Studies on Transformations of Hemophilus influenzae

Abstract

A general method of determining the nature of the genotypes in mutants of transformable bacteria with similar phenotypes is discussed. The method is used to identify the genotypic patterns of three mutants of Hemophilus influenzae which are resistant to different levels of streptomycin. A strain resistant to 700 [mu]g per ml of the antibiotic was found to have 2 mutations at 2 unlinked, independent loci[long dash]presumably on different molecules of transforming DNA. These loci, when in separate cells, render them resistant to maximum levels of 10 and 100 ug per ml streptomycin respectively and are therefore designated as Sm10 and Sm100. When they enter the same cell they produce a resistance up to 700 [mu]g per ml streptomycin, so the cells are noted as Sm700.