<prompt> Which of the following is most active against both dormant non-dormant bacilli -PyrazinamideRifampicinStreptomycinINH  <response>: Ans. is b i.e., Rifampin Isoniazid is bacteriostatic for resting bacilli, but is bactericidal for rapidly dividing microorganisms. o The bactericidal action of rifampicin covers all subpopulations of TB bacilli. 