[Difficulties of fungus detection in corneal culture medium]. / Schwierigkeiten beim Pilznachweis in Hornhautkulturmedium.

UNLABELLED: It is not always possible to prevent the growth of microorganisms in organ culture for cornea preservation, despite many prophylactic measures. It is especially difficult to prove the presence of fungi in the cultural medium. MATERIALS AND METHODS: A culture medium was examined for sterility after 8 days' storage of cornea in organ culture. To prove the presence of fungi a culture of Sabouraud 2% glucose-agar was prepared and its growth examined by light microscopy. RESULTS: After 8 days of preservation we noticed a color change in the cultural medium and suspected contamination with fungi. Coagulase-negative Staphylococci could be cultivated from the conjunctival smear obtained before preparation of the cornea only. Routine screening of microbiological contamination did not show any results. We were able to identify an Aspergillus species only after preparing a special culture. The conjunctival smear as well as the cultural medium of the other eye of the same donor showed no contamination. CONCLUSIONS: In spite of the fact that microbiological contamination can be seen macroscopically, it is difficult to prove the presence of a specific microorganism and even more so when dealing with fungus. Especially in these cases the incubation of the cornea in media might have an advantage because contamination can be suspected by just looking at the medium. By excluding these preparations from transplantation we can possibly prevent infections, even when routine examinations show negative results.

[Antimicrobial decontamination of corneal donor material: infection prevention and quality assurance]. / Antimikrobielle Dekontamination von Hornhautspendermaterial. Infektionsprophylaxe und Qualitätssicherung.

BACKGROUND: Microbiological examinations in eye banks have found an increased contamination rate in preservation media. We studied the effect of prolonged submersion time for decontaminating donor globes. MATERIALS AND METHODS: We retrospectively analyzed the primary contamination of conjunctival smears in 76 cornea donors. The submersion time of donor eyes in PVP iodine solution before preparation was prolonged from 1 min to 5 min, and the contamination rate of storage vessels was compared. RESULTS: In 13 of the 76 conjunctival smears we found no contamination. Before prolonging submersion time, the preservation medium was contaminated in 15 cases, but after 5 min no contamination was observed. CONCLUSION: Prolonging the submersion time of donor globes from 1 to 5 min was effective. The model presented here provides guidelines for existing eye banks as well as for those yet to be established.