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Nora M.M.,Laboratorio Of Parasitologia Experimental Lapex | Elio M.B.,Laboratorio Of Parasitologia Experimental Lapex | Alarcon M.,Laboratorio Of Parasitologia Experimental Lapex | Lugo De Yarbuh A.,Laboratorio Of Parasitologia Experimental Lapex | And 2 more authors.
Kasmera | Year: 2012

The resistance to reinfection by Trypanosome cruzi in chagasic rat offspring was evaluated. Thirty male offspring (B) from infected mothers and 30 offspring B from healthy mothers were used, divided into groups of 10 offspring each (I, II, III) and (IV, V, VI). The groups (I, IV) and (II, V) were inoculated and reinoculated by intradermal route with 5 × 104metacyclictrypomastigotes of homologous (pL) and heterologous (Y) strains of T. cruzi, from laboratory infected Rhodnius prolixus, at one-month intervals. The control groups (III, VI) received saline injections. The parasitological and serological testing performed on both groups of infected offspring at 10, 20 and 30 days post-reinoculation (pr) showed significantly higher parasitemia levels in offspring from healthy mothers during the acute phase of the primary infection, the absence of bloodstream trypomastigotes after the 1st and 2nd reinoculation, and a significant increase in anti-T. cruzi antibody levels after initial inoculation and reinoculations. The histopathological and immunohistochemical analysis of heart and skeletal muscle sections from the offspring sacrificed at 45, 75 and 105 days pi, revealed the gradual establishment of myocarditis and acute myositis of variable intensity accompanied by few nests of amastigotes, a worsening of the pathologic picture produced by the initial inoculation, and the presence of abundant antigenic deposits that intensified with the reinoculations. In conclusion, the resistance of offspring born from chm to homologous and heterologous reinfection by T. cruzi strains, is produced, first, by vertical transmission of the parasites and/or humoral antibodies from infected mothers to their progeny, and second, by a sensibilization process in the host from continuous antigenic downloads produced when the inoculated parasites are destroyed.

Cazorla D.,Francisco de Miranda National Experimental University | Sanchez M.,Laboratorio Of Parasitologia Experimental Lapex | Sanchez Y.,Laboratorio Of Parasitologia Experimental Lapex | Oraa L.,Laboratorio Of Parasitologia Experimental Lapex | And 6 more authors.
Revista Peruana de Biologia | Year: 2014

The moth fly (Diptera: Psychodidae) of the Bruchomyiinae subfamily Nemopalpus phoenimimos Quate & Alexander, 2000 is recorded for the first time in Venezuela. Two specimens were collected at 2200 m of altitude in Escagüey (8°42″31.19″N; 70°59″41.25″W), Mérida state, from Venezuelan Andes region. This record represents the second Nemopalpus Macquart, 1838 species reported from this country. © Los autores.

Alarcon M.,Laboratorio Of Parasitologia Experimental Lapex | Moreno E.,Laboratorio Of Parasitologia Experimental Lapex | Colasante C.,Conducta | De Yarbuh A.L.,Laboratorio Of Parasitologia Experimental Lapex | And 2 more authors.
Boletin de Malariologia y Salud Ambiental | Year: 2011

We report the presence of evolving forms of Trypanosoma cruzi in the seminal plasma (SP) of NMRI mice subcutaneously inoculated with 2x104 metacyclic trypomastigotes obtained from P6 strain Rhodnius prolixus. When taking blood samples at 15 days post-infection, the mouse spontaneously ejaculated and the direct SP exam revealed the presence of active epimastigotes of T. cruzi mixed with spermatozoids. SP preparations stained with Giemsa showed free and dividing epimastigotes, extracellular trypomastigotes and amastigotes, as well as, within phagocytic cells. The results showed the presence of T. cruzi at the different stages of its life cycle in the mouse PS, observing similar morphogenesis in the PS to the one known in the insect vector. The parasitism found in the SP of this mouse with acute infection, provides important epidemiological information about the T. cruzi pathway of sexual transmission, mainly among the population of wild reservoirs found in endemic and non-endemic areas for Chagas'disease.

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