Mycobacterium tuberculosis Complex

Abstract

Tuberculosis (TB) is caused by a group of closely related slowly growing mycobacteria, collectively named the Mycobacterium tuberculosis complex (MTBC). Members of the MTBC have undergone several taxonomic reclassifications, which has resulted in confusing nomenclature. Mycobacterial culture is currently considered the reference standard for MTBC detection. Until the early 1990s, typing of MTBC strains was limited to mycobacterial phage typing and drug resistance patterns, methods which have low discriminatory power that have been replaced by molecular genotypic methods. Antimicrobial susceptibility testing is a critical element of the MTBC laboratory workup. While cell‐based immunodiagnostics, such as tuberculin skin testing or interferon‐gamma release assays, can be used as part of establishing a diagnosis of active TB disease, they are mainly used as tests for latent TB infection and to determine exposure to TB.