Characteristics of ESBL-positive Escherichia coli causing community-acquired UTIs in India

This is the authors' abstract. We don't add key points for this paper.

Uropathogenic E. coli (UPEC) is the predominant uropathogen in community-acquired urinary tract infections (CA-UTIs) globally. However, data from India on relationship between antimicrobial resistance, virulence factors, and clonal markers in UPEC remain scarce. We studied 80 ESBL-positive UPEC isolates causing CA-UTI across four Indian regions. Antimicrobial susceptibility done using VITEK-2. PCR assays detected ESBL genes ( bla CTX-M-15 , bla TEM ), carbapenemase genes ( bla NDM , bla OXA-48-like ), virulence genes ( fimH, pap, sfa, hlyA, aer ) and serogroup O25b. Phenotypic virulence assays assessed hemolysin, haemagglutination, biofilm and gelatinase production. All isolates susceptible to fosfomycin, with high susceptibility to nitrofurantoin (87.5%) and ertapenem (85%). Predominant resistance gene was bla CTX-M-15 (97.5%), followed by bla TEM (55%), bla NDM (16.3%) and bla OXA-48-like (5%). Biofilm formation (41.3%) most prevalent virulence trait, followed by haemagglutination (35%). Frequently detected virulence genes were pap (61.3%), fimH (55%), and aer (48.8%). The O25b serogroup found in 41.3% of isolates had lower ertapenem resistance than non-O25b strains. This study shows ESBL-producing UPEC isolates from community settings in India frequently harbour multiple beta-lactamase resistance genes and virulence factors, underscoring their adaptability and clinical threat in CA-UTIs. These findings emphasize the critical need for continued molecular surveillance, strengthened infection control, and robust antibiotic stewardship programs to mitigate the spread of multidrug-resistant, virulent UPEC strains.