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 th e Pantanal Matogrossense region, Brazil. The agent of this disease is Trypa nosoma evansi, a kinetoplastid flagellate which belongs to the Trypanosomat idae family, classified into the Salivarian section. Transmission occurs me chanically by haematophagous Diptera, mainly by Stomoxys sp. and Tabanus sp . and vampire bats. Outbreaks of Mal de Cadeiras in horses result in econom ic losses, thus limiting their use in cattle raising. Ten isolates of T: ev ansi recently derived from coati (Nasua nasua, Carnivora, Procyonidae), hor ses and dogs were compared, using schizodeme analyses from UNA digested by the restriction enzyme Hin fl. The results showed similar electrophoretic p rofiles for all isolates from wherever the host came. Homogeneity of isolat es from domestic and sylvatic animals suggested two hypotheses: (1) the par asites circulated in only one transmission cycle;, and (2) independent cycl es were not established in sufficient time to modify the molecular profiles of the isolates.