The organism identified as being present within a specimen sample. "Organism" as used here is not the full spectrum of possible living things, but rather is limited to a member of the following: Bacteria, Fungus, Mycobacterium, Parasite, or Virus. Note that some organisms, primarily parasites, may undergo different stages over their lifetime (e.g., eggs, larvae, adults), which is indicated in the optional lifeStage property. Some terminologies will pre-coordinate the organismTaxon and stage into a single code (Giardia lamblia cysts, Giardia lamblia trophozoites).