Multidrug resistance and risk factors associated to community-acquired urinary tract infections caused by Escherichia coli in Venezuela

Abstract

Introduction: The treatment urinary tract infections (UTIs) has become more challenging because of the increasing frequency of multidrug-resistant (MDR) Escherichia coli which can be found in the community. Objective: Characterize MDR E. coli isolates causing community-acquired UTIs in Cumana, Venezuela, and associate possible risk factors for infection by ESBL-producing isolates. Materials and methods: All patients attending the urology outpatient consultation and emergency unit in a Cumana Hospital, Sucre state, Venezuela, showing UTIs from January through June, 2014, were included. Detection of blaTEM, blaSHV and blaCTX-M genes was carried out by PCR. Results: A high prevalence of MDR E. coli (25.2%) was found, with 20.4% of the isolates producing ESBLs. Those isolates producing ESBL showed high frequency (66.7%) of simultaneous resistance to trimethoprim-sulphamethoxazole, fluoroquinolones and aminoglycosides compared to non-producing isolates (2.4%). Of the resistant isolates, 65.4% showed blaTEM gene, 34.6% blaCTX-M and 23.1% blaSHV. The blaCTX-M genes detected belonged to the CTX-M-1 and CTX-M-2 groups. Plasmid transfer was demonstrated by in vitro conjugation in 17 of the 26 ESBL-producing isolates. All three genes detected were transferred to the transconjugants. Age over 60 years, complicated UTI and previous use of catheter predisposed for infection by ESBL-producing E. coli. Conclusions: The high frequency of MDR/ESBL-producing isolates should alert the regional health authorities to take measures to reduce the risk of outbreaks caused by these types of bacteria in the community.