抄録
Genetic studies have been made on the isoniazid resistance-system of Mycobac-terium tuberculosis var. hominis, strain Aoyama-B.
It has been suggested that the isoniazid resistance-system consists of two genes, a chief factor and a conditional factor. A lower level of resistance (up to 50 μg/ml.) is produced by mutation of one gene (INH-L) and a higher level of resistance (up to 400 μg/ml.) is produced by double mutations of two genes (INH-L and INH-h).
