The Frequency of Some Colibactin Genes Amongst the Clinical Strains of E. coli Isolated From Urinary Tract Infections in Iraq

Abstract

Escherichia coli has been recognized worldwide as the most common causative agent for severe infections of the urinary tract. Colibactin is a genotoxin produced through a gene cluster called polyketide synthase (pks) island by members of Enterobacteriaceae. Limited information is available about the frequency of colibactin in E. coli isolates in Iraq. Hence, this study aimed to examine the frequency of some colibactin genes (CIbA and CIbQ) in clinical isolates of E. coli obtained from urinary tract infections (UTIs) in Iraq. Between October 2023 and January 2024, 120 urine samples were collected from females diagnosed with UTIs in Iraqi hospitals. 70 E. coli isolates were isolated after identification by biochemical methods and confirmed by molecular technique. In particular, the 16S rRNA gene was targeted using specific primers to confirm their identity. Conventional polymerase chain reaction (PCR) was employed to detect the CIbA and CIbQ genes and confirm the presence of colibactin. The findings of this study revealed a high prevalence of colibactin-producing isolates (40%, 28/70) compared to colibactin-non-producing isolates (60%, 42/70) with non-significant differences (p>0.05). In conclusion, the frequency of colibactin genes is high in E. coli strains isolated from UTIs in Iraq. The presence of pks-positive isolates at a high frequency is concerning, as it suggests the spread of a highly genotoxic strain in urinary tract infections in Iraq that could potentially lead to the development of urinary tract cancer diseases.