microsporidia-14
DESCRIPTION
protozoa ususTRANSCRIPT
21/04/2023Even Semester 2014
MICROSPORIDIA
Microsporidia
are unicellular obligate intracellular have been recognized as causing
disease in animals recognized as agents of human
disease in the mid 1980s (AIDS pandemic ).
Currently, 15 microsporidian species have been identified in man, of which most, but not all, are associated with HIV infection
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Family Genera
Species
Nosematidea Brachiola B. algerae, B. vesicularum
Encephalitozoonidea EncephalitozoonE. cuniculi, E. hellem, E. intestinalis (syn. Septata intestinalis).
Enterocytozoonidea Enterocytozoon Enterocytozoon bieneusi,
Microsporidea Microsporidium M. ceylonensis, M. africanumNosematidea Nosema N. ocularum, N. connori (syn. B connori)Pleistophoridea Pleistophora Sp.
Pleistophoridea Trachipleistophora T. hominis, T. anthropophthera,
Nosematidea Vittaforma Vittaforma corneae (syn. Nosema corneum)
Lily Cheng '06, [email protected] (Stanford University)
Morphology small, ranging from 1.5 - 2.5 mm x
2.5 - 4 mm. oval to cylindrical and possess a thick double-layered
spore wall The life cycle includes repeated
divisions by asexual ( schizogoni) and spore production (sporogony).
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Life cycle
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Source: DR Arora1, B Arora2
Indian Journal of Medical Microbiology, Vol. 27, No. 3, July-September, 2009.
Pathogenesis and Clinical Symptoms Intestinal microsporidiosis is the
most common infection caused mainly by Enterocytozoon bieneusi and Encephalitozoon intestinalis
Enterocytozoon bieneusi is normally restricted to the small intestinal enterocytes whereas E. intestinalis spreads into the lamina propria.
These 2 species have been found to spread from the intestine along the epithelium to the gall bladder and the pancreatic and bile ducts.
It produces persistent diarrhea
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Transmission electron micrograph of a microsporidian spore with an extruded polar tubule inserted into a eukaryotic cell.
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Diagnosis Detection of spores in the stool
samples and the contents of the duodenum-jejunum : by staining with modified trichrome
stain, Giemsa or fluorescent dyes. Electron microscopy (EM) is the
"gold standard" for confirming infection and attempting to classify the organisms seen in tissues
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Encephalitozoon intestinalis
stained with Calcofluor white (CDC)
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Scanning electron micrograph of a microsporidian spore with an extruded polar tubule inserted into a eukaryotic cell. The spore injects the infective sporoplasms through its polar tubule.
Prevention
precautions when handling body fluids and personal hygiene measures : such as hand washing may be important in preventing primary infections in health care settings.