Changes in the characteristics of community-onset fluoroquinolone-resistant Escherichia coli isolates causing community-acquired acute pyelonephritis in South Korea

Abstract

Purpose: This study aimed to examine the changes in the characteristics of community-onset fluoroquinolone-resist ant (FQ-R) Escherichia coli isolates causing community-acquired acute pyelonephritis (APN) in South Korea. Methods: Blood or urine samples were prospectively collected from patients aged > 15 years with community-acquired APN who were admitted to one of the eight Korean hospitals included in this study between September 2017 and August 2018. Phylogenetic typing, multi -locus sequence typing, and molecular characterization of 13-lactamase resistance and plasmid-mediated quinolone resistance (PMQR) determinants were performed. The data were compared with those from a previous study with the same design conducted in 2010-2011. Results: A total of 300 and 346 isolates were identified in 2010-2011 and 2017-2018, respec-tively. Among them, 76 (22.0%) and 77 (25.7%) FQ-R isolates were identified in 2010-2011 and 2017-2018, respectively. A significantly higher antimicrobial resistance against third-to fourth -generation cephalosporins, including cefotaxime (23.9% vs. 77.9%, P < 0.001), were observed among FQ-R isolates in 2017-2018 than among those in 2010-2011. A higher proportion of ST131 isolates (27.6% vs. 66.2%, P < 0.001), as well as isolates that had extended-spectrum 13-lactamase (ESBL)/plasmid-mediated AmpC 13-lactamase (PABL) (23.7% vs. 79.2%, P < 0.001), was observed in 2017-2018 than in 2010-2011. Further, more PMQR determinants (11.8% vs. 40.8%, P < 0.001) were observed in 2017-2018 than in 2010-2011. Conclusions: Among uropathogenic FQ-R E. coli isolates in South Korea, the prevalence of ST131 and the proportion of isolates containing ESBL and/or PMQR determinants have increased. Copyright 2022, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.