Characterization of Endotrypanum (Kinetoplastida: Trypanosomatidae), a Unique Parasite Infecting the Neotropical Tree Sloths (Edentata)

Abstract

Key words: Endotrypanum -Protozoa -Kinetoplastida -Trypanosomatidae -molecular taxonomy -enzyme activities -monoclonal antibodies -enzyme electrophoresis -DNA analyses -mammalian reservoirssandflies vectorsBiological characteristics of Endotrypanum spp. -Parasitic protozoa of the genus Endotrypanum are unique among the Kinetoplastida in that they infect erythrocytes of their mammalian host. Infection with Endotrypanum appears to be restricted to edentates, principally of forest-dwelling two-toed sloths of the genus Choloepus, but rarer infections with these flagellates seems to occur in three-toed sloths (genus Bradypus) (Fig. 1). As shown in Fig. 2, inside the erythocyte the Endotrypanum assumes an epimastigote or trypomastigote form, while in the sandfly or during in vitro culture the parasite assumes promastigote morphology (Shaw 1992). However, the complete life cycle of Endotrypanum spp. has not been reproduced in experimental studies. Other developmental stages of the parasite may occur within the mammalian host (Deane 1961).In nature, Endotrypanum parasites are probably transmitted by the bite of infected phlebotomine sandflies (Diptera: Psychodidae). Arias et al. (Rogers et al. 1988). Further evidence for the development of Endotrypanum in phlebotomines was obtained by feeding several laboratory-reared sandfly species on infected sloths (Shaw 1964, 1969, 1981, Christensen & Herrer 1977, 1979. In these studies, infections developing within the insect gut (Shaw 1964(Shaw , 1969 were similar to those found in wild caught sandflies (Johnson et al. 1963, Arias et al. 1985. Moreover, we have reported (Franco et al. 1997b) the developmental biology of Brazilian strains of Endotrypanum for three sandfly species. Development of Endotrypanum varied for each parasitehost species association. After feeding on culture forms of E. schaudinni, significantly more Lu. shannoni (100%, 9/9) became infected than did Lu. longipalpis (62.3%, 33/53) or Phlebotomus papatasi (27.3%, 15/55). The greatest number of infections were in the midgut and hindgut from 6 to 16 days after feeding, but flagellates also were present in the Malpighian tubules. Moreover, distinct development patterns in the sandfly gut were obtained when the Callejon Lu. longipalpis colony was fed on cultures of other Endotrypanum strains.

Flebotomíneos (Díptera: Psychodidae) de uma Floresta Primária de Terra Firme da Estação Experimental de Silvicultura Tropical, Estado do Amazonas, Brasil

“…Estudos usando técnicas moleculares (KDNA) para a detecção de parasitos em flebótomos também demonstraram infecção por Endotrypanum em L. shannoni, L. umbratilis e L. anduzei (Franco & Grimaldi, 1999).…”

First human cases of Leishmania (Viannia) naiffi infection in Ecuador and identification of its suspected vector species

“…yuilli yuilli (3.9%) and two of 54 Lu. tortura (3.7%) ( (Shaw, 1964;Franco and Grimaldi, 1999 1). Leishmania (V.) naiffi was originally described as a parasite of armadillos in the Amazonian area of Brazil .…”

“…is not pathogenic to humans (Shaw, 1964;Franco and Grimaldi, 1999;Katakura et al, 2003). In Ecuador, Endotrypanum species have been isolated from Lu.…”

Revised classification of the subfamily Leishmaniinae (Trypanosomatidae)

“…Firstly and most significantly, these strains were never shown to infect erythrocytes in experimental infections. Secondly, they are morphologically distinct from the forms observed in sloth's blood (Shaw 1964, Franco andGrimaldi 1999).…”