Journal of Bacteriology & Parasitology

Abstract

Drug Resistance and Molecular Characteristics of Escherichia coli Isolates Associated with Acute Pyelonephritis

Xao-Li Cao, Xue-Jing Xu, Han Shen, Zhi-Feng Zhang, Ming-Zhe Ning and Jun-Hao Chen

Acute pyelonephritis (APN) as one of the most severe form of UTIs may result in significant morbidity. We aim to investigate the antimicrobial susceptibilities and genetic traits of Escherichia coli isolates associated with APN.

Totally, 64 APN E. coli isolates were analyzed for the antimicrobial susceptibilities, phylogenetic groups, resistance and virulence determinants, plasmid replicons, pulsed-field gel electrophoresis (PFGE), and Multi-locus sequence types (MLST).

High percentages of resistance (>65.0%) to ampicillin/sulbactam and levofloxacin were observed, imipenem and fosfomycin displayed good in vitro sensitivity (>93.0%). Most of the strains belonged to phylogenetic group D (50.6%) and B2 (21.6%), D strains were more resistant than B2 ones towards the cephalosporins tested (p0.05). Thirty-six (56.3%) blaCTX-M, 3 (4.7%) rmtB, and 13 plasmid mediated quinolone resistance (PMQR) genes were identified. Plasmid replicon IncF (54/64, 84.4%) and virulence factors (VFs) fimH (57/64, 89.1%) was the most prevalent. PFGE and MLST displayed genetic diversity. Prevalence of ompT, fdeC, PAI, and usp were higher among B2 strains than that in D ones (P<0.05). Statistical associations between antimicrobial resistances and VFs were found.

This study provides new data on the molecular epidemiology and pathogenesis of E. coli isolates associated with APN.