1. Balantidium coli,
Isospora, Cyclospora, Cryptosporidia,
Microsporidia & Sarcocystis
Dr. R. Someshwaran, MD.,Assistant professor,
Dept. of Microbiology,
Karpagam Faculty of Medical Sciences & Research,
2. OBJECTIVES
To define etiology, morphology, life cycle,
disease caused, laboratory diagnosis and
treatment of Acid fast Intestinal parasitic
infections caused by Isospora, Cyclospora,
Cryptosporidia, Microsporidia and Sarcocystis
spp.,
To define etiology, morphology, life cycle,
disease caused, laboratory diagnosis and
treatment of Balantidium coli infections
3. Balantidium
• Large protozoal parasite
• Phylum: Ciliophora
• Body covered with cilia (hair-like process)
• Two morphologically distinct nuclei
• Balantidium coli - pathogenic to human beings
• World wide in distribution
• Habitat: Large intestine of Humans
• Also seen in Pigs & Monkeys.
4. Balantidium coli
• Pig is the common
reservoir host
• Morphology:
2 stages
• Trophozoite stage
• Encysted stage
5. Balantidium coli
• Trophozoite stage:
Found in dysenteric stool
Oval body, variable size
60-70µm X 40-50µm
Body covered with delicate pellicle
Cilia – short and delicate
Adoral cilia – around mouth
7. Balantidium coli
• Trophozoite stage:
a) Two nuclei (Large kidney shaped
macronucleus)
b) Two contractile vacuoles
c) Many food vacuoles with RBC,
WBC, tissue debris
8. Balantidium
• Cystic stage:
Slightly smaller than trophozoite
50-60µm diameter
Granular cytoplasm
Macronucleus and a refractile body
Double layered cyst wall
9. LIFE CYCLE
• Infective form: Mature Cyst
• Mode: Feco-oral contamination by ingestion
of food, water, among food handlers
• Life cycle in 2 stages (both inside the host)
• Natural host – Man
• Amplifier host / Reservoir host – Pig
• Pig-Pig, Man-Man, Pig-Man, Man-pig
11. Pathogenesis
• Cyst – Trophozoite in Large intestine
• Lumen to Submucous coat – where it
multiplies by binary transverse fission
• Micronucleus – 2 macronuclei
• Conjugation between 2 trophozoites
• Starchy food – abundant in Pig’s intestine
• Parasite does not invade liver
12. Lab Diagnosis & Treatment
Stool Microscopy:
Trophozoites of B. coli
Treatment:
a) Tetracycline 500 mg Q.i.d for 10 days
b) Metronidazole 750 mg TDS for 5 days
c) Iodoquinol 650mg TDS for 20 days
14. MICROSPORA
• Microsporidia
• 7 genera
• Enterocytozoon (E.bieneusi, E.intestinalis),
Encephalitozoon, Nosema, Pleistophora,
Thelohanea, Trachipleistophora & Vittaforma
• Causes microsporidiosis especially in AIDS
cases causing persistent diarrhoea, abdominal
cramps, nausea, malabsorption
15. MICROSPORA
• Microsporidia – minute unicellular obligate
intracellular spore forming protozoa
• Life cycle: not worked out fully
• 2 developmental stages inside a host cell
• i) Schizogony, ii) sporogony
• Spore –polar tube – sporoplasm – enterocytes –
merogony – several spore formed
• Size of spore less than 10µm in length
• Spores- Oval or cylindrical – Acid fast by MZN