Broth microdilution susceptibility testing of Francisella tularensis: quality control limits for nine antimicrobial agents and three standard quality control strains.

For broth microdilution susceptibility tests of Francisella tularensis, Mueller-Hinton broth with 2% Isovitalex is recommended. Using that medium, we studied three standard control strains tested with nine antimicrobial agents potentially efficacious for treating tularemia. An eight-laboratory collaborative study generated the data needed to propose appropriate MIC control limits.