Biology:Trypanosoma vivax

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Short description: Protozoan parasite, cause of nagana

Trypanosoma vivax
Scientific classification edit
Domain: Eukaryota
Phylum: Euglenozoa
Class: Kinetoplastea
Order: Trypanosomatida
Family: Trypanosomatidae
Genus: Trypanosoma
Species:
T. vivax
Binomial name
Trypanosoma vivax
Ziemann, 1905
Synonyms
  • Trypanosoma caprae
  • Trypanosoma angolense
  • Trypanosoma (subg. Duttonella) vivax[1][2]

Trypanosoma vivax is a parasite species in the genus Trypanosoma. It causes the disease nagana, affecting cattle or wild mammals. It is mainly occurs in West Africa, although it has spread to South America.[3][1]

Range

Historically restricted to sub-Saharan Africa especially West Africa, it has spread to 13 countries of South America. This has been made easier by its mechanical transmission route, see § Life cycle below.[1]

Hosts

Hosts include, cattle, horses, sheep, and camels.[2][1] (As of 2016) in South America it is an emerging pathogen of cattle, and sometimes horses and other ruminants.[1]

The vector host is Glossina.

Life cycle

Unusual for a trypanosome, T. vivax does not infect the Glossina vector midgut. Instead it infects and completes an abbreviated life cycle only in the vector's proboscis. Thus it is entirely mechanically transmitted. For this reason it has had a relatively easy time jumping vectors, and thereby even jumping geographic ranges which do not have its customary vector.[1]

Symptoms

Symptoms of T. vivax include "rapid weight loss, lethargy, weakness, clumsiness, pale mucosa, swelling of superficial lymph nodes, anemia, and fluctuating pyrexia, causing[...]a drop in animal productivity."[4]

Enzymes

A novel proline racemase of medical and veterinary importance has been described in T. vivax (B8LFE4).[5]

It also produces vivapain, a cysteine peptidase.[6]

Host immunity

The smallest variable surface glycoprotein (40 kDa in size) to date has been found in T. vivax, which bears little carbohydrate.[7]

Economic impact

Trypanosoma vivax is a significant drag on Africa's cattle production every year, and increasingly is a concern in South America: One outbreak in 1995 in the Pantanal in Brazil and Bolivia cost the industry over US$160 million.[1]

Trypanocide resistance

Some resistance to trypanocides has been observed: Some African countries have isometamidium-resistant populations, with some of these also being resistant to diminazene. (This has been ascribed variously to cross-resistance or to two separate events of acquisition of separate resistance genetics. Isometamidium and diminazene are not thought to be in the same trypanocide class.) Resistance to both is widespread in both West and East Africa. Diminazene resistance has been observed in South America.[1]

Mechanisms of resistance are not necessarily shared across the genus, and this is especially true for this, the most genetically divergent species.[1]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 Giordani, Federica; Morrison, Liam J.; Rowan, Timothy G.; De Koning, Harry P.; Barrett, Michael P. (2016-10-10). "The animal trypanosomiases and their chemotherapy: a review". Parasitology (Cambridge University Press (CUP)) 143 (14): 1862–1889. doi:10.1017/s0031182016001268. ISSN 0031-1820. PMID 27719692. 
  2. 2.0 2.1 Osório, Ana Luiza Alves Rosa; Madruga, Claudio Roberto; Desquesnes, Marc; Soares, Cleber Oliveira; Ribeiro, Laura Raquel Rios; Costa, Sylvio Celso Gonçalves da (2008). "Trypanosoma (Duttonella) vivax: its biology, epidemiology, pathogenesis, and introduction in the New World - A Review". Memórias do Instituto Oswaldo Cruz (FapUNIFESP (SciELO)) 103 (1): 1–13. doi:10.1590/s0074-02762008000100001. ISSN 0074-0276. PMID 18368231. 
  3. "Association of Trypanosoma vivax in extracellular sites with central nervous system lesions and changes in cerebrospinal fluid in experimentally infected goats". Veterinary Research 42 (63): 1–7. 2011. doi:10.1186/1297-9716-42-63. PMID 21569364. 
  4. Camejo, María; Spencer, Lilian; Núñez, Armando (15 December 2014). "TNF-alpha in bulls experimentally infected with Trypanosoma vivax: A pilot study". Veterinary Immunology and Immunopathology 162 (3–4): 192–197. doi:10.1016/j.vetimm.2014.10.010. PMID 25464824. 
  5. "Proline racemases are conserved mitogens: characterization of a Trypanosoma vivax proline racemase". Mol. Biochem. Parasitol. 165 (2): 170–9. June 2009. doi:10.1016/j.molbiopara.2009.02.002. PMID 19428664. 
  6. Pandey, Kailash (2011). "Centenary celebrations article". Journal of Parasitic Diseases (Springer Science and Business Media LLC) 35 (2): 94–103. doi:10.1007/s12639-011-0084-x. Indian Society for Parasitology. ISSN 0971-7196. PMID 23024488. 
  7. Gardiner, Peter R.; Nene, Vishvanath; Barry, Michele M.; Thatthi, Ravi; Burleigh, Barbara; Clarke, Michael W. (1996). "Characterization of a small variable surface glycoprotein from Trypanosoma vivax". Molecular and Biochemical Parasitology 82 (1): 1–11. doi:10.1016/0166-6851(96)02687-4. PMID 8943146. 

External links

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"Trypanosoma vivax". National Center for Biotechnology Information (NCBI). https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=5699.  Wikidata ☰ Q2456810 entry