Intestinal Protozoans II: Balantidium coli & Entamoeba histolytica

Balantidium coli & Entamoeba histolytica

What is the causative agent of Balantidiasis?

Balantidium coli

What is the distribution of B. coli?

Worldwide; higher in areas with pigs and poor sanitation

What is the taxonomic classification of B. coli?

Phylum Ciliophora

What is the route of transmission of B. coli?

Ingestion of water, food, etc. contaminated with B. coli cysts

Define the progression of cysts in B. coli’s life cycle?

Ingested → Travel to small intestine → Excystation (one cyst releases one trophozoite into large intestine)

Define the progression of trophozites in B. coli’s life cycle?

1. Binary Fission (asexual reproduction)

2. Conjugation (sexual reproduction)

3. Encystation

4. Invasion of colon → asexual reproduction → ulcer

5. Remain in large intestine

Explain what happens when a trophozoite undergoes encystation.

They revert back to their dormant, infectious stage, and the cysts are later released in stool

What are the reservoir hosts of B. coli?

Pigs

What are symptoms associated with Balantidiasis?

• Incubation period 3-4 days

• Asymptomatic

• GI issues:

  • Dysentery: diarrhea (may or may not be bloody), abdominal pain, fever, cramps, general malaise

  • Ulcers, intestinal perforation

• Severe/fatal in immunocompromised people

How would you diagnose Balantidiasis?

Microscopy - visualization in feces or tissue from endoscopy

How would you treat Balantidiasis?

• Fluids - drinking and IV

• Antiprotozoals and antibiotics

What is the causative agent of Intestinal amebiasis?

Entamoeba histolytica

What is the taxonomic classification of Entamoeba histolytica?

Phylum Amoebozoa

What is the distribution of E. histolytica?

Worldwide; higher in areas with poor sanitation

What is the route of transmission of E. histolytica?

Ingestion of water, food, etc. contaminated with E. histolytica cysts

Describe the progression of trophozoites in E. histolytica’s life cycle, once the reach the large intestine.

1. Stay in large intestine

2. Invade intestinal mucosa

3. nvade blood vessels and reach other organs

What happens after trophozoites undergo asexual reproduction?

They go through encystation, and the cyst and the trophozoites are released in feces. Only the cysts are infectious and they can survive for days to weeks.

What are symptoms associated with Intestinal amebiasis?

• Incubation period 2-4 weeks

• Asymptomatic

• Amebic colitis when intestinal mucosa invaded

• GI issues:

  • Dysentery: diarrhea (may or may not be bloody), abdominal pain, fever, cramps, general malaise

  • Can be severe

• Chronic - peritonitis, perforations, amebic granulomas

How would you diagnose Intestinal amebiasis?

• Microscopy - visualization in feces or tissue from endoscopy

• Serology

• PCR