High Rates of Antimicrobial Resistance and Emergence of High-Risk Clones in Community-Acquired Uropathogenic Escherichia coli.
Vívian Santos Galvão, Adriano Souza Santos Monteiro, João Lucas Pinheiro Leite, Isabela Oliveira Sousa, Soraia Machado Cordeiro, Joice Neves Reis
Abstract
Open AccessUrinary tract infection (UTI) is the most common bacterial infection globally and is often treated empirically in community settings, contributing to antimicrobial resistance. Uropathogenic E. coli (UPEC) is the leading cause of community-acquired UTIs (CA-UTIs), yet data on its clinical and molecular characteristics remain limited. To investigate the clinical and microbiological features of CA-UTIs, focusing on antimicrobial resistance, phylogenetic groups, virulence genes, and clonal profiles. Randomly selected E. coli isolates from CA-UTI cases underwent antimicrobial susceptibility testing. PCR was used to detect β-lactamase genes, phylogenetic groups, and key virulence factors. MLST was used for clonal typing. Clinical and demographic data were obtained through structured interviews. Among 98 CA-UPEC isolates, most were from female patients (95.9%), median age 48 years. High resistance was observed to ampicillin (50.0%), trimethoprim-sulfamethoxazole (34.7%), and fluoroquinolones (33.7%), while resistance to nitrofurantoin and fosfomycin was low (1%). Multidrug resistant (MDR) strains accounted for 24.5%, with 6.1% being ESBL producers, all harboring blaCTX-M-type genes. Phylogenetic group B2 (48.0%) carried the most virulence genes, while group A had more MDR strains. Common virulence genes included fimH (95.9%), PAI IV536 (77.6%), and fyuA (76.5%). Genes aer, and iutA were linked to MDR, while papC, sfa, hlyA were more common in non-MDR isolates. ST1193, a high-risk clone, was the most prevalent (25.0%), found only among MDR strains. ST73 and ST127 were associated with multiple virulence genes but were non-MDR. Nitrofurantoin and fosfomycin remain effective options for CA-UTIs. Continuous surveillance is vital to guide treatment and track resistance trends.