Metabolic Activity of Purified Suspensions of Rickettsia rickettsi

THE independent metabolic activities of some of the obligate intracellular bacteria, such as rickettsiae and chlamydiae1, have been extensively investigated2. Such work has rarely included Rickettsia rickettsi, the agent of Rocky Mountain spotted fever, because of the difficulty of obtaining sufficient material of adequate purity and stability. The only data on respiration of R. rickettsi are those given in a preliminary report by Price3, who carried out his experiments with the collection from several thousand infected yolk sacs and tested the micro-organisms immediately after the final step of purification.