Test Details: Drug susceptibility testing for Mycobacterium Tuberculosis from liquid MGIT culture is important for therapy guidance and surveillance of drug resistance. It is the most reliable method to determine antimicrobial resistance and susceptibility and has a good clinical correlation. Isoniazide is an antibiotic used in the treatment of mycobacterium tuberculosis infections as a first line drug. It is also used to prevent reactivation of TB by giving it as a combination therapy.