Abstract
The aim of this study was to analyze the molecular characteristics and survey the frequency of antibiotic and virulence gene genotypes in Escherichia coli isolated from hospitalized patients with urinary tract infection and to determine their antibiotic resistance patterns. A total of 250 E. coli strains were isolated from urine specimens obtained from suspected cases with urinary tract infections at different hospitals located in Taif city, Saudi Arabia. Antibiotic susceptibility testing for these isolates was executed using the disk diffusion method. The frequency of different virulence genes expressed in E. coli was detected by polymerase chain reaction (PCR) assay. Repetitive sequence repeat PCR (Rep-PCR) was used for genotyping all isolates. In addition, phylogenetic grouping was also performed on E. coli isolates.
Out of 250 isolates, 42 isolates (16.8%) belonged to the emerging pathogens such as necrotoxigenic Escherichia coli (NTEC). The prevalence of the genes Afa, pyelonephritis associated pili (pap genes) and S-family adhesions (sfa gene) among the isolated strains was 100% in each of the 42 tested isolates. TheStx gene was present in 11 (26.2%) isolates, Stx1 in 4 (9.5%) and Stx2 in 7 (16.7%) isolates. Interestingly, the cytotoxic narcotizing factor type 1 (cnf) gene was not found in any isolate. All isolates (100%) were sensitive to fosfomycin, imipenem and tigecycline and the majority of them were highly resistant to piperacillin (76%). Due to the increase of E. coli with multiple virulence genes, continuous investigation about the efficacy of antibiotics is necessary.