Amoeba Parasitology

Amoeba Parasitology

Definition and Classification

• Amoebas are single-celled eukaryotic organisms belonging to the kingdom Protista
• Classified into two main groups:
  • Free-living amoebas: Found in soil, freshwater, and saltwater environments
  • Parasitic amoebas: Infect and live within host organisms, including humans

Parasitic Amoebas

• Entamoeba histolytica: Most common parasitic amoeba, causing amoebic dysentery and amoebic liver abscess
  • Infects approximately 50 million people worldwide
  • Transmission: Fecal-oral route, contaminated water, and food
• Acanthamoeba: Causes acanthamoebiasis, a rare but potentially fatal infection
  • Infects the eye, brain, and skin
  • Transmission: Contact lens use, contaminated water, and soil
• Balamuthia mandrillaris: Causes balamuthiasis, a rare and often fatal infection
  • Infects the brain and skin
  • Transmission: Unknown, but suspected to be through contaminated soil and water

Life Cycle

• Trofozoite stage: Active, motile stage that invades host cells
• Cyst stage: Dormant, resistant stage that can survive outside the host
  • Excystation: Process of cysts transforming into trophozoites
  • Encystation: Process of trophozoites forming cysts

Pathogenesis and Symptoms

• Entamoeba histolytica:
  • Causes intestinal ulcers, diarrhea, and abdominal pain
  • Can lead to amoebic liver abscess, a life-threatening condition
• Acanthamoeba:
  • Causes keratitis (eye infection), granulomatous amoebic encephalitis (brain infection), and skin lesions
• Balamuthia mandrillaris:
  • Causes granulomatous amoebic meningoencephalitis (brain infection) and skin lesions

Diagnosis and Treatment

• Microscopy: Identification of amoebas in stool, tissue, or cerebrospinal fluid samples
• Antibodies: Detection of anti-amoeba antibodies in serum or cerebrospinal fluid
• Antimicrobials: Metronidazole, tinidazole, and chloroquine used to treat amoebic infections

Learn about the definition, classification, and life cycle of amoebas, as well as the pathogenesis and symptoms of parasitic amoebas like Entamoeba histolytica, Acanthamoeba, and Balamuthia mandrillaris. Understand the diagnosis and treatment of amoebic infections.