Molecular Analysis of Virulence Determinants in Enterococcus faecalis Isolates from Urinary Tract Infections in Calabar

Enterococcus faecalis has emerged as an important nosocomial pathogen causing urinary tract infections (UTIs), particularly in catheterized and immunocompromised patients in Nigerian tertiary hospitals. Understanding the virulence gene repertoire of clinical isolates informs risk stratification and guides antimicrobial management. This study analyzed virulence determinants in E. faecalis isolates from UTI patients at University of Calabar Teaching Hospital (UCTH), Cross River State, South-South Nigeria. Midstream urine samples were collected from 90 patients with clinically suspected UTI. E. faecalis was isolated on Bile Esculin Azide agar and identified by standard biochemical tests and PCR targeting the species-specific ddl gene. Virulence genes including esp, hyl, cylA, asa1, and gelE were detected by multiplex PCR. Antibiotic susceptibility was tested against 12 antimicrobial agents including linezolid and vancomycin. E. faecalis accounted for 28% of all UTI isolates. Virulence gene carriage was high, with gelE (78%), asa1 (65%), and esp (49%) most prevalent. One isolate demonstrated vancomycin-intermediate resistance, raising concerns about emerging VRE in South-South Nigeria. The combined presence of biofilm-associated genes (esp, gelE) and surface adhesins in clinical isolates indicates significant pathogenic potential. Keywords: Enterococcus faecalis, virulence genes, UTI, gelE, Calabar.