STUDIES ON THE ROUTINE IDENTIFICATION PROCEDURE FOR MYCOBACTERIA

Abstract

The test in the clinical laboratory should be done simply and reliably and the final results of the test would desirablly be brought out as early as possible. Considering those requirements, the following seven features were selected to be tested for the identification of clinical isolates of Mycobacteria: 1) colour tone of the colonies, 2) roughness of the colonies, 3) photoactive pigment production, 4) niacin production, 5) nitrate reduction, 6) heat stable phosphatase activity and 7) Tween hydrolysis. To fulfil the above described requirements, test paper methods were employed in cases of niacin test and nitrate reduction test, and the commercial reagent kit for blood chemistry was employed in case of the heat stable phosphatase test.
Since these tests except the roughness of colonies were carried out by reading the colour change, the results of these tests were read simply and reliably. In addition, every test could be done within a few hours except the Tween hydrolysis, and the species name of the tested strain could be brought out on the day of examination in many occasions. Dividing the above described test combinations into two steps, the author succeeded to identify various strains of Mycobacteria of typical characteristics, such as M. tuberculosis, M. kansasii, M. intracellulare (M. avium-intracellulare complex), M. scrofulaceum and M. fortuitum by performing five or six tests out of the above seven tests.
The test system herein described would contribute to the routine identification method of Mycobacteria in clinical laboratories.