Removal of antibiotic residues from samples undergoing standard microbiological analyses in tissue bank

Purpose: To evaluate the use of ResEP syringe prototype for removal of antibiotic residues from samples undergoing standard microbiological analyses in tissue banks.

Methods: Twenty cardiovascular tissues from HB and NHB donors were processed according to standard operating procedures by two cardiovascular tissue banks. After transport to the bank, tissues were decontaminated with BASE.128 (AL.CHI.MI.A. S.r.l.) at 4°C for 24h or at 4°C for 72h. All tissues were rinsed with BASE (AL.CHI.MI.A. S.r.l.) and cryopreserved with 10% DMSO in BASE with addition of 2% of human albumin (only one bank).
Standard bacteriological tests were performed on transport, rinsing and cryopreservation liquids (BACT-ALERT Biomerieux) and tissue (thioglycollate/TSB media). Additional bacteriological tests were performed on liquid samples using ResEP syringe prototype (AL.CHI.MI.A. S.r.l.), after antibiotic removal. The presence of antibiotic residues in all samples undergoing the microbiological analyses was evaluated by HPLC.

Results: Almost all investigated tissues were initially contaminated with one or more bacterial spp. (Staphylococcus spp., Streptococcus spp., Propionibacterium spp.). Post-decontamination microbiological tests of all investigated tissues and liquids were negative. HPLC analysis showed that after decontamination, important antibiotic residues were present in rinsing and cryopreservation liquids with highest content found after decontamination at 4° C for 72h. The ResEP syringe removed efficiently antibiotic residues from all liquid samples prior to microbiological analysis.

Conclusions: Use of ResEP syringe prototype allowed to eliminate antibiotic residues from liquid samples undergoing microbiological analysis, thus eliminating the interference with microbial growth. Tissue decontamination with BASE.128 eliminated all contaminants from human cardiovascular tissues.