This paper reports the first isolation of a spotted fever
group rickettsia from an Amblyomma cooperi ixodid
collected from a capybara (Hydrochaeris hydrochaeris) in
an endemic area of spotted fever in the County of Pedreira, State
of S o Paulo, Brazil. Isolation was performed in Vero cell
culture and submitted to immunofluorescence, using antibody from
Rickettsia rickettsii-positive human serum.