Removal of Yersinia enterocolitica from AS-1 red cells

The growth of Yersinia enterocolitica in AS-1 red cells was investigated so as to study the organism's proliferation kinetics and to evaluate the effect of prestorage white cell (WBC) reduction on bacterial multiplication. Twenty-four 2-unit pools of ABO-compatible whole blood were prepared and inoculated with Y. enterocolitica to final concentrations ranging from 0.3 to 132 organisms per mL. After inoculation, pools were split equally, AS-1 red cells were prepared, and 1 unit of each pair (test unit) was WBC-reduced with a WBC-reduction filter. Quantitative bacterial cultures of both WBC-reduced and control units were performed at several points throughout preparation and storage. Less than 10 percent of the inoculated organisms was recovered from blood samples taken after a 7-hour room-temperature holding period. By the end of 42 days of storage, Y. enterocolitica was recovered from unfiltered red cells in 2 of the 6 units inoculated at the lowest levels (0.3 and 0.7 organism/mL), from 8 of the 12 units inoculated at the intermediate levels (2.8, 5.2, 30.7, and 43 organisms/mL) and from 6 of the 6 units inoculated at the highest levels (98.8 and 132 organisms/mL). Positive cultures were seen as early as Day 7. In contrast, filtered units inoculated at all levels less than or equal to 98.8 organisms per mL (21/21 units) were sterile at the end of the 42-day storage period, while 2 units (2/3) inoculated at 132 organisms per mL showed growth despite filtration.(ABSTRACT TRUNCATED AT 250 WORDS)