Molecular epidemiology of Escherichia coli O25b-ST131 isolates causing community-acquired UTIs in Mexico.

Escherichia coli is a common uropathogen causing community-acquired urinary tract infections (UTIs). Out of 4735 E. coli community-acquired UTIs, 10.2% were extended spectrum β-lactamases (ESBL)-producing. The identified ESBL types were CTX-M-15 (96.4%), SHV-2a (3%), and TLA-1 (1%). Of the isolates, 94.6% tested positive for plasmid-mediated quinolone resistance (PMQR) genes (aac(6')-lb-cr [92.1%] and qepA1 [7%] and for qnr-determinants [3.5%]). E. coli O25b-ST131 was identified in 25% of the isolates that harbor a non-conjugative 160-kb plasmid (IncFIA) containing the CTX-M-15, and all of these isolates were found to contain PMQR genes. This work can be useful in modeling the potential impact that may have on community-acquired UTIs in Mexico.