Rickettsia australis

[ô-strālĭs]
n.
  1. A bacterium causing a spotted fever that elicits the production of an antibody that is different from the one that reacts with other rickettsial species.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.