Trypanosoma (Herpetosoma) rangeli Tejera, 1920: intracellular amastigote stages of reproduction in white mice

Abstract

SUMMARYThe method, site, and stage of multiplication of Trypanosoma (Herpetosoma) rangeli Tejera, 1920 has not hitherto been known. "We have now observed many intracellular nests or pseudocysts, containing amastigotes and trypomastigotes of this parasite in the heart, liver, and spleen of suckling (5.0 g) male white mice (NMRI strain) inoculated i.p. with 9 x 10 4 metatrypomastigotes/g body weight from a 12-day-old culture of the "Dog-82" strain of T. rangeli. At the peak of parasitemia (1.9 x 10 6 trypomastigotes/ml blood, 3 days post-inoculation) va rious tissues were taken for sectioning and staining. The heart was most inten sely parasitized.The amastigotes were rounded or ellipsoidal, with a rounded nucleus and the kinetoplast in the form of a straight or curved bar; the average maximum diameter of 50 measured amastigotes was 4.2 p. Binary fission was seen in the nucleus and kinetoplast of some amastigotes; no blood trypomasti gotes were seen in division. The above characteristics, as well as the location of the pseudocysts in the tissues, are similar to T. cruzi. Comparison of these re sults with those reported for other Herpetosoma suggest study of the taxonomic position of T. rangeli.

Characterization of a Trypanosoma rangeli Strain of Colombian Origin

“…Moreover, the viability of T. rangeli intracellular parasites has been suggested to be able to survive intracellularly over extended periods (Osorio et al 1995). Few inflammatory infiltrates were found in the histopathological sections, suggesting as Osorio et al (1995) that T. rangeli infection did not elicit a strong host response, in agreement with the low antigenicity of natural infections by T. rangeli (D'Alessandro-Bacigalupo & Saravia 1992) and the low and brief immune responses observed in experimentally infected animals (Añez et al 1985, Urdaneta-Morales & Tejero 1986.…”

“…In spite of T. rangeli intracellular multiplication could remain in the speculative field, some authors have been able to find parasite tissular forms in vertebrate hosts (Urdaneta & Tejero 1986). Moreover, the viability of T. rangeli intracellular parasites has been suggested to be able to survive intracellularly over extended periods (Osorio et al 1995).…”

“…Study of parasitism of this flagellate in mammalian hosts has been hampered by the difficulty of obtaining bloodstream forms in the laboratory animals with very low parasitemias and short duration in experimental animals (Urdaneta-Morales & Tejero 1986). Another important fact is the scarcity of studies about the influence of several factors in the infection such as parasite strain, inoculum dose, hosts age and sex, and immune response related to the host.…”

Serological Diagnosis of Trypanosoma rangeli Infected Patients. A Comparison of Different Methods and its Implications for the Diagnosis of Chagas' Disease

“…While there appears to be no pathogenesis of infection in humans, experimental infections have been reported with parasites present in intracellular locations [42][43][44]. The parasite exists in the same areas as the pathogenic T. cruzi, and shares the same insect vectors.…”

Genes de cisteíno proteases (Catepsina L-like) de Trypanosoma rangeli: polimorfismo, relações filogenéticas e alvos para diagnóstico e genotipagem.

“…Os únicos casos de infecção humana no Brasil foram descritos nos estados do Amazonas e Bahía DE SOUSA et al, 2008 (HOARE, 1972;SOUSA e DAWSON, 1976;MILES et al, 1983;STEINDEL et al, 1991;CUBA-CUBA, 1998;MAIA DA SILVA et al, 2004a, b, 2007 TEJERO, 1985SCORZA et al, 1986;CUBA-CUBA, 1998; D'ALESSANDRO e GORE-SARAVIA, 1999;). Embora formas tripomastigotas do parasita tenham sido observadas no sangue de humanos e de animais domésticos e silvestres, o ciclo de vida no hospedeiro vertebrado não foi totalmente determinado e os dados são escassos e controvertidos (AÑEZ et al, 1985;STEINDEL, 1993;OSORIO et al, 1995;EGER-MANGRICH et al, 2001).…”