Bacterial flora in precataract surgery patients in a Northern Nigerian hospital

Abstract

Background: Cataract surgery is the most commonly performed surgery in most ophthalmic units. Endophthalmitis is still a dreaded complication and knowledge of the normal bacterial flora on the ocular surface and adnexae is paramount in the management of these cases. Aims and Objectives: To investigate the most frequently found ocular bacteria flora in patients scheduled for routine cataract surgery at the Ahmadu Bello University Teaching Hospital Shika Zaria, Northern Nigeria and to determine their antimicrobial susceptibility pattern. Materials and Methods: This was a cross-sectional descriptive study carried out between December 2010 and February 2012 in subjects scheduled to undergo routine cataract surgery. The lower conjunctival fornix was swabbed with a sterile swab. The samples were inoculated onto enriched and selective culture media. Antimicrobial susceptibility testing was done using the modified Kirby Bauer standardized disc-diffusion method. Data were entered and analyzed using SPSS version 20.0. Results: One hundred and fifty-seven eyes of 157 patients were sampled. The patients were between the ages of 16–96 years with a mean age of 58.8 ± 14.5 years. Positive bacterial culture was found in 35% (n = 55) of the patients. The predominant bacteria cultured was Staphylococcus epidermidis 49.1%. There was resistance to tetracycline (32.7%) and gentamycin (1.8%). All the isolates were sensitive to tobramycin and ciprofloxacin. A statistically significant relationship was found between age and culture status (P = 0.008). Conclusion: Coagulase negative Staphylococcus (S. epidermidis) was the most common commensal found in the conjunctival sacs of patients undergoing cataract surgery, and most of the isolates were susceptible to commonly used antibiotics.