GENUS TRYPANOSOMA Flashcards
Trypanosoma
✓ Flagellate protozoan parasites that live in the blood, lymph and various tissues of their vertebrate hosts
✓ parasites of all vertebrate classes
✓ majority are transmitted by blood-feeding invertebrates, although other transmission mechanisms exist
Genus Trypanosoma under Subgenus NANNOMONAS
T. congolense and T. simiae
Genus Trypanosoma under Subgenus DUTTONELA
T. vivax
Genus Trypanosoma under Subgenus MEGATRYPANUM
T. theileri and T. melophagium
Genus Trypanosoma under Subgenus TRYPANOZOON
T. brucei brucei, T. brucei gambiense, T. brucei rhodesiense, T. equinum, T. evansi and T. equiperdum
2-3um Leishmania amastigote maybe the smallest eukaryotic cells
Amastigote
flagellum is very short, projecting only slightly beyond the flagellar pocket
Amastigote
elongated body with flagellum extending forward as a functional organelle
Promastigote
kinetosome and kinetoplast are located in front of the mucleus, near the anterior end of the body
Promastigote
Kinetoplast and kinetosome are still located between the nucleus and the anterior end, but a short undulating membrane lies along the proximal part of the flagellum
Epimastigote (Crithidial)
Kinetoplast and kinetosome are near to the posterior end of the body
Trypomastigote (trypanosome)
flagellum runs along the surface, usually continuing as a free whip anterior to the body
Trypomastigote (trypanosome)
Two broad groups of Trypanosomes
✓ Hemoflagellates
✓ Mucoflagellates
blood and tissue parasites
Hemoflagellates
live in the mouth and the cecum/colon
Mucoflagellates
Two broad groups of Trypanosomes
✓ Salivaria
✓ Stercoraria
develops at the anterior portions of the digestive tract (anterior station)
Salivaria
Example of Salivaria
T. brucei ssp., T. evansi, T. congolense, T. vivax
develop at the vectors hindgut (posterior station)
Stercoraria
Example of Stercoraria
T. cruzi, T. lewisi, T. theileri, T. melophagium, T. canorini
do not require development in an intermediate host
Trypanosoma equiperdum and T. equinum
Salivarian Trypanosome
Fly takes in the trypanosome by feeding- Develops into infective form in the salivary glands- Infective form transferred to animal by feeding
Stercorarian Trypanosome
Fly takes in the trypanosome by feeding- Trypanosome develops into infective form in the rectum- Infective form transferred to another animal through feces
Modes of Transmission of Trypanosomes
• Cyclical
• Non-cyclical
• Coitus
• Transplacental
• Ingestion of fresg carcasses or organs of animals which died of the infection intrauterine
anterior station development; multiplication and transformation in the gut and proboscis; transmission is by feeding
Salivaria
posterior station development; multiplication in the gut; infective forms migrate to the rectum and passed out in the feces
Stercoraria
mechanical transmission by TABANIDS and STOMOXYS; no cross transmission because trypanosomes die quickly
Noncyclical
arthropod intermediate host (biological)
Cyclical
Pathogenesis of Trypanosomes
✓ Lymphoid enlargement
✓ Hemolysis
✓ Cell degeneration and inflammatory infiltrate
exhaustion of cellular elements
lymphoid enlargement
failure of phagocytic system
Hemolysis
tissue degeneratiom particularly the CNS and the heart muscles
Cell degeneration and inflammatory infiltrate
Determines the spread of Trypanosomiasis
• Distribution of vectors
• Virulence
• Host preference