Homogeneity of Trypanosoma evansi isolates from domestic and sylvatic mammals from the Pantanal of Mato Grosso

'Mal de Cadeiras' is a disease which causes great mortality in horses in the Pantanal Matogrossense region, Brazil. The agent of this disease is Trypanosoma evansi, a kinetoplastid flagellate which belongs to the Trypanosomatidae family, classified into the Salivarian section. Transmission occurs mechanically by haematophagous Diptera, mainly by Stomoxys sp. and Tabanus sp. and vampire bats. Outbreaks of Mal de Cadeiras in horses result in economic losses, thus limiting their use in cattle raising. Ten isolates of T. evansi recently derived from coati (Nasua nasua, Carnivora, Procyonidae), horses and dogs were compared, using schizodeme analyses from DNA digested by the restriction enzyme Hin fl. The results showed similar electrophoretic profiles for all isolates from wherever the host came. Homogeneity of isolates from domestic and sylvatic animals suggested two hypotheses: (1) the parasites circulated in only one transmission cycle;, and (2) independent cycles were not established in sufficient time to modify the molecular profiles of the isolates.