Bacterium
Rickettsia rickettsii
Obligate intracellular tick-borne bacterium
rih-KET-see-uh rih-KET-see-eye
High-yield clue
Obligate intracellular + tick vector + vasculitis/rash vocabulary.
Overview
An obligate intracellular bacterium used to teach tick-borne spotted fever vocabulary and endothelial-cell tropism concepts.
Classification
- Obligate intracellular bacterium
- Small Gram-negative concept
- Vector-borne
Lab & identification clues
- Serology vocabulary
- PCR term recognition
- Intracellular growth concept
Associations
- Rocky Mountain spotted fever vocabulary
- Endothelial injury concept
- Tick exposure framing
Commonly confused with
- Borrelia burgdorferi
- Ehrlichia/Anaplasma vocabulary
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.