A GENETIC STUDY ON THE CYCLOSERINE-RESISTANCE OF YCOBACTERIUM TUBERCULOSIS VAR. HOMINIS

Abstract

Genetic studies on the cycloserine-resistance system of Mycobacterium tuberculosis var. hominis (strain Aoyama-B) have been conducted.
It has been suggested that there are two genotypes determining cycloserine-resistance, one determines resistance until 60 to 70 mcg and the other determines resistance until 100 to 200 mcg of cycloserine. Organisms having the wild genotype are able to survive on media containing below 20 mcg of cycloserine. Such mutants as capable of growing on media containing above 200 mcg of cycloserine have not been observed.
The authors wish to express appreciation to Dr. R. Katsunuma, Director of the Obuso National Sanatorium, and Prof. S. Hibino, Nagoya University, for their kind encouragement in the conduct of the study. The authors also wish to express their appreciation to Prof. I. Uchikawa for his kind advice.