ABSTRACT
Biochemical characteristics employed to identify tuberculous and non tuberculous mycobacteria were evaluated. Tests for detection of nitrate reductase, catalase, gamma-glutamyl-transferase, niacin assay and growth on TCH media (2-thiophene carboxylic-acid hydrazide) were regarded of discriminating value. These tests have been applied to identification of 78 clinical isolates of mycobacteria. All strains were identified as Mycobacterium tuberculosis, that suggest the infrequency of human infections from Mycobacterium bovis and mycobacteria other than tubercle bacilli in our geographic area. It is also outlined that the gamma-glutamyl-transferase test constitute a rapid and simple assay for discriminating Mycobacterium tuberculosis from other closely related mycobacteria.
