Extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae from urinary tract infections: Evolution of antimicrobial resistance and treatment options

Background and objectives: A study of the susceptibility to antimicrobials of the extended spectrum beta-lactamase phenotypes (ESBL) in Escherichia coli and Klebsiella spp. was performed to discover the evolution of this type of resistance from urinary tract infections. Material and method: A retrospective study was carried out between 2012 and 2016. Susceptibility to ciprofloxacin, tobramycin, cefoxitin, fosfomycin, nitrofurantoin, co-trimoxazole, and carbapenems was analyzed using MicroScan system. Results: A total of 95,399 samples were processed and 9,772 E. coli, 1,784 Klebsiella pneumoniae and 248 Klebsiella oxytoca were isolated. ESBL strains were more frequent in women, although they decreased during 2015 and 2016 (65.7-67.2%). The prevalence of K. pneumoniae ESBL increased annually (28.1% in 2016). The average prevalence of E. coli ESBL was 10.5% with few oscillations. Higher resistance occurred to ciprofloxacin and cotrimoxazole, 89.5 and 94.7% in 2015, respectively, and there was lesser resistance to imipenem. Fosfomycin and nitrofurantoin were very active on E. coil ESBL. Conclusions: ESBL producing E. coli and K pneumoniae were prevalent, especially the latter, with a significant resistance to ciprofloxacin and cotrimoxazole. Susceptibility to imipenem was high. (C) 2017 Elsevier Espana, S.L.U. All rights reserved.