<prompt> The primary reason for the use of drug combination in the treatment of tuberculosis isEnsure patient compliance with the drug regimenEnhance activity against metabolically inactive mycobacteriaDelay or prevent emergency of resistanceProvide prophylaxis against other bacterial infection  <response>: Ref-KDT 6e p745 The bacteria that cause tuberculosis TB can develop resistance to the antimicrobial drugs used to cure the disease. Multidrug-resistant TB MDR-TB is TB that does not respond to at least isoniazid and rifampicin, the 2 most powerful anti-TB drugs. ... In some cases even more severe drug-resistant TB may develop. 