Microsporidium. Microsporidia are obligate intracellular fungi, but have been historically treated as protozoa. Microsporidia are found in the environment and the entire group contains more than 1200 species from more than 100 genera.

1. PHYLUM
MICROSPORA
BY:
SYED HAMAD ALI SHAH
TO;
DR. SHUMILA IRRUM

2. CONTENTS
• Classification
• History
• Morphology
• Life Cycle
• Diseases
• Lab Diagnosis
• Cell Culture
• Treatment

3. CLASSIFICATION
Kingdom: Fungi
Phylum: Microsporidia
Class: Dihaplophasea
Order: Dissociodihaplophasida
Family: Nosematidae
Genus: Nosema

4. HISTORY:
• First protozoans parasites successfully studied and controlled by
Louis Pasture.
• The microsporidia were first recognized as pathogens in silkworms
in 1857, these organisms infect host species ranging from protists
to human, were first associated with human infections in 1924.
• In the 9 genera, 13 species are associated with human diseases.
• Particularly in HIV infected and other immunocompromised
individuals.

5. MORPHOLOGY
• Microsporidia are classified under phylum Microspora
• Minute, Intracellular, Gram positive, Spore forming protozoa
• Genus Coming under Microsporidia
i. Nosema
ii. Microsporidium

6. CONTI…………
• Unicellular, Obligate intracellular parasites
• Reproduce in the host by producing spores(Sporogony)
• Spores are oval to cylindrical in shape with a polar filament or tubule.
• Spores – Infective stage of microsporidia
• Spores – Only stage of life cycle capable of existing outside the host
• Polar tubule – Extrusion mechanism for injecting infective spore contents
into host cell.

7. CONTI…………….
• Spores surrounded by thick double layered cyst wall
i. Outer layer: Exospore (Proteinaceous)
ii. Inner layer: Endospore (Chitinous)
• Spores are gram positive and acid fast

9. LIFE CYCLE
• Infection – Ingestion or inhalation of spores
• In Duodenum – Spores with its nuclear material is injected through polar
tubules into enterocytes
• Multiply by repeated binary fission (Merogony) produce large
number of spores (sporogony)
• During sporogony thick spore wall is formed protection to parasite
• Spores released from host cell and infect other cells

10. DISEASES
• Opportunistic infections in HIV infected and other
immunocompromised host
• HIV infected – Enterocytozoon bienuesi and Encephalitozoon
intestinalis leads to protracted debilitating diarrhea in 10 to 40%
cases
• Enterocytozoon intestinalis – Sinusitis, Cholangitis and
Bronchiolitis
• Pleistophora – Myositis
• Nosema and Microsporidium – Stomal keratitis associated with
truma

11. LAB DIAGNOSIS
• MICROSCOPY:
i. Demonstration of spores in stool, urine, CSF or small intestine
biopsy
ii. Stained with gram’s stain or modified trichome stain
• ELECTRON MICROSCOPE – Gold standard
• DIRECT FLORESCENT METHOD – Using monoclonalantibody

12. CELL CULTURE
• Microsporidia spores can be cultured in monkey and rabbit kidney
cell lines and human fetal lung fibroblast cell lines
MOLECULAR DIAGNOSIS
• PCR

13. TREATMENT
• No specific treatment and effective drug
• Intestinal Microsporidia – Metronidazole and albendazole
• Superficial keratoconjunctivitis – Tropical therapy with Fumagillin
suspension
• PROPHYLAXIS Improved personal hygiene and sanitation
especially in immunocompromised persons can prevent
microsporidia