Trypanosoma(Megatrypanum)lainsonin. sp. fromMesomys hispidus(Rodentia: Echimyidae) in Brazil: trypomastigotes described from experimentally infected laboratory mice

Abstract

We report the detection, isolation and description of Trypanosoma (Megatrypanum) lainsoni n. sp. from a caviomorph rodent, Mesomys hispidus (Rodentia: Echimyidae), obtained in the Rio Negro region of the state of Amazonas, in northern Brazil. Laboratory-bred white mice (Mus musculus) and rats (Rattus rattus) were inoculated with large numbers of culture forms by intraperitoneal route, and trypomastigotes appeared in their blood 3–8 days post-inoculation. One single epimastigote was also found in Mus musculus. Similar attempts to infect Rattus norvegicus, hamsters (Mesocricetus auratus), the opossum Didelphis marsupialis, the anteater Tamandua tetradactyla and triatomine bugs were unsuccessful, following six months of observations and microscopic examinations of blood films and blood cultures. As we have found no previous record of a Trypanosoma (Megatrypanum) species naturally infecting a member of the family Echimyidae, or any other caviomorph rodent, we conclude that this is the first time such an infection has been reported. The new species is unusual in the subgenus for its infectivity to laboratory mice.

Uncovering Trypanosoma spp. diversity of wild mammals by the use of DNA from blood clots

“…T. lainsoni was only described twice and in these two times, only in Amazonian rodents (Naiff and Barrett, 2013; Ortiz et al, 2018). Here, using a more sensitive methodology, we enlarged the knowledge of hosts taxa and geographical distribution of this trypanosome since we found T. lainsoni infecting marsupials and bats in Atlantic Forest and Cerrado.…”

A Novel Genotype and First Record of Trypanosoma lainsoni in Argentina

“…The parasites were isolated from mammalian hosts in the Copo National Park, Santiago del Estero province, in the Argentine Chaco region. They were identified as Trypanosoma lainsoni , a species previously described from the blood of a rodent (genus Mesomys ) in Brazil [ 13 ] and later included within the LSRM clade [ 10 ]. This report represents the first isolate of this species recorded for Argentina.…”

“…Based on this size, the Amazonian isolate was considered as part of the subgenus Megatrypanum [ 10 , 12 , 22 ]. Consequently, T. lainsoni was granted the status of a new species because there was no record of Megatrypanum isolates from a rodent caviomorph [ 13 ]. Afterwards, other studies reaffirmed the status of new species according to molecular data [ 10 ].…”

“…After first descriptions and based on phylogenetic analyses, this group was expanded to also include parasites from rodents and marsupials, i.e., T. freitasi and T. lainsoni. Consequently, the clade was renamed to lizard and snake/rodent and marsupial (LSRM) [ 7 , 10 , 11 , 12 , 13 ]. Particularly, T. lainsoni was represented by a single isolate from a caviomorph rodent of the genus Mesomys in the northern state of Amazona, Brazil.…”

“…South America has a great number of trypanosome species, parasitizing a wide diversity of hosts. However, most of the reports on isolations are registered in Brazil [ 7 , 10 , 11 , 12 , 13 , 14 , 15 ], while in Argentina, just three species were reported: T. cruzi (the agent of Chagas disease), T. evansi , and T. vivax [ 16 , 17 , 18 , 19 ].…”