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The mycology laboratory at TDSHS
receives referred cultures of yeast, mold, and aerobic actinomycetes
from other laboratories for identification. Identification of mycology
cultures is based upon macroscopic and microscopic morphology and
characteristics as well as reactions to a panel of biochemical tests.
Identification of most molds relies heavily on microscopic morphology.
Yeast identification relies on biochemical reactions as well as
microscopic characteristics. Turnaround time for most referred cultures
ranges from two weeks up to four weeks, depending upon the number of
tests required for identification.
Aerobic actinomycete cultures are
subcultured to a panel of biochemical tests that requires three weeks
to result. All aerobic actinomycetes are analyzed by high performance
liquid chromatography (HPLC). The HPLC test on aerobic actinomycetes
indicates whether an organism produces mycolic acids, such as Nocardia species. The HPLC is not species specific but is often useful as an aid to determine the correct genus of the organism.
The genetic probe test utilized for Mycobacterium
species is also utilized for three systemic fungi. It is the same test
described under Genetic Probes. The three systemic fungi identified by
the genetic probe test are Coccidioides immitis, Histoplasma capsulatum and Blastomyces dermatitidis.
Fungal cultures can be submitted for identification on solid media in
tightly capped tubes. Shipping plated medium supporting growth of
molds is highly discouraged.