Contamination of donor cornea by gentamicin-resistant organisms.

Cultures of the donor corneoscleral rims in 70 consecutive penetrating keratoplasties showed microbial contamination in 14 cases. All positive cultures were tested by standard microdilution broth method for sensitivities to gentamicin, an antibiotic routinely used in McCarey-Kaufman transport medium. Seven of 15 organisms demonstrated resistance to gentamicin at concentrations above 100 micrograms/ml. These results indicated the selection of more antibiotic-resistant microorganisms in antibiotic-supplemented medium and the need for appropriate antibiotic prophylaxis at the time of surgery.