Bacterial contamination of autologous bone marrow during processing

Area of Science:

• Microbiology
• Hematology
• Transplantation Science

Background:

• Autologous bone marrow transplantation is a critical therapy.
• Ensuring the sterility of processed bone marrow is vital for patient safety, especially for immunocompromised individuals.

Purpose of the Study:

• To audit the processing of autologous bone marrow for microbial contamination.
• To identify the sources and types of contaminating organisms.
• To assess the clinical relevance of detected contamination.

Main Methods:

• Audit of autologous bone marrow processing stages.
• Microbial culture and identification of organisms.
• Comparison of isolates before processing, during processing, and after thawing.
• Clinical review of patient outcomes.

Main Results:

• One of 14 marrows was contaminated pre-processing; five became contaminated during processing, likely from skin flora (Propionibacterium sp., coagulase-negative staphylococci, S. aureus, coryneforms).
• Five of 11 post-thaw marrows were contaminated, with some showing persistent coagulase-negative staphylococci and new environmental contaminants (Bacillus sp., Corynebacterium sporogenes).
• No infections were clinically attributed to the isolated microorganisms in the studied patients.

Conclusions:

• Autologous bone marrow processing presents risks of microbial contamination from both patient skin and the environment.
• Current processing methods may require enhanced aseptic techniques to minimize contamination.
• Despite detected contamination, clinical outcomes in this cohort were not adversely affected.