Microbial contamination of peripheral blood stem cell collections

We prospectively evaluated microbiologic cultures for a series of 1263 peripheral blood stem cell harvests collected from 376 sequential patients, The incidence of microbial contamination was 0.23% of all samples, or 0.47% of samples from patients not receiving systemic antibiotics, This incidence of positive microbial cultures is less than that for cultures of bone marrow (3.8%) after harvesting and before further processing, Of the three positive cultures, two grew coagulase-negative Staphylococcus and the third, Streptococcus viridans. Two patients were reinfused with culture-positive PBSC components, and neither exhibited the same organism in subsequent blood cultures, Although microbial contamination may occur during peripheral blood stem cell collection and cryopreservation, this report indicates that PBSC contamination does not play a conspicuous role in the infectious complications of PBSC transplantation.