Primary isolation of spotted fever group rickettsiae from Amblyomma cooperi collected from Hydrochaeris hydrochaeris in Brazil oleh Elba Regina Sampaio de Lemos, Heloísa Helena Barbosa Melles, Sílvia Colombo, Raimundo Diogo Machado, José Rodrigues Coura, Maria Angélica Arpon Guimarães, Selênio R Sanseverino, Aline Moura