High prevalence of phylogroup B2 in Extended-Spectrum-β-Lactamase- producing Escherichia coli isolates in patients with urinary tract infections in Tehran

Introduction and Objectivess: Uropathogenic Escherichia coli (UPEC) are the major causing of urinary tract infections (UTIs). Incidence of UTI due to Multi-drug Resistant and Extended- Spectrum Beta-Lactamases (ESBLs) producing Escherichia coli (E.coli) are increasing worldwide. Most E. coli strains are classified under four main phylogeny groups B2, B1, A, and D. The present study was carried out to determination common phylogroups in ESBLs producing E.coli in children with UTIs. Materials and Methods: Current study was carried out between April 2017 to January 2018 in 100 isolated E.coli from urine of children with symptomatic UTI in Tehran; Iran. Screening for ESBL-producing E. coli isolates was done by standard methods according to CLSI 2017 guidelines. Phylogenetic grouping of all positive ESBL isolates were done by using of the triplex PCR method using by based on combination of three genetic markers chuA, yjaA and TspE4.C2. Results: The ESBLs were detected in 100 of 220 E.coli isolates. Among these, the predominant phylogenetic group was B2 (n=84; 76.3%), followed by A/C (n=15; 13.7%) and D (n=9; 10 %). There was a statistically significant difference between phylogeny groups and antibiotic resistance to ciprofloxacin (69% in group B2), trimethoprim + Sulfamethoxazole (90% in group B2) and nitrofurantoin (18.2% in group A vs. 7% in groupB2). All the isolates of E. coli group D were sensitive to nitrofurantoin and amikacin. Due to high prevalence to resistance to ciprofloxacin (62% in ESBL positive isolates), it is is suggested that ciprofloxacin as empirical therapy for UTI should be reconsidered. Conclusion: Our study showed that phylogroup B2 and D was significantly associated to highly antibiotic resistance than group A.

کلیدواژه ها:

urinary tract infection ، extended spectrum β-lactamases ، phylogenetic group