Establishment of cell cultures persistently infected with spotted fever group rickettsiae.

A cell line was established from the tunica vaginalis of meadow voles, Microtus pennsylvanicus, which could be persistently infected with the spotted fever group rickettsiae, Rickettsia rickettsii, R. rhipicephali, and R. slovaca. As determined by light and electron microscopy, all cells in the cultures became infected and remained so even after 20 serial passages over a period of months. The rickettsiae-infected vole cell line is an excellent experimental model to study the noncytolytic host-cell interactions required for persistence of spotted fever group rickettsiae in nature.