Oxidative Stress Increases Susceptibility of Mycobacterium tuberculosis to Isoniazid

Oxidative stress increases susceptibility of Mycobacterium tuberculosis to isoniazid.

Isoniazid is a first-line antibiotic used in the treatment of infections caused by Mycobacterium tuberculosis. Isoniazid is a prodrug requiring oxidative activation by the catalase-peroxidase hemoprotein, KatG. Resistance to isoniazid can be obtained by point mutations in the katG gene, with one of the most common being a threonine-for-serine substitution at position 315 (S315T). The S315T muta...

A simple blood medium for determining the susceptibility of Mycobacterium tuberculosis to isoniazid (isonicotinic acid hydrazide).

In previous studies (Tanrhis and Frisch, 1951a,b) it was found that a human blood medium was satisfactory for determining the susceptibility of Mycobacterium tuberculosis to streptomycin. This investigation was undertaken to determine whether the same medium would be suitable also for performing isoniazid susceptibility tests, and to compare it with the American Trudeau Society (Report of the C...

Blood Agar Validation for Susceptibility Testing of Isoniazid, Rifampicin, Ethambutol, and Streptomycin to Mycobacterium tuberculosis Isolates

In recent studies, it was shown that blood agar can be used at least as effectively as Löwenstein-Jensen medium for growing Mycobacterium tuberculosis. It was also shown that susceptibility testing can be performed on blood agar. Additional validation of blood agar was performed on regional M. tuberculosis isolates from Turkey to determine critical concentrations of isoniazid (INH), rifampicin ...

Minor Contribution of inhA-15 Mutations to the Rapid Detection of Isoniazid Resistance in Mycobacterium Tuberculosis Isolates

Resistance to rifampicin and isoniazid in strains of Mycobacterium tuberculosis.

Drug susceptibility studies on strains of Mycobacterium tuberculosis isolated from widely different populations of patients and tested by two different techniques indicated that all 55 strains resistant to rifampicin were also resistant to isoniazid, while many strains resistant to isoniazid were found to be susceptible to rifampicin. This observation, which has as yet unknown laboratory and cl...