PURPOSE: To identify and qualify bacterial organisms in conjunctival tissue of donor corneas. To correlate the frequency of positive cultures with donor age, cause of death, and time from death to collection of conjunctival samples. To investigate bacterial susceptibility to specific antibiotics. METHODS: Conjunctival samples obtained from the inferior conjunctival fornix of 242 eyes of cornea donors were collected between January and March, 1994. The samples were transferred to Stuart´s medium and then inoculated into blood, acid blood, chocolate, McConkey agars, and thioglycolate broth. Donor age, time and cause of death were recorded. Bacterial susceptibility to antibiotics was tested using the diffusion method on agar modified by Kirby and Bauer. Statistical analysis was done using the chi-square, Fisher's exact and Mann-Whitney tests. RESULTS: Microorganisms were identified in 91.7% of the samples. The most frequently isolated microorganism was coagulase-negative Staphylococcus (27.3%). Time from death to collection of the conjunctival sample was on the average 4.2 hours. The most frequent cause of death was cardiovascular disease (26.4%). The median donor age was 62 years. No significant correlation between positive cultures and the investigated variables was found. Vancomycin inhibited bacterial growth in 100% of Gram-positive microorganisms. The sensitivity of Gram-negative bacteria to gentamicin ranged from 36.7 to 92.3%. CONCLUSION: The frequency of positive conjunctival cultures of donor corneas was 91.7%. No significant statistical difference was found between positive cultures and the investigated parameters. Vancomycin inhibited the growth of Gram-positive bacteria in 100% of the cases and the sensitivity of Gram-negative bacteria to gentamicin varied.
Cornea transplantation; Cornea; Bacteria; Tissue donors; Conjunctiva; Eye infections; bacterial
