The emergence of strains resistant to the two most effective anti-TB agents isoniazid and rifampicin (multi-drug resistant, MDR), as well as to other second line antibiotics (extensively drug-resistant, XDR), poses a serious challenge to TB control today.
Tänapäeval on tuberkuloosi tõrjes raske probleem kahele kõige efektiivsemale tuberkuloosiravimile isoniasiidile ja rifampitsiinile resistentsete (multiresistentsete), samuti teistele teise põlvkonna antibiootikumidele resistentsete (ulatuslikult ravimresistentsete) tüvede tekkimine.