Distribution and Evaluation of Multiple Antibiotic Resistance (MAR) Index of Clinical Isolates of Enterococcus species in Lagos, Nigeria

Enterococci are becoming one of the most important public pathogens in clinical infections with increasing resistance to antimicrobial agents. Limited data exist on the pathogens in clinical settings in the study area. Hence, we aimed to determine the occurrence of different species of Enterococcus isolated from clinical specimens at three hospitals, evaluate the resistance profile and determine their multiple antibiotic resistance (MAR) indices. A total of 66 isolates were collected from different clinical specimens, subcul¬tured, and identified according to standard cultural and biochemical characteristics. The antimicrobial re¬sistance pattern was evaluated for all identified Enterococcus spp. by the disk diffusion method using eight antibiotics. Forty-eight (48) Enterococcus isolates were identified, with Enterococcus faecalis (29, 60.4%) and E. faecium (12, 25%) being the most common. The isolates showed elevated resistance to cefpodoxime (CPD) (100.0%), gentamicin (GEN) (85.4%), tetracycline (TE) (83.3%), and erythromycin (E) (68.8%). Over a third of the isolates were resistant to ciprofloxacin (CIP) (33.3%) and vancomycin (VAN) (37.5%). There were 20 different resistance phenotypes observed, and the most common resistant pattern was CPD, TE, E, CIP, and GEN. MAR indices of the isolates were >0.2, which was observed in 97.9% of the isolates. This study indicated a significant proportion of antibiotic-resistant enterococci in the hospitals studied, suggesting a potential public health risk that should prompt more outstanding research into better infection management.