E. Histolytica

• What does E. histolytica cause?

  Amoebic dysentery: bloody + mucous-y diarrhea
• Where is E. histolytica found?

  Worldwide, mammals are the reservoir hosts
• What stages are parasitic?

  Metacyst Troph. -> Trophozoite
• What stages are free living?

  Precyst -> Cyst -> Metacyst
• Trophozoite stage?

  20 - 30 um

  Spherical Bulls-eye nucleus

  
• Trophozoite stage?

  Food vacuoles in the cytoplasm

  No chromatid bars
• What triggers E. histolytica cyst formation?

  Dehydration of the stool in the lower intestine
• What happens during cyst formation?

  Undigested food is discarded, then is formed into the precyst that has a large glycogen vacuole

  
• How many nuclei does an E. histolytica metacyst have?

  8 nuclei

  
• Where to E. histolytica trophozoites live?

  Mucosa of the lower intestine, forms ulcers and may reach the blood vessels
• E. histolytica ectopic sites?

  Liver, lungs, brain
• What happens if a person with many E. histolytica is releasing a lot of cysts?

  May be asymptomatic
• Pathology?

  90% are a symptomatic
• Pathology?

  10% are symptomatic

  loose stool, stomach pains, and nausea are mild symptoms
• Pathology: severe symptoms?

  amoebic dysentery, ulcers, megacolon, ameboma, ectopic infections, diarrhea
• How can people be with E. histolytica be identified?

  Flask shaped intestinal lesions

  
• What happens to a person with eosinophilia + dysentery?

  formation of Charcot-Layden crystals, eosinophils in stool are disintegrated and crystalized
• Diagnosis of E. histolytica?

  Trophozoites + cysts in stool

  Ectopic infection: x-rays
• How to prevent E. histolytica?

  Proper waste disposal and hygiene

  Fly control