Cord formation in a clinical Isolate of Mycobacterium abscessus

Abstract

The species belonging to Mycobacterium tuberculosis complex (MTC) display characteristic serpentine cord formation in liquid cultures. The factor responsible for the cord formation is trehalose-6,6-dimycolate (TDM), a component of the mycobacterium cell wall that is responsible for MTC virulence. Thus cord formation is considered a definitive diagnostic character of MTC. Microscopic observation drug susceptibility assay (MODS), based on this character, is widely used for identification of multi drug resistant tuberculosis (MDR-TB).