Article
Detection and PCR Characterization of Parasites Causing Trypanosomiasis in Water Buffaloes Herds in Venezuela
Registro en:
1364-8594, 0003-4983
Autor
Garcia, Herakles
Garcia, M.E
Perez, H
Mendoza-León, Alexis
Institución
Resumen
The usefulness of PCR-based assays for detecting trypanosomiasis in water buffaloes and other livestock was
explored, under field conditions, in Venezuela. The sensitivity and specificity of the assays, which were based on
established primer pairs (21-mer/22-mer and ILO1264/ILO1265), were evaluated, partly by comparison with the
results of parasitological tests (stained bloodsmears and microhaematocrit centrifugation) and immunological
assays (IFAT) run in parallel. The optimised PCR-based assays showed a sensitivity of 10 pg DNA. The use of the
21-mer/22-mer primer pair gave a test that was specific for species in the subgenus Trypanozoon (including
Trypanosoma evansi), whereas use of ILO1264/ILO1265 produced a test that was specific for T. vivax. The results
of a hybridization assay using T. evansi-DNA and T. vivax-DNA probes indicated no cross-hybridization between
the T. evansi and T. vivax PCR products.
The results of the bloodsmear examinations, microhaematocrit centrifugations (MHC) and IFAT indicated that
23 (6.7%), 39 (11.4%) and 135 (39.5%) of the 342 blood samples investigated (including 316 from water
buffaloes) contained trypanosomes, respectively. The results of the PCR-based assays indicated that 68 (19.9%) of
the same blood samples contained T. vivax (or at least T. vivax DNA), and that none contained T. evansi or any
other member of the subgenus Trypanozoon. For the detection of trypanosomes, the assay therefore appeared
almost twice as sensitive as the MHC. These results are the first on the molecular characterization of the
trypanosomes infecting water buffaloes in Venezuela This work was financially
supported by grants S1-2001000988
and S1-2001000705 from the Fondo
Nacional de Ciencia, Tecnologı´a e Innovacio´n
(Ministerio de Ciencia y Tecnologı´a) and grant
PI:11-10-4832-01 from the Consejo de Desarrollo
Cientı´fico y Humanı´stico (Universidad Central de Venezuela). The authors are very
grateful to Professors J. Rojas, T. Diaz and T.
Sanchez (all of the Universidad Central de
Venezuela) for improving their English. They
particularly thank Professor H. Zerpa, for his
critical reading of the manuscript. Many of
the DNA samples used to develop the PCRbased
assays were kindly donated by Drs F.
Bringaud and A. M. Davila