Antibiotic resistance patterns of ocular surface bacterial flora

Post operative intraocular infection (endophthalmitis) is a rare but devastating complication. The present study aimed to determine the antibiotic susceptibility pattern of ocular surface bacterial flora isolated preoperatively from patients undergoing intraocular surgery. In a prospective study, 269 patients scheduled for anterior segment surgeries, were enrolled, for whom lid and conjunctival cultures were obtained on the day of surgery before application of povidone – iodine or antibiotic drops. Bacterial isolates were identified and tested for antibiotics susceptibility using Kirby-Bauer disc-diffusion technique. Of 269 studied eyes, 127(47.2%) were male. In 101 (37.5%) cases bacterial growth was positive. Isolated bacteria in order of frequency were coagulase negative staphylococci (CNS) (90.0%), coagulase positive staphylococci (CPS) (4%), diphteroid (3%), gram negative bacillus (2%) and streptococci (1%). Totally, 95% of coagulase negative staphylococci were susceptible to vancomycin, amikacin and gentamicin. Less than 70% of isolated CNS were sensitive to ceftriaxon, tetracyelin, erythromycin, oxacillin, cotrimaxazole, and penicillin. Preoperative ocular surface isolates of CNS seems to be most sensitive to vancomycin, amikacin and gentamicin. Thus, preoperative application of these medications into ocular surface is suggested.