Resistance among urinary tract pathogens collected in Europe during 2018.

Objectives: Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis are urinary tract infection (UTI) pathogens and extended spectrum β-lactamase (ESBL)-producing pathogens exhibit co-resistance to oral fluoroquinolones (FQ) and trimethoprim-sulphamethoxazole (TMP-SMX). This study assessed the prevalence of ESBL phenotypes and co-resistance to FQ and TMP-SMX.

Methods: In total, 766 E. coli, 260 K. pneumoniae and 104 P. mirabilis from UTIs in 18 countries were evaluated for susceptibility in the SENTRY surveillance programme, and results interpreted using EUCAST criteria.

Results: E. coli, K. pneumoniae and P. mirabilis accounted for 57.1%, 11.3% and 7.8%, respectively, of the isolates. Among E. coli, resistance to levofloxacin and TMP-SMX ranged from 21.8% to 32.7% for all isolates increasing to 66.5-67.0% among those with a ESBL phenotype (17.9% of all UTI E. coli from Europe were ESBL phenotypes). In contrast, all E. coli were susceptible to meropenem. For K. pneumoniae, resistance rates for levofloxacin and TMP-SMX were 32.2-40.0% increasing to 69.1-78.6% for ESBL phenotypes. Meropenem was the most active agent, with 7.7% resistance. Among P. mirabilis resistance to levofloxacin and TMP-SMX was 26-38.5% and increased to 100% for ESBL phenotypes. No meropenem-resistant P. mirabilis were reported.

Conclusions: High co-resistance rates were observed for oral antibiotics among ESBL phenotypes raising concerns regarding empiric use of FQ and TMP-SMX for treating resistant UTIs outside of the hospital. In contrast, intravenous carbapenems retain activity against resistant UTI pathogens. New oral options with the spectrum of the carbapenems would address an unmet need for managing resistant UTIs.