scope:

CLSI document M24-A2 contains protocols for the susceptibility testing of three major categories of mycobacterial species (Mycobacterium tuberculosis complex [MTBC]; the slowly growing nontuberculous mycobacteria [NTM]; and the rapidly growing mycobacteria) and recommendations for susceptibility testing of Nocardia spp. and miscellaneous aerobic actinomycetes. This document also provides guidance on the selection of primary and, for some organisms, secondary agents for testing and reporting; instructions for performing the standard agar proportion method for MTBC and broth microdilution for NTM; and quality control (QC) protocols for each organism category. Testing and reporting recommendations and principles of QC procedures apply to use of commercial shorterincubation broth systems that have been cleared by the US Food and Drug Administration (FDA) for testing MTBC, as well as the reference methods.