Transfusion products

Occasionally blood, platelets and other transfusion products become contaminated at the time of collection from donors, during processing or at the time of infusion into patients. Any organism isolated must be considered significant.

Setup Both a sample of the transfusion product from the bag and a segment from the tubing should be processed. With aseptic technique, use a needle and syringe to take a sample from each. Enter the order into the LIS twice: one for the tubing and the second for the bag.

Direct examination

Not indicated


From the bag aspirate 20 mL and inoculate aerobic and anaerobic blood culture bottle with approximately 9 mL each. Process as per usual blood culture protocol.

With the remaining blood aspirated from the bag and with the sample retrieved from the segment inoculate:

Media Incubation
Blood Agar (BA) CO2, 35°C x 4 days
Chocolate Agar (CHOC) CO2, 35°C x 4 days

Examine the BA and CHOC plates for growth daily for 4 days.

Interpretation Utilize normal blood culture protocol. Identify all isolates.


Negative Report
No growth

Positive Report
Report all isolates with appropriate susceptibilities.

Do not quantitate except if it is from the fluid medium only – add Comment “From broth culture only, indicative of small numbers and/or contamination.”

Telephone results of all positive Gram stains and cultures to ward / ordering physician.

References P.R. Murray, E.J. Baron, M.A. Pfaller, R.H. Yolken. 2003. Manual of Clinical Microbiology, 8th ed. ASM Press, Washington, D.C.

H.D. Izenberg. 2003. Blood Cultures-General Detection and Interpretation, p. In Clinical Microbiology Procedures Handbook, 2nd ed. Vol.1 ASM Press, Washington, D.C.