Evaluation of the Sterility Test for Detection of Microbial Contaminants of Allografts

Abstract

Tissue banks routinely use a sterility test to determine the suitability of processed tissue prior to release. However, many tissue banks also accompany the sterility test with additional types of media to ensure detection of slower-growing or more fastidious organisms that may not be detected in the standard two media/two incubation temperature sterility test. This study was designed to determine if a standard sterility test is capable of detecting the wide variety of organisms that may be isolated from human tissue thereby making the additional plated media unnecessary. More than 100 isolates, representing more than 90 different species were tested. All isolates exhibited growth in at least one of the two standard sterility test media within the 14-day incubation period.

Residual Antibiotics in Decontaminated Human Cardiovascular Tissues Intended for Transplantation and Risk of Falsely Negative Microbiological Analyses

“…Validated rinsing procedures to remove antibiotic residues from tissue samples might enhance bacterial recovery [23] . The dilution of antibiotics under minimal inhibitory concentration is an acceptable approach [9] – [11] ; however, it requires high volumes of growth media in case of high antibiotic concentrations.…”

“…Microbiological analysis is closely related to tissue safety as results are used to determine the suitability of the tissue for transplantation [11] . Moreover, in case of falsely negative microbiological results, the inefficacy of the decontamination procedure is not immediately apparent and can potentially lead to the release of contaminated tissue, thus compromising the safety of the allograft recipient [15] , [22] .…”

“…No specific standards for microbiological analysis in tissue banking are available. Consequently, each tissue bank shall validate the method for tissue and liquid sample microbiological analysis, which is essential to determine whether the tissue can be released for transplantation [11] – [13] . The microbiological analysis is usually performed by means of automated blood culture systems or direct inoculum of growth media [13] , [14] .…”

Method for sterility testing of corneal storage and transport media after removal of interfering antimicrobials: prospective validation study in compliance with the European Pharmacopoeia

“…Because no specific standards for sterility testing are available in tissue banking, each tissue bank validates its own method. 11–13 …”

From Penicillin-Streptomycin to Amikacin-Vancomycin: Antibiotic Decontamination of Cardiovascular Homografts in Singapore

“…An effective method shall give an accurate result by improving the microbial detection rate and eliminating the potential of inhibitory effect caused by residual antibiotics [18]. Due to this potential for inhibition of bacterial and/or fungal growth, antibiotics and sterility test must also be validated to ensure that any bacteriostatic and/or fungistatic properties of the tissues and solutions do not adversely affect the reliability of the test results caused by false-negatives [19].…”