Performance and suitability of polymerase chain reaction for early detection of bacteria in platelet concentrates

BACKGROUND: In this study the applicability of a 16S rRNA real‐time reverse transcriptase polymerase chain reaction (RT‐PCR) and a Staphylococcus genus–specific PCR for screening of bacterial contamination in platelet concentrates (PCs) was determined. STUDY DESIGN AND METHODS: A total of 336 sample bags, from PCs that were routinely tested in the BacT/ALERT (bioMérieux), were collected and frozen until testing by the PCR assays. Based on the BacT/ALERT results, 107 PCs were positive and 229 were negative for bacterial growth. RESULTS: The analytical sensitivity of the 16S rRNA real‐time RT‐PCR ranged from 5 to 40 colony‐forming units (CFUs)/mL. The PCR detected five positive samples, four of which were also positive in the BacT/ALERT. The sensitivity of the test was 3.8%, and the specificity was 99.5%. The analytical sensitivity of the Staphylococcus genus–specific PCR ranged from 5 to 15 CFUs/mL. Thirty‐nine units that were BacT/ALERT positive for staphylococci were tested with this PCR. Six samples were positive with the PCR, five of which were also BacT/ALERT positive. The sensitivity of the Staphylococcus genus–specific PCR was 12.8%, and the specificity was 98.8%. CONCLUSION: Despite the rapid availability of results compared to the BacT/ALERT, the analytical sensitivity of a generic or specific PCR assay is not high enough to be an alternative for the BacT/ALERT when PCs are screened on the day of production.