Identification of Endotrypanum Species from a Sloth, a Squirrel, and Lutzomyia Sandflies in Ecuador by PCR Amplification and Sequencing of the Mini-Exon Gene

The genus Endotrypanum is a trypanosomatid parasite transmitted by sandfly vectors into sloths in Central America and South America. As of now, only two species of Endotrypanum have been described. Endotrypanum parasites from in vitro cultures of infected sloth blood and from Lutzomyia sandflies has indistinguishable promastigote stages compared to Leishmania promastigotes (Katakura et al. 2003). Sloths are also a reservoir host for several species of Leishmania, including Leishmania equatorensis, so classifying Endotrypanum and Leishmania is important for further studies on sandfly vectors and reservoir hosts.

Species of trypanosomatid parasites were re-examined by sequencing DNA polymerase, RNA polymerase, and by isoenzyme electrophoresis analysis. The results suggested several Leishmania species were more closely related to Endotrypanum than to other species of Leishmania. A PCR method was created for diagnosis of visceral and cutaneous leishmaniasis, although this new PCR method is used for detecting the Leishmania mini-exon gene. The mini-exon gene is present in all trypanosomatid parasites, but is absent from sandfly vectors and mammalian hosts. (Katakura et al. 2003).

The results of this study showed a very close similarity to Endotrypanum genus and Leishmania equatorensis and the sequence data of the mini exon gene showed that Leishmania equatorensis is most likely a parasite within Endotrypanum genus. This will be important in future classifying of Endotrypanum and Leishmania, including their sandfly vectors and reservoir hosts.

This article ties in with the article “Description of Leishmania equatorensis Sp. N. (Kinetoplastida: Trypanosomatidae), A New Parasite Infecting Arboreal Mammals in Ecuador” by Gabriel et al. (1992) because both papers study relationships between Leishmania equatorensis and other parasites. Leishmania equatorensis is an understudied parasite that studies have shown has similarities not only to other Leishmania strands, but also to the Endotrypanum genus.

Citation

K. Katakura, T. Mimori, M. Furuya, H. Uezato, S. Nonaka, M. Okamoto, E. Gomez, Y. Hashiguchi, 2003, Identification of Endotrypanum Species from a Sloth, a Squirrel, and Lutzomyia Sandflies in Ecuador by PCR Amplification and Sequencing of the Mini-Exon Gene, J. Vet. Med. Sci. 65(5): 649-653

-Kaitlin Smith