Multiplication of Rickettsia prowazekii in cotton rat macrophage cultures.

The susceptibility of cotton rat macrophages to Rickettsia (R.) prowazekii, the percentage of the affected cells, and the intensity of damage to individual cells by rickettsiae were found to be much higher than those in guinea pig macrophages infected under similar conditions. At the same time, cotton rat macrophages proved to be more resistant to the effect of rickettsiae than guinea pig macrophages. Some common features of infection in cell culture and in animals have been observed. It is suggested that the outcome of interaction of rickettsiae with macrophages of one or another animal species may be important in generating acute or persistent infection.