Applications of real-time PCR in the screening of platelet concentrates for bacterial contamination

Abstract

Although there have been major improvements over the past few decades in detection methods for blood-borne infectious agents, platelet concentrates are still responsible for most cases of transfusion-transmitted bacterial infections. To date, real-time PCR is an indispensable tool in diagnostic laboratories to detect pathogens in a variety of biological samples. In this article, the applications of this powerful technique in the screening of platelet concentrates for bacterial contamination are discussed. Next to pathogen-specific (real-time) PCR assays, particular attention is directed to the recently developed 16S rDNA real-time PCR. This assay has been proven as a convenient way to detect bacterial contamination of platelet concentrates. The assay is sensitive and enables rapid detection of low initial numbers of bacteria in platelet concentrates. The short turnaround time of this assay allows high-throughput screening and reduction of the risk of transfusion of bacterially contaminated units. As with every method, real-time PCR has its advantages and disadvantages. These and especially limitations inherent to generation of false-positive or -negative results are emphasized. The universal nature of detection of the assay may be suitable for generalized bacterial screening of other blood components, such as red blood cells and plasma. Therefore, it is necessary to adapt and optimize detection in red blood cells and plasma with real-time PCR. Further sophistication, miniaturization and standardization of extraction and amplification methods should improve the total performance and robustness of the assay. Hence, real-time PCR is an attractive method in development as a more rapid screening test than currently used culture methods to detect bacterial contamination in blood components.