Uropathogenic Escherichia coli (UPEC) is the most frequent cause of urinary tract infection (UTI). Virulence factors (VFs) of UPEC in children are not well known. Circulating antibiotic resistance mechanisms in the community are increasing. In this study, the aetiological agents of UTI and antibiotic resistance mechanisms of 124 strains isolated from urine cultures from children with community-acquired UTI were determined. Virulotyping of isolated E. coli strains was also described. β-Lactam, fluoroquinolone and sulfonamide resistance genes as well as integrons were detected by PCR. E. coli phylogenetic groups and 25 VFs were sought by multiplex PCR. E. coli was the most frequent aetiological agent (88.7%), of which 48.2% belonged to phylogenetic group D and 35.5% to group B2. Moreover, 81.8% were considered UPEC and >93% had virulence structures, with kpsMTII, fimH and iutA being the most frequent. Most of the E. coli isolates were susceptible to amoxicillin/clavulanic acid (AMC) (87.3%), nitrofurantoin (97.3%), cefuroxime and third-generation cephalosporins (100%). Resistance levels to oxyimino-cephalosporins were higher in non-E. coli isolates, with circulation of integrons, blaCTX-M-2 and blaCMY-2 detected in the community. Moreover, 8.1% of isolates were resistant to fluoroquinolones, with qnrB found in two isolates. Resistance to trimethoprim/sulfamethoxazole was found in 37.9% of isolates, with 85.5% harbouring sul genes. E. coli isolated from children with UTI presented high rates of VFs. Nitrofurantoin, AMC and cefuroxime would be suitable antibiotics to treat UTI in children. However, the presence of integrons (fundamentally class 1) and circulation of broad-spectrum β-lactamases in the community makes continuous surveillance necessary.
Keywords: Antibiotic resistance; UPEC; UTI; Virulence genes.
Copyright © 2014 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.