Rickettsia

Categorization
Cell Wall: Gram Negative Shape: Rod
Life Cyle: Obligate Intracellular Parasite
Overview
  • Rickettsia are a genus of obligate intracellular gram negative bacteria whose transmission, pathogenesis, and clinical consequences are highly similar. Species of Coxiella and Ehrlichia are included here due to their similarity with Rickettsial species. As obligate intracellular parasites, Rickettsial species can only replicate in host cells because they cannot produce their own ATP and must derive this energy source from the host cells which they infect. Rickettsial species replicate inside the cells cytoplasm (In contrast, Chlamydial species replicate inside intracellular endosomes).
Pathogenesis
  • In general, Rickettsial species infect endothelial cells and so tend to produce vasculitis.
Clinical Consequences
  • Most rickettisal species produce a constellation of high fever, headaches, and skin rash.
Transmission
  • Most Rickettsial species are transmitted by arthropod vectors during blood meals.
Treatment
  • Treatment for all Rickettsial diseases is doxycycline or chloramphenicol.
Member Organisms