Pesquisa de anticorpos contra Leptospira spp. em animais silvestres e em estado feral da região de Nhecolândia, Mato Grosso do Sul, Brasil: utilização da técnica de imuno-histoquímica para detecção do agente

Three hundred and fifteen serum samples of several animal species living in wild or in feral state in the area of Nhecolândia, Corumba, MS, Brazil, were examined by the microscopic agglutination test. Of these samples, 67 were of feral bovine (Bos taurus indicus), 39 of feral pigs (Sus scrofa), 39 of buffaloes (Bubalus bubalis), nine of coatis (Nasua nasua), 41 of pampas deer (Ozotoceros bezoarticus), 10 of brocket deer (Mazama americana) and 110 of feral sheep (Ovis aries). In 12 dead animals (six feral pigs, four pampas deer and two feral sheep), isolation attempts and Leptospira identification through the immunohistochemistry were accomplished. Sixty-four (20.3%) of the samples reacted to at least one serovar of pathogenic Leptospira; 41.0% of the buffaloes, 40.3% of the feral bovine, 17.9% of the feral pigs, 9% of the feral sheep, and 9.7% of the pampas deer serum samples were reactors. All the serum samples of brocket deer and of coatis were not reactors. The most frequent serovars for the studied animal species were: pomona for buffaloes and feral sheep; icterohaemorrhagiae for feral sheep, pampas deer and feral pigs; and copenhageni for pampas deer and feral pigs. The attempts of Leptospira isolation resulted negative, and the immunohistochemistry analysis revealed Leptospira in the liver of one feral pig. Microscopic examination of the kidney revealed vascular congestion, hemorrhage and infiltration of mononuclear inflammatory cells in the interstice.