BACTERIAL-CONTAMINATION OF AUTOLOGOUS BONE-MARROW DURING PROCESSING

As part of an audit of the processing of autologous bone marrow, we fo und that marrow was often contaminated with organisms potentially path ogenic to neutropenic recipients. One of 14 marrows studied was found to be contaminated before the processing stage and five others became contaminated during processing. The organisms isolated at these stages were Propionibacterium sp., coagulase-negative staphylococci, Staphyl ococcus aureus and coryneforms, suggesting that the skin was the likel y source of contamination. Five out of the 11 marrows returned to pati ents were found to be contaminated after thawing. Two of these were ma rrows previously shown to be contaminated with coagulase-negative stap hylococci before freezing, and from these coagulase-negative staphyloc occi were isolated again, in one case the strains were indistinguishab le. New organisms isolated after thawing included Bacillus sp. and Cor ynebacterium sporogenes suggesting contamination from the environment. No infections attributable to these organisms were demonstrated in an y of the patients studied.