Phenotypic Characterisation of Uropathogenic Escherichia coli: Virulence Factors, ESBL Production, and Antibiogram in a Tertiary Care Hospital in Bihar

Background Uropathogenic Escherichia coli (UPEC) is responsible for 50-90% of all urinary tract infections (UTIs) worldwide, with increasing antimicrobial resistance posing a significant public health threat. This study aimed to characterise UPEC isolates from a tertiary care hospital in Bihar by detecting virulence factors and determining their antibiogram. Methods A total of 246 UPEC isolates were collected from outpatient department (OPD) and inpatient department (IPD) patients at IGIMS, Patna, over 12 months. Identification was confirmed by Matrix-Assisted Laser Desorption/Ionisation Time-of-Flight Mass Spectrometry (MALDI-TOF MS) (Bruker Daltonics, Bremen, Germany). Virulence factors, including haemolysin, haemagglutination, and cell surface hydrophobicity, were assessed. Extended-spectrum beta-lactamase (ESBL) production was confirmed by a phenotypic combination of disk diffusion test. Results Of 246 isolates, females predominated (52.0%). Haemolysin was detected in 44 (17.9%) isolates, haemagglutination in 30 (12.2%), cell surface hydrophobicity in 13 (5.3%), and ESBL production in 15 (6.1%). Most isolates showed lactose fermenting (LF) colonies on CLED (80.1%). High resistance rates to ampicillin and co-trimoxazole were noted. Nitrofurantoin and gentamicin retained better activity. Conclusion UPEC isolates from IGIMS, Patna, showed considerable virulence factor prevalence and antimicrobial resistance. Nitrofurantoin and aminoglycosides remain useful therapeutic options. Routine characterisation of UPEC is essential for effective UTI management in this region.