title: Comparison of bacteriostatic and bactericidal activity of isoniazid and ethionamide against Mycobacterium avium and Mycobacterium tuberculosis.
abstract: Minimal inhibitory and bactericidal concentrations (MIC and MBC) of isoniazid and ethionamide were determined in 7H12 broth in experiments with 68 Mycobacterium avium strains and 14 wild drug-susceptible M. tuberculosis strains. MICs of isoniazid for M. tuberculosis were from 0.025 to 0.05 microgram/ml, and for M. avium from 0.6 to greater than 10.0 micrograms/ml. MICs of ethionamide for M. tuberculosis were from 0.3 to 1.25 micrograms/ml, and 42.7% of M. avium strains were within the same range. Isoniazid and ethionamide were highly bactericidal against M. tuberculosis, but they had very low bactericidal activity against M. avium.
authors.affiliation: National Jewish Center for Immunology and Respiratory Medicine, Denver, CO 80206.
authors.forename: L B
authors.initials: LB
authors.lastname: Heifets
authors.forename: P J
authors.initials: PJ
authors.lastname: Lindholm-Levy
authors.forename: M
authors.initials: M
authors.lastname: Flory
mesh_terms: D015169:Colony Count, Microbial; D004305:Dose-Response Relationship, Drug; D005000:Ethionamide / Q000494:pharmacology*; D007538:Isoniazid / Q000494:pharmacology*; D009162:Mycobacterium avium / Q000187:drug effects*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D009994:Osmolar Concentration; D011874:Radiometry
chemical_list: D005000:Ethionamide; D007538:Isoniazid