A suitable and efficient procedure for the removal of decontaminating antibiotics from tissue allografts

Abstract

The presence of residual antibiotics in tissue allografts after decontamination with antibiotic cocktails may result in widely documented adverse effects in predisposed subjects. Moreover, antibiotic residues may mask contaminating microorganisms, resulting in falsely negative sterility tests, with potential risk of post-surgical infections. The objective of the present study was to define a rinsing procedure capable of eliminating antibiotic residues from cardiovascular, bone and skin tissues after decontamination with BASE.128. Different washing patterns, employing BASE medium, were applied. The presence of antibiotic residues in tissue homogenates was assessed by agar diffusion test at different stages of tissue processing. To test whether antibiotic residues can result in falsely negative microbiological analysis, we induced a superficial tissue contamination with known inoculum concentration. By employing four different porcine tissues, we here report direct evidence that the presence of even limited amounts of antibiotics in decontaminated tissues interferes with sterility testing. This has implications in terms of increased risk of infections in allograft recipients. To minimize this risk, we developed a procedure for extensive removal of antibiotics from allografts, allowing for subsequent detection of microbial contaminations that may occur during transportation, storage or processing prior to allograft transplantation. Our study emphasizes the importance of validating all processes and analytical methods in tissue banking, in order to warrant tissue safety. This will minimize the risks of post-surgical infections as well as antibiotic-induced anaphylaxis in predisposed patients.