BACTERIAL RESISTANCE AFTER SHORT-TERM EXPOSURE TO ANTIBIOTICS

Purpose: To determine if there is a difference in antibiotic sensitivity to coagulase-negative Staphylococcus (CNS) cul-tured from the host versus the donor cornea at the time of corneal transplantation. Then to apply this knowledge to pre-operative preparation of patients undergoing eye surgery. Method: A total of 923 donor corneas stored in Optisol and 895 host corneas with no preoperative antibiotic exposure were cultured. Forty-two CNS positive cultures grew from the donor corneas and 40 from the host corneas (P =.5). Results: There was an increase in resistance in the bacteria cultured from the donor compared with the host. The most striking changes occurred in host versus donor to: ciprofloxacin 27.5 % (P =.0033); gentamicin 27 % (P =.0113); tobramycin 31.6 % (P =.059). The combination of polymixin, bacitracin, and neomycin (P/B/N) was significantly better than ciprofloxacin, gentamicin, and tobramycin or the combination of ciprofloxacin, gentamicin, and tobramycin (C/G/T) (P =.0007). Conclusion: The combination of C/G/T exhibited the highest change to resistant bacteria. P/B/N was the most effective commercially available preparation. These results should be considered when making the decision about which preop-erative antibiotic to use, if any. Trans Am Ophthalmol Soc 2002;100:137-14