Abstract
Purpose:
Current screening practices for donor corneal tissue include donor nasal and sputum cultures. Samples with positive cultures for some pathogens are often excluded automatically. Others require medical consultation. The purpose of this study is to determine whether corneas taken from individuals with positive sputum cultures exhibit the same microorganisms found in those sputum cultures.
Methods:
Corneas from donors with positive sputum cultures prior to death were selected for study. The initial cohort was comprised of 13 tissue samples. In situ collections of corneoscleral rims were obtained using sterile technique, placed in Optisol-GS media, transported to the eye bank on ice, and maintained at 40C for a total of five (5) days from death in order to replicate the average time from death to transplantation. After five days, the corneas were removed from the media aseptically and two rim swab cultures (one for bacteria, one for fungus) were obtained. The cultures were developed in a commercial laboratory for five (5) days for bacterial cultures, and seven (7) days for fungal culture, before being scored on a 0-4+ scale.
Results:
In the initial cohort, corresponding sputum isolates included a variety of microorganisms including Klebsiella sp., Pseudomonas spp., Enterobacter spp., Escherichia coli, Staphylococcus aureus as well as Candida spp. All rim cultures- of bacteria and of fungus- were scored as 0 (no growth). Extending the incubation time of fungal cultures for up to three weeks still resulted in a 0 (no growth) score for all samples.
Conclusions:
Current evaluation of potential corneal donor tissue includes disqualification for some positive sputum culture results. Our data suggest that for the pathogens under study, positive sputum cultures prior to death are not correlated with positive graft cultures after preparation. We conclude that disqualification criteria for eye banks may be adjusted to reflect these findings, with the potential gain of scarce and valuable tissues that are still suitable for transplantation.
Keywords: 741 transplantation •
483 cornea: storage •
479 cornea: clinical science