EEBA Program (PDF/3MB) - EEBA - Annual Meeting

FALSE NEGATIVE RESULTS IN TISSUE BANKING: THE CORNEAL TISSUESL. Giurgola¹, R. Mistó², F. Pateri², C. Gatto¹, J. D’Amato Tothova¹¹Research and Development Department of Alchimia S.r.l.; ²Azienda Ospedaliera San Gerardo, ItalyPurpose: The use of antibiotic cocktails during corneal processing can lead to an antibiotic carry-overeffect, which in turn can generate false negative results in microbiological analysis. To investigate theimpact of antibiotic residues on microbiological analyses of organ cultured donor corneas.Methods: Twenty-four corneal tissues were retrieved by the personnel of the Eye Bank of Monza (Italy)and transported to the bank in Eusol-C (AL.CHI.MI.A., Italy). Tissues were transferred to Tissue-C (AL.CHI.MI.A., Italy), stored for 12-14 days at 31°C and then placed in the deswelling/transport mediumCarry-C (AL.CHI.MI.A., Italy) at room temperature for 24 h. Microbiological analyses were performedpre-processing on Eusol-C and post-processing on Tissue-C and Carry-C by the Eye Bank of Monza,according to bank standard procedures using BacTEC plus aerobic/anaerobic and, in parallel, byAL.CHI.MI.A. with sterility test according to the European Pharmacopeia, after removing potentialinterfering antibiotics with the ResEP device (AL.CHI.MI.A., Italy).Results: Pre-processing microbiological analysis of the media, after removing potential interferingantibiotics with ResEP device, showed that 75% of the samples were contaminated (Staphylococcusspp.). 25% of such contaminations were not detected by BacTEC, thus yielding false negative results.45% of the samples remained positive (Bacillus spp., Candida spp. Staphylococcus spp.) at the end ofthe process. None of these contaminations was detected by BacTEC.Conclusions: Removal of antibiotic residues from corneal storage media with the ResEP deviceresulted in a significant number of false negative results in the microbiological analyses of the media.The presence of contaminants in the media at the end of the storage process indicates that standardcorneal storage media do not guarantee efficient decontamination of donor corneas.58