Comparison of Sensitivity of Tests for Detecting Bacterial Contamination in Platelet Concentrates / 대한수혈학회지

ABSTRACT

BACKGROUND: The demand for platelet concentrates has increased for patients with hemato-oncologic diseases as well as for patients with chronic diseases. As platelet concentrates are preserved at 22~24degrees C, the chance of bacterial contamination exposure is increased, which can cause fatal outcomes. We evaluated various methods for detecting bacterial contamination in platelet concentrates. METHODS: 0.5 MacFarland standard solutions were prepared using the Staphylococcus aureus ATCC 25923 & Escherichia coli ATCC25922 strains. The platelet concentrates were inoculated with various concentrations (10(1)~10(5) CFU/mL) of bacteria and then gram staining, plate culture, broth culture and 16s RNA were used to detect bacteria. RESULTS: The gram stain method was unable to detect bacteria concentrations less than 10(4) CFU/mL. The plate culture method detected bacterial growth concentrations up to 10(3) CFU/mL, but only 1 specimen of S. aureus was detected at the lowest concentration of 10(1) CFU/mL. The broth culture method detected 10(2) CFU/mL concentrations except for samples from S. aureus and E. coli strains. Among the 10(1) CFU/mL lowest concentrations, bacterial growth detected 3 samples from S. aureus and 2 samples from E. coli. For the broth culture method, detection of bacterial growth up to 10(1) CFU/mL took 58.9 hours, it took 57.5 hours for S. aureus and E. coli respectively, and it took 43.9 hours and 49.0 hours for 10(2) CFU/mL concentrations of S. aureus and E. coli, respectively. The PCR method showed all positive results except for 1 specimen of E. coli. CONCLUSION: The broth culture method showed similar sensitivity to PCR except for the 43.9~58.9 hours of an incubation period to show positive RESULTS. Overall, the PCR method was most sensitive and rapid method for detecting bacterial contamination in platelet concentrates.