Determination of phylogenetic background, fimbrial genes, and antibiotic susceptibility of Escherichia coli isolates from urinary tract infections in Bam region, Iran

Abstract

Phylogenetic analysis have shown that Escherichia coli (E. coli) strains segregate in four main phylogenetic groups A, B1, B2, and D. E. coli fimbriae increase invasive capability of bacteria to renal tissues. The purpose of this study was to determine the distribution of phylogenetic groups/subgroups among fimbrial genes and antibiotic resistance patterns of E. coli isolates from urinary tract infections (UTI), in Bam (southeast of Iran). A total of 122 E. coli isolates from patients with UTI, which were confirmed by biochemical tests, were collected. Antibiotic susceptibility of isolates was examined against six antibiotic agents by disk diffusion method. DNA was extracted and examined for detection of phylogenetic group/subgroups and also for determination of afaI BC, sfa/focDE, and papEF genes using PCR technique. E. coli isolates were distributed in phylogroups A (45.08 %), D (43.45 %), B2 (7.83 %), and B1 (4.09 %). The examined isolates belonged to six phylogenetic subgroups A0 (28.69 %), D2 (24.59 %), D1 (18.85 %), A1 (16.39 %), B2–3 (7.39 %), and B1 (4.09 %). Fimbrial genes were found in 27.85 % of isolates. Phylogroups A and D were more prevalent in antibiotic resistance patterns than other phylogenetic groups. The findings of the current study showed that A and D phylogenetic groups were dominant among our isolates. These results differ with that of other researches in other parts of the world. Further studies are required to clarify the phylogenetic background in Bam area. Antibiotic resistant seems to be a common feature of most E. coli isolates in this area.