Bactericidal activities of antibiotics against intracellular Francisella tularensis.

MICs of many antibiotics for Francisella tularensis are low in axenic medium, whereas only aminoglycosides, tetracyclines, and fluoroquinolones are useful in treating tularemic patients. In an in vitro cell system, only these antibiotics, rifampin, and telithromycin were bactericidal against intracellular F. tularensis. These results correlate better with clinical data than MIC data do.