genotoxin colibactin. Additionally, it has the capability to generate severe DNA distortions and damage, ultimately play a role in the progression of cancer. This study is aimed to investigate the genotoxic effect of colibactin toxin produced by pks+ E.coli isolates. One hundred and twenty E. coli isolates were obtained from various clinical sources and analyzed. A total of 63 samples tested positive for E. coli, representing 52.5% of the overall amount. The phenotypic and genotypic characteristics of the colibactin toxin detected by subjecting isolates of different sources to tissue culture (Normal human fibroblast cells-NHF) and PCR assays, while utilizing a various biochemical tests. The pks+ isolates were assessed for their cytotoxicity using the (AO/PI) double staining procedure and visualized under a fluorescence microscope. The outcomes indicated that of the 63 isolates examined, only 33 were determined to be ClbA+ E.coli, whilst 42 out of 63 were identified as UidA+ E.coli by the use of traditional PCR. The NHF cells that were infected with pks+ E.coli sustained DNA damage due to the presence of colibactin produced by pks+ E.coli and resulted killing of 83.3% NHF cells.