A comparative study on the pretreatment methods for the cultivation of Mycobacterium tuberculosis on LJ medium. Part I.

The sputa of 303 cases who were admitted at Ojha Sanitaurium Karachi were studied for comparing the efficacy and reliability of the three pretreatment methods including the standard method, and those recommended by Nassau (1958) and Becker (1916). Out of the total 223 cases were found to be positive after cultivation on LJ medium out of which 142 were found positive with ZNCF staining while in 81 cases no AFB could be detected. The number of cases found to be positive with standard method, Becker's method and Nassau's method were 117,131, and 147 respectively. As to the contamination, 58 were encountered with standard method, 25 with Becker's method and 84 with Nassau's method. 128 negatives were observed with the standard method, and 147 and 72 with Becker's method and Nassau's method respectively. The merits and demerits of the three methods are discussed.