Susceptibility of laboratory animals to infection by spotted fever group rickettsiae.

An attempt was made to find a suitable animal model for studies of spotted fever group rickettsiae. Inbred and outbred mice, the guinea pig, ferret, gerbil, hamster, wild rabbit, cotton rat, sheep, and miniature swine were tested. Of these, only certain strains of the mouse [Mai:(S) and BALB/cJ] and the guinea pig [Hla:(HA)] exhibited, overtly, the desired characteristics of disease. Other laboratory animals (such as sheep or rabbits) can be used for the production of antiserum against the spotted fever group of rickettsiae; however, these rickettsiae apparently have little or no effect on several other animal species. The lack of overt disease might explain the role of these animals or related genera as reservoirs for the tick-borne spotted fever rickettsiae.