Prevalence and antimicrobial susceptibility patterns of bacteria colonizing the external ocular surfaces of patients undergoing ocular surgeries at Bugando Medical Center in Mwanza, Tanzania

Abstract

The study participants had a median age of 62.5 (interquartile range: 39.5-75.0) years. A total of 78.1% (175/224) ocular swabs were culture positive yielding 196 bacterial isolates. Staphylococcus epidermidis [43.4% (n = 85)], Staphylococcus aureus [21.9% (n = 43)] and Pseudomonas aeruginosa [14.3% (n = 28)] were the most common bacteria. There were low proportions of resistance among predominant Gram-positive and Gram-negative bacteria to gentamicin (≤ 25.0%), and similarly, low resistance among Gram negative bacteria was observed against 3rd generation cephalosporins (≤ 25.0%) and piperacillin-tazobactam (0.0%). Variable resistance profiles were notable to the most commonly used antibiotics (ciprofloxacin and tetracycline: 0.0-66.7%). Our findings underscore an urgent need to revisit antibiotic prophylactic guidelines for ocular surgeries in this tertiary hospital, and calls for prospective evaluation of incident SSIs post-ocular surgeries to guide specific management.