Abstract
Genetic studies on the kanamycin resistance-system of Mycobacterium avium, original S-type Jucho strain, have been conducted by the population analysis method. The resulting conclusions are as follows:
There are multiple population structures of clones obtained by the first-step selection of the parent strain previously not exposed to any drug. The results suggest that there are multiple genotypes producing different population structures of clones.
The wild genotype produces resistance levels to kanamycin up to 0.4μg/ml. Resistance levels up to 1μg/ml. of kanamycin seem to be produced by mutations of the polygenic system. High resistance levels seem to be produced by a possible single gene mutation. There is a marked difference betweeen the streptomycin resistance- system and the kanamycin resistance-system of the test organism. The polygenic system for kanamycin resistance can produce only a limited levels of resistance (up to 1μg/ml.), while the multiple gene system for streptomycin resistance-system can do extremely high resistance levels.
