Molecular Epidemiology of Multidrug-Resistant Uropathogenic <i>Escherichia coli</i> O25b Strains Associated with Complicated Urinary Tract Infection in Children.

Abstract

<h4>Background</h4>Uropathogenic <i>Escherichia coli</i> (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases.<h4>Aim</h4>The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity.<h4>Methods</h4>Resistance profiles were identified using the Kirby-Bauer method, including the phenotypic production of extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST).<h4>Results</h4>UPEC strains (<i>n</i> = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the <i>fimH</i> (95.23%), <i>csgA</i> (91.26%), <i>papG</i>II (80.95%), <i>chuA</i> (95.23%), <i>iutD</i> (88.09%), <i>satA</i> (84.92%), and <i>intl1</i> (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D.<h4>Conclusion</h4>UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics.