Balantidium coli, Isospora, Cyclospora,

Cryptosporidia, Microsporidia & Sarcocystis

Dr. R. Someshwaran, MD.,Assistant professor, Dept. of Microbiology,

Karpagam Faculty of Medical Sciences & Research,

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

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.

Balantidium coli

• Pig is the common reservoir host

• Morphology: 2 stages• Trophozoite stage• Encysted stage

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

Balantidium

• Trophozoite stage: Peristome – Groove in Anterior end Cytosome – mouth Cytopharynx – funnel shaped gullet No intestine Cytopyge – Permanent anus

Balantidium coli

• Trophozoite stage: a) Two nuclei (Large kidney shaped macronucleus) b) Two contractile vacuoles c) Many food vacuoles with RBC, WBC, tissue debris

Balantidium

• Cystic stage: Slightly smaller than trophozoite 50-60µm diameter Granular cytoplasm Macronucleus and a refractile body Double layered cyst wall

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

LIFE CYCLE

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

Lab Diagnosis & Treatment

Stool Microscopy: Trophozoites of B. coli

Treatment: a) Tetracycline 500 mg Q.i.d for 10 daysb) Metronidazole 750 mg TDS for 5 daysc) Iodoquinol 650mg TDS for 20 days

Acid fast Intestinal parasites - size

• Isospora belli 20-30 µm• Sarcocystis – 50-60µm• Cyclospora – 40-50µm• Cryptosporidium – 4-6µm• Microsporidium – 1-3 µm

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

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

MICROSPORA

• Enterocytozoon hellam-peritonitis, myositis, keratoconjunctivitis

• Encephalitozoon cuniculi• Encephalitozoon intestinalis or septatata

intestinalis• Treatment:• Albendazole 400mg BD for 4 weeks

MICROSPORA

MICROSPORIDIA

MICROSPORIDIA

MICROSPORIDIA

Cryptosporidiosis

• Disease of birds, reptiles and fishes and also man

• Cryptosporidium parvum• Acid fast - MZN

Cryptosporidium parvum LIFE cycle

Cryptosporidium spp., - Acid fast- MZN

Cryptosporidium spp.,

Cystoisospora belli

Isospora

Isospora

Isospora

Cyclospora cayatensis

Cyclospora life cycle

Cyclospora cayatenesis

Cyclospora cayatenesis

Cyclospora cayatenesis

Cyclospora cayatenesis

• Treatment: • Co-trimoxazole 160/800mg BD for 7 days

Sarcocystis hominis, S. suihominis

• Sarcocystosis• Intestinal sarcocystosis• Cyst in the muscle (Muscular cyst)• Acid fast by MZN• Man- definitive host• Pig – intermediate host

Sarcocystis

Sarcocystis

Take home message & Summary

• Acid fast Intestinal parasites• Persistent diarrhoea – HIV/AIDS• Cryptosporidium spp., - Oocyst• Cyclospora spp., - Oocyst• Isospora spp., - Oocyst• Sarcocystis spp., - Oocyst• Microsporidium spp., - Spores• Balantidium coli- Largest intestinal ciliated

protozoan