Prevalence and risk factors for extended-spectrum β-lactamase-producing Escherichia coli causing community-onset urinary tract infections in Colombia

Introduction Urinary tract infections (UTI) are common in the community. However, information of resistant isolates in this context is limited in Latin America. This study aims to determine the prevalence and risk factors associated with community-onset UTI (CO-UTI) caused by extended-spectrum β-lactamase (ESBL)-Producing Escherichia coli in Colombia. Materials and methods A case-control study was conducted between August and December of 2011 in three Colombian tertiary-care institutions. All patients who were admitted to the Emergency Department with a probable diagnosis of CO-UTI were invited to participate. All participating patients were asked for a urine sample. ESBL confirmatory test, antibiotic susceptibility, and molecular epidemiology were performed in these E. coli isolates (Real Time-PCR for bla genes, repetitive element palindromic PCR [rep-PCR], multilocus sequence typing [MLST] and virulence factors by PCR). Clinical and epidemiological information was recorded, and a statistical analysis was performed. Results Of the 2124 recruited patients, 629 had a positive urine culture, 431 of which grew E. coli; 54 were positive for ESBL, of which 29 were CTX-M-15. The majority of ESBL isolates were susceptible to ertapenem, phosphomycin and amikacin. Complicated UTI was strongly associated with ESBL-producing E. coli infections (OR = 3.89; 95% CI: 1.10-13.89; P = .03). CTX-M-15-producing E. coli showed 10 different pulsotypes, 65% were PT1 or PT4, and corresponded to ST131. Most of these isolates had 8 out of the 9 analysed virulence factors. Discussion E. coli harbouring bla_CTX-M-15 associated with ST131 is still frequent in Colombia. The presence of complicated CO-UTI increases the risk of ESBL-producing E. coli, and must be taken into account in order to provide an adequate empirical therapy.