A colleague in Ohio would like to know how what techniques/methods are used by others for fungal cultures of Hematopoietic Progenitor Cells, Apheresis (HPC-A), or Marrow (HPC-M), as well as the frequency of and reasons for this testing. Currently, his hospital does NOT perform routine fungal cultures on every product (based on the results of internal quality audits), but they do an occasional culture for adverse reaction investigations, the results of which take up to 28 days for a final report. When they do fungal cultures for adverse reaction workups, the samples are inoculated directly onto primary isolation media for culture confirmation of the suspected etiologic agent without pretreatment. Four different kinds of primary isolation media are used for the recovery of fungi from clinical specimens:

• Potato flake agar (PFA): Used for the general support of fungal growth.
• Inhibitory mold agar (IMA): Mildly selective medium containing gentamicin and chloramphenicol to inhibit bacterial growth
• Mycobiotic agar (MYB): Selective medium containing chloramphenicol and cycloheximide to inhibit growth of contaminating bacteria and saprophytic fungi.
• Yeast extract phosphate (YXP): Made selective with the addition of ammonium hydroxide. Inhibits bacteria, yeast, and most saprophytic fungi and is used for the recovery of dimorphic pathogenic fungi.

The HPC-A and HPC-M are plated by placing 2-3 parallel inoculum lines across the surface of PFA, IMA, MYB and YXP plates and counterstreaking the surface of all plates.

The following comments have been received.

ADDENDA Sept. 20, 2005

1. The Editor suggests that colleagues interested in this discussion should review the information at Experience with Positive Cultures of Hematopoietic Stem Cell Components.

ADDENDA Sept. 22, 2005

2. A quality assurance specialist from the East Coast comments that he advises any facility deciding on a sterility assay policy for their HPC or Cellular Therapy products to first determine if their product is regulated under Section 351 of the Public Health Service Act or under Section 361 of the same act, HRSA or under IND. He cautions that this is critical because the pathway of regulation is different for each. He states "HRSA products (bone marrows not under Section 351 of the PHS Act or IND) do not have clearly defined requirements or exclusions for sterility assay. IND products are subject to 21 CFR 312 rules and are usually held to the cGMP requirements for biological products other than blood. Phase 1, IND trials have patient safety as the number one concern and sterility is a key issue for the FDA. Products that are covered solely under Section 361 of the PHS Act are governed under 21 CFR 2171 and you are required to demonstrate that you have minimized the risk of spread of communicable disease. Section 351 PHS act products (Biological Products) are held to the cGMPs and must use a sterility method compliant with USP 71 or 21CFR 610.12 or other validated equivalent. The type of product does not dictate the which regulation applies, but rather the intended use, the final product and sometimes the manufacturing process determines which regulatory statute for sterility assay applies". He concludes saying that there are several consultants to help sort this out and expects that there may be FDA guidance on the way.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator