Prevalence of Toxigenic Genes in Escherichia Coli Isolates From Hospitalized Patients in Zabol, Iran

Abstract

Background: Uropathogenic Escherichia coli (UPEC) are a common causative agent of urinary tract infections. Strains of UPEC encode a number of virulence factors that facilitate their dissemination and persistence within the host. To diminish the burden of UPEC, using effective preventive measures, data on virulence factor prevalence in different geographic regions must be assessed. Objectives: As no such data was available for this geographic region of Iran, the purpose of this study was to analyze the prevalence of ten UPEC virulence genes among 100 E. coli isolates collected from patients with urinary tract infections (UTI) in Zabol, Iran. Patients and Methods: One hundred UPEC obtained from patients with urinary tract infection were screened by the polymerase chain reaction (PCR) with primers specific for the following UPEC virulence genes: astA (enterotoxins), cdtB (enterotoxins), cvi/cva (colicin V operon), ibeA (an invasive protein), iss (increased serum survival protein), iutA (aerobactin), kpsII (group 2 capsule), neuS (K1 polysialyltransferase), tsh (an adhesive and proteolytic protein), and vat (vacuolating autotransporter toxin). Results: Amongst the total of 100 UPEC isolates, 99 (99%) isolates were found to carry the studied virulence genes. Twenty-six different virulence patterns were identified. The prevalence of astA, cdtB, cvi/cva, ibeA, iss, iutA, kpsII, neuS, tsh and vat were 29%, 0%, 19%, 67%, 47%, 99%, 98% 96%, 1% and 18%, respectively. Conclusions: We concluded that major differences exist in the prevalence of virulence factors between different UPEC isolated from different countries. Detecting these genes as primary controllers of UPEC virulence may aid in better management of related infections.