Rickettsiae of the spotted fever isolated from Dermacentor marginatus ticks in South Germany.

Rickettsiae of the spotted fever group were detected by haemocyte test in 8 (12%) of 51 partially engorged Dermacentor marginatus females collected in March/April 1975 in South Germany. Four strains of rickettsiae were isolated from ticks positive in haemocyte test. It was concluded with isolated strain BRD-1 and homologous immune guinea pig, hamster and mouse sera in CF cross reactions with antigens and immune sera against other members of the SF group, that the newly isolated strains are similar, almost undistinguishable from Rickettsia slovaca.