Enterococcus-associated urinary tract infections, their prevalence and antibiotic resistance

Background: Methodology: A retrospective study was conducted using the Medical Microbiology Laboratory records of the Lagos State University Teaching Hospital. The study reviewed the in vitro antibiotic susceptibility patterns of urinary bacterial isolates from April 2020 to March 2021, focusing on Enterococcus spp. Bacteria were isolated and identified from routine urine samples using standard bacteriological methods and the Analytical Profile Index (API). Antibiotic susceptibility tests (AST) were performed using the modified Kirby-Bauer disk diffusion method, with susceptibility breakpoints determined by the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: A total of 82 patients (5 outpatients and 77 inpatients) with Enterococcus-associated UTIs were identified. The species distribution was 70.7% E. faecalis and 29.3% E. faecium. E. faecium exhibited greater resistance to levofloxacin and tetracycline but greater sensitivity to amoxicillin compared to E. faecalis. Both species showed high sensitivity to tigecycline, meropenem, and fosfomycin. Conclusion: The prevalence of Enterococcus-associated UTIs in this study was 3.6% (82/2253), with hospital-acquired Enterococcus spp. accounting for 3.4% (77/2253). E. faecium isolates were significantly more resistant to levofloxacin and tetracycline than E. faecalis. The high rate of multidrug resistance (MDR) in both species underscores the importance of promoting rational antibiotic use to prevent the emergence of resistant organisms.