Niacin, nitrate and pyrazinamide studies using Middlebrook 7H10 Broth.

An innovative and rapid method for testing mycobacteria was developed using Middlebrook 7H10 Tween Broth in place of conventional media. Niacin production, nitrate reduction and the breakdown of pyrazinamidase were determined in 198 mycobacteria isolates. Less than nine days were required to obtain positive test results, and the correlation of tween broth with conventional test methods exceeded 98%.