what is the rickettsia rickettsii vaccine
Student presentation on. Rickettsia rickettsii, Causitive Agent of Rocky Mountain Spotted Fever. The Bacteria. Rickettsia rickettsii is the small, aerobic gram-negative bacterium that is the cause Rocky Mountain spotted fever in humans (and other vertebrates).They are obligate, intracellular bacteria that range in size form 0.2x0.5 Âµm to 0.3x2.0Âµm.tudent presentation on. Rickettsia rickettsii, Causitive Agent of Rocky Mountain Spotted Fever. The Bacteria. Rickettsia rickettsii is the small, aerobic gram-negative bacterium that is the cause Rocky Mountain spotted fever in humans (and other vertebrates).