Rickettsia parkeri

Rickettsia parkeri is an obligate intracellular bacterial pathogen that primarily targets vascular endothelial cells, but also infects macrophages and epithelial cells. Infection of the endothelium leads to leakage of vascular fluid, causing a characteristic eschar and rash, along with fever, headache, and myalgia. Tick vectors transmit this bacterium from infected mammals (e.g., rodents) to humans. The disease caused by R. parkeri (Rickettsia parkeri rickettsiosis) is generally milder than those caused by other spotted fever group (SFG) Rickettsia spp., such as Rickettsia rickettsii (Rocky Mountain spotted fever) and Rickettsia conorii (Mediterranean spotted fever). Consequently, R. parkeri is tractable in a biosafety level 2 (BL2) laboratory setting, making it an accessible model for pathogenic SFG Rickettsia.