Diagnóstico y caracterización molecular de infecciones naturales por Trypanosoma spp. en bovinos de la Orinoquía Colombiana

Because of the limitations of direct methods for the diagnosis of trypanosomes in small quantities, molecular methods which allow identification of the species with a small amount of parasite DNA were analyzed. A study was conducted at the Carimagua Experimental Station, located in the flat high plains of Orinoco Colombia. From 500 'Sanmartinero' and 'Zebú' breeding cattle, native to the area, 70 clinically healthy animals were randomly selected, to establish the presence of Trypanosoma spp. and to perform differential diagnosis between species. Blood samples were taken and linfocites were separated by the Buffy Coat technique. Seminested PCR was performed on the 18S rDNA region. RFLP was run on the obtained products and a comparison with international standards was made. Five samples were positive for Trypanosoma spp. by PCR. One of them corresponded to T. vivax and four to T. theileri. The results obtained estimate a prevalence of 7.14% in apparently healthy animals, otherwise not detected by traditional direct tests currently in use. This poses a potential problem for cattle in the area, given the chance of developing clinical symptoms of the disease and the likelihood of transmission to susceptible animals. Having methods to detect presence of the species Trypanosoma spp., also permits better management and understanding of the field problem. The methods described are the first molecular approach to study Trypanosoma spp. in cattle in the Colombian Orinoco region and highlight the importance of diagnosis of the disease. Debido a las limitaciones que tienen los métodos directos para el diagnóstico de tripanosomas en bajas cantidades, los métodos moleculares permiten la identificación de la especie con una pequeña cantidad del ADN del parásito. Se realizó un estudio en la Estación Experimental Carimagua ubicada en la altillanura plana de la Orinoquía Colombiana, con una población de 500 bovinos de cría de las razas Cebú y Sanmartinero nacidos en la zona, se seleccionaron de manera aleatoria 70 animales clínicamente sanos, con el fin de establecer la presencia de Trypanosoma spp. y realizar un diagnóstico diferencial entre especies. Se tomaron muestras de sangre en las cuales, se separaron glóbulos blancos mediante la técnica de Buffy Coat, y se realizó PCR semi-anidado sobre la región 18S del rDNA. Sobre los productos obtenidos se realizó el RFLPS y su comparación con estándares internacionales. Cinco muestras por PCR fueron positivas a Trypanosoma sp