Coexistence of PMQR and ESBL genes among clinical Escherichia coli isolates from community-acquired UTI in Mexicali, on the US-Mexico border

Escherichia coli is an opportunistic pathogen and a leading cause of Community-Acquired Urinary Tract Infections (CA-UTIs). E. coli can harbor multiple genetic resistant determinants, such as Extended Spectrum Beta-lactamases (ESBL) and Plasmid-Mediated Quinolone Resistance (PMQR) genes, complicating the empirical treatment of UTIs with β-lactams and quinolones. The aim of his study was to characterize ESBL and PMQR genes among E. coli isolates from CA-UTI in Mexicali, Mexico Isolates were collected from January to December 2023. Identification was performed by MALDI-TOF, and ESBL-producing determination and antimicrobial susceptibility by Vitek 2. Detection of ESBL and PMQR, and phylotyping were performed by PCR. Genetic diversity was determined by Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR). Eighty-nine E. coli isolates were collected from CA-UTIs. All exhibited resistance to ciprofloxacin, ceftriaxone, and cefotaxime, while being susceptible to carbapenems and ceftazidime/avibactam. All isolates tested positive for an ESBL gene, with bla_CTX-_M (98.9 %) being the most prevalent. Five isolates tested negative for PMQR genes; the remaining showed aac(6')-lb-cr present in 85.3 %. Coexistence between ESBL and PMQR genes was noted in 95.5 %. Most prevalent plylogenetic group was group B2 (74.2 %). This study provides valuable regional data, highlighting a public health problem due to the high prevalence of ESBL and PMQR genes in E. coli responsible for CA-UTI, which are linked to multidrug resistance. Genetic diversity was found, suggesting multiple sources of resistant strains in the community. These findings underline the need for surveillance and control to limit the spread of resistant E. coli, locally and globally. DATA SUMMARY: The authors confirm all supporting data, code, and protocols have been provided within the article or through supplementary data files.