Trypanosoma
Trypanosoma | |
---|---|
Trypanosoma sp. among red blood cells. | |
Scientific classification | |
Domain: | Eukaryota |
Phylum: | Euglenozoa |
Class: | Kinetoplastea |
Order: | Trypanosomatida |
Family: | Trypanosomatidae |
Genus: | Trypanosoma Gruby, 1843 |
Subgenera | |
| |
Synonyms | |
|
Trypanosoma is a
Trypanosomes infect a variety of hosts and cause various diseases, including the fatal human diseases sleeping sickness, caused by Trypanosoma brucei, and Chagas disease, caused by Trypanosoma cruzi.
The mitochondrial genome of the Trypanosoma, as well as of other kinetoplastids, known as the kinetoplast, is made up of a highly complex series of catenated circles and minicircles and requires a cohort of proteins for organisation during cell division.
History
In 1841,
The genus (T. sanguinis) was named by Gruby in 1843, after parasites in the blood of frogs.[6]
In 1903, David Bruce identified the protozoan parasite and the tsetse fly vector of African trypanosomiasis.[7]
Taxonomy
A number of different methods demonstrate that the traditional Trypanosoma genus is not monophyletic, with the biflagellate Bodonida nested within. The American and African trypanosomes constitute distinct clades, implying that the major human disease agents T. cruzi (cause of Chagas’ disease) and T. brucei (cause of African sleeping sickness) are not closely related to each other.[8]
Phylogenetic analyses suggest an ancient split between a branch containing all Salivarian trypanosomes and a branch containing all non-Salivarian lineages. The latter branch in turn splits into a clade containing bird, reptilian and the Stercorarian trypanosomes infecting mammals, and a clade with a branch of fish trypanosomes and a branch of reptilian or amphibian lineages.[9]
Salivarians are trypanosomes of the subgenera of
Stercorians are trypanosomes passed to the recipient in the feces of insects from the subfamily Triatominae (most importantly Triatoma infestans).[13] This group includes Trypanosoma cruzi, T. lewisi, T. melophagium, T. nabiasi, T. rangeli, T. theileri, T. theodori.[14] The subgenus Herpetosoma contains the species T. lewisi.
The subgenus Schizotrypanum contains T. cruzi[12] and a number of bat trypanosomes. The bat species include Trypanosoma cruzi marinkellei, Trypanosoma dionisii, Trypanosoma erneyi, Trypanosoma livingstonei and Trypanosoma wauwau. Other related species include Trypanosoma conorhini and Trypanosoma rangeli.[citation needed]
Evolution
The ancestor of modern trypanosomes absorbed a
The relationships between the species have not been worked out to date. It has been suggested that T. evansi arose from a clone of T. equiperdum which lost its maxicircles.[16] It has also been proposed that T. evansi should be classified as a subspecies of T. brucei.[17]
It has been shown that T. equiperdum has emerged at least once in Eastern Africa and T. evansi at two independent occasions in Western Africa.[18]
Selected species
Species of Trypanosoma include the following:
- T. ambystomae. in amphibians
- T. antiquus, extinct (Fossil in Miocene amber)
- T. avium, which infects birds and blackflies
- T. bennetti, which infects birds and biting midges
- elasmobranch
- naganain cattle
- T. cruzi, which causes Chagas disease in humans
- Trypanosoma culicavium, which infects birds and mosquitoes
- naganain ruminant livestock, horses and a wide range of wildlife
- Tabanidae,
- , it can be spread through coitus.
- T. evansi, which causes one form of the disease surra in certain animals including camels[19] (a single case report of human infection in 2005 in India[20] was successfully treated with suramin[21])
- T. everetti, in birds
- T. hosei, in amphibians
- T. irwini, in koalas
- T. lewisi, in rats
- T. melophagium, in sheep, transmitted via Melophagus ovinus
- T. parroti, in amphibians
- Perca fluviatilis
- T. phedinae
- T. rangeli, believed to be nonpathogenic to humans
- T. rotatorium, in amphibians
- T. rugosae, in amphibians
- T. sergenti, in amphibians
- naganain pigs. Its main reservoirs are warthogs and bush pigs
- T. sinipercae, in fishes
- T. suis, which causes a different form of surra
- T. theileri, a large trypanosome infecting ruminants and transmitted by a variety of vectors including tabanids and mosquitoes
- T. thomasbancrofti, an avian trypanosome with culicine mosquito vector
- T. triglae, in marine teleosts
- T. tungarae, in frogs[22]
- nagana, mainly in West Africa, although it has spread to South America[23]
Hosts, life cycle and morphologies
Two different types of trypanosomes exist, and their life cycles are different, the salivarian species and the stercorarian species.[citation needed]
Stercorarian trypanosomes infect insects, most often the triatomid kissing bug, by developing in the posterior gut followed by release into the feces and subsequent depositing on the skin of the vertebrate host. The organism then penetrates and can disseminate throughout the body. Insects become infected when taking a blood meal.[citation needed]
Salivarian trypanosomes develop in the anterior gut of insects, most importantly the Tsetse fly, and infective organisms are inoculated into the host by the insect bite before it feeds.[citation needed]
As trypanosomes progress through their life cycle they undergo a series of morphological changes as is typical of
Meiosis
Evidence has been obtained for meiosis in T. cruzi, and for genetic exchange.[24] T. brucei is able to undergo meiosis within the salivary glands of its tsetse fly host, and meiosis is considered to be an intrinsic part of the T. brucei developmental cycle.[25][26] An adaptive benefit of meiosis for T. crucei and T. brucei may be the recombinational repair of DNA damages that are acquired in the hostile environment of their respective hosts.[27]
References
- ^ "WHO - The parasite". WHO. Archived from the original on September 29, 2016. Retrieved 8 March 2019.
- PMID 15542100.
- ^ "Taxonomy of African Trypanosoma species". msu.edu. Retrieved 2019-03-28.
- ^ Leadbeater, B.S.C & McCready, S.M.M. (2000). The Flagellates. Unity, diversity and evolution. Ed.: Barry S. C. Leadbeater and J. C. Green Taylor and Francis, London, p. 12.
- ^ Valentin, G. 1841. Ueber ein Entozoon im Blute von Salmo fario. Müller's Archiv, p. 435.
- ^ Gruby, D. 1843. Recherches et observations sur une nouvelle espéce d'haematozoaire, Trypanosoma sanguinis. Comptes Rendus de l'Académie des Sciences, 17: 1134–1136, [1].
- PMID 16562450.
- ^ "salivarian". Retrieved 8 March 2019 – via The Free Dictionary.
- ^
- ^ Prevention, CDC-Centers for Disease Control and (2 May 2017). "CDC - Chagas Disease - General Information". www.cdc.gov. Retrieved 8 March 2019.
- ^ "Stercoraria". Retrieved 8 March 2019 – via The Free Dictionary.
- . Retrieved 4 October 2021.
- ^ Brun R, Hecker H, Lun ZR (1998) Trypanosoma evansi and T. equiperdum: distribution, biology, treatment and phylogenetic relationship (a review). Vet Parasitol 79(2):95-107
- ^ Carnes J, Anupama A, Balmer O, Jackson A, Lewis M, Brown R, Cestari I, Desquesnes M, Gendrin C, Hertz-Fowler C, Imamura H, Ivens A, Kořený L, Lai DH, MacLeod A, McDermott SM, Merritt C, Monnerat S, Moon W, Myler P, Phan I, Ramasamy G, Sivam D, Lun ZR, Lukeš J, Stuart K, Schnaufer A (2015) Genome and phylogenetic analyses of Trypanosoma evansi reveal extensive similarity to T. brucei and multiple independent origins for dyskinetoplasty. PLoS Negl Trop Dis 9(1):e3404. doi: 10.1371/journal.pntd.0003404
- ^ Cuypers B, Van den Broeck F, Van Reet N, Meehan CJ, Cauchard J, Wilkes JM, Claes F, Goddeeris B, Birhanu H, Dujardin JC, Laukens K, Büscher P, Deborggraeve S (2017) Genome-wide SNP analysis reveals distinct origins of Trypanosoma evansi and Trypanosoma equiperdum. Genome Biol Evol doi: 10.1093/gbe/evx102
- S2CID 13783061. Article Number 21. p. 2
- PMID 15771199.
- PMID 16455122.
- PMID 26977404
- PMID 21569364.
- PMID 26188331.
- PMID 21321215.
- S2CID 9594154.
- ^ Bernstein H, Bernstein C, Michod RE (2018). Sex in microbial pathogens. Infection, Genetics and Evolution volume 57, pages 8-25. https://doi.org/10.1016/j.meegid.2017.10.024
External links
- Trypanosoma reviewed and published by Wikivet, accessed 08/10/2011.
- Trykipedia, Trypanosomatid specific ontologies
- Tree of Life: Trypanosoma