THE USE OF A CHEMILUMINESCENCE-LINKED UNIVERSAL BACTERIAL RIBOSOMAL-RNA GENE PROBE AND BLOOD-GAS ANALYSIS FOR THE RAPID DETECTION OF BACTERIAL-CONTAMINATION IN WHITE CELL-REDUCED AND NONREDUCED PLATELETS

Because of the rising incidence of bacterial growth and septic platelet transfusions in aging units, platelet storage is currently limited in the United States to 5 days. This approved shelf life of platelets might be altered if methods were devised to rapidly detect infected units and/or to decrease the incidence of bacterially contaminated platelets. An investigation was conducted on the eff ect of a prototype blood collection system with an in-line filter for the production of white cell-reduced platelet-rich plasma on the growth of bacteria in platelets prepared from whole blood that had been inoculated with Staphylococcus epidermidis. Additional studies were conducted with a chemiluminescence-linked ribosomal RNA (rRNA) gene probe and with blood gas analysis to identify possible methods for the rapid detection of bacterial contamination. All units were followed for 9 days of storage. The filtration of the platelet-rich plasma resulted in an approximate 2 log10 reduction in white cells with an average loss of 6.7 percent of platelets. Filtration did not appear to alter bacterial growth. In all platelet units that supported growth, pO2 dropped to negligible values and pCO2 rose relative to culture-negative units. The changes were most sensitive and specific beyond 5 days of storage. The universal bacterial rRNA probe assay was able to detect S. epidermidis in concentrations as low as 1 x 10(3) colony-forming units per mL in some cases and reliably detected all units contaminated at a concentration of 1 X 10(4) Colony-forming units per mL. The use of this probe for the testing of older (or all) platelet units (pooled, individual, or apheresis) could lead to a decrease in the incidence of septic platelet transfusion reactions and possibly to an increase in the acceptable storage period of platelets.