A study of normal bacterial flora of the conjunctiva in patients undergoing cataract surgery in a rural teaching hospital in R. R. district

Abstract

Introduction: Eye harbours bacteria from the time of birth throughout life. Disease will be caused, when the normal flora lose co-dependence and co-regulation with the host. Knowing the organism found most frequently in the ocular flora and their antibiotic sensitivity may provide a better guide in choosing an antibiotic for prophylaxis of postoperative endophtalmitis. Materials and methods: 100 patients from the ophthalmology department of various age and sex were studied. Swabs were cultured aerobically on sheep blood agar, chocolate agar, Mac Conkey agar and nutrient agar media. All the isolates were subjected to antibiotic sensitivity of Kirby Bauer disc diffusion method. Results: Out of 100 patients 54% were females and 46% were males. The conjuctival swab of 48% of patients was sterile. The predominant isolate was Staphylococcus epidermidis (32%) followed by diphtheroids (11%). All the isolates were sensitive to gentamicin, tobramycin, ciprofloxacin. Conclusion: Conjunctival colonization with aerobic bacteria accounts for approximately 50% of healthy people. The inner canthus was the most contaminated site. Coagulase-negative staphylococci are the main components of this flora. Instillation of antibiotics into the conjunctival sac to make it sterile prior to surgery can prevent post-operative infection by the normal bacterial flora of conjunctiva.