|Description:||Under a magnification of 1850X, this PAS-stained (Periodic acid-Schiff) photomicrograph revealed histopathologic changes found in a tissue sample from a case of protothecosis, which is caused by the green algae, Prototheca.|
Though categorized taxonomically as an alga, Prototheca lacks chlorophyll, and therefore, derives its sustenance as a saprophyte, consuming dead and decaying organic matter. Under microscopic analysis, Prototheca spp. resemble a fungal organism, and can therefore, be mistaken when attempting to identify these algae.
Prototheca spp. have been found to cause the disease protothecosis, in animals such as dogs, cats, cattle, and as was the case here, in deer, as well as human beings. An ubiquitous organism, Prototheca spp. are found in soild, and sewerage systems worldwide. Protothecosis occurs in two forms, cutaneous, affecting the skin, and disseminated, or throughout the body. Usually, when a human being is affected, it due to the fact that the individual is immunosurpressed, as it is with AIDS, or undergoing chemotherapy.