Prevalence and association of pks+ Escherichia coli with colorectal cancer in Iraqi patients

Abstract

Colorectal cancer (CRC) is a malignant tumor in the digestive system whose incidence and mortality are high-ranking among tumors worldwide. The present work aimed to investigate the role of colibactin-produced isolates of pks+ Escherichia coli in CRC disease. Among 159 specimens, which were subjected to different examinations, a total of 57.36% (n=88) of E. coli isolates were obtained, including 32.08% (n=51) of isolates from patients with CRC, including 21.4% (n=34) from fecal specimens and 10.7% (n=17) from tissue specimens as well as 23.3% (n=37) of isolates were obtained from healthy controls, including 16.4% (n=26) from fecal specimens and 6.92% (n=11) from tissue specimens. Genomic DNA was extracted from 57 selected E. coli isolates, which obtained 20 specimens (10 from CRC patients and 10 from controls) and 37 fecal specimens (21 from CRC patients and 16 from controls) for molecular detections of two genes ( uidA and pks ). All isolates of E. coli harbored uidA gene, while 11 (55.0%) of isolates were given positive for pks , including 8 (80.0%) from CRC patients and 3 (30.0%) from healthy controls. Immunofluorescence assay (IFA) was utilized to study the effect of pks + and pks - E. coli isolates on Normal human derived adipose tissue (NHF) cell line for determining the quantification of H2AX expression. The results indicated that there was significant variation in H2AX expression between pks + E. coli isolate-treated NHF and other groups. However, there was a non-significantly variation in H2AX expression between pks - E. coli isolate treated NHF and untreated NHF (as control) tissues. The results indicated that high effect of pks + E. coli on H2AX expression in NHF cell line.