On the Specificity of the Desoxyribonucleic Acid Which Induces Streptomycin Resistance in Hemophilus

Abstract

If two microorganisms are to exchange genetic material which produces a heritable change, it is alleged that they must be closely related. This premise is supported by experimental work in bacterial viruses and in recombination in Escherichia coll. Heritable changes which have been induced in microorganisms by transformation have, prior to 1955, been reported only within a species of bacteria. In 1955, two short reports were published on interspecies induction of streptomycin (SM) resistance in Hemophilus (1 a, 1 b, 2). In each report, heterospecific transformation was of a much lower order of frequency than homospecific transformation.The designations "species" and "genus" used in this paper follow the nomenclature of the American Society of Bacteriologists (3). The precise connotations inherent in the term "species" when applied to higher organisms are not implied here. With this reservation, "species" and "genus" will be used in this paper without further qualifications.All evidence on transformation supports the premise that in pneumococci, H. influenzae, and meningococci the active component of the heredity determinant is desoxyribonucleic acid (DNA). The DNA which controls SM resistance in one serological type of H. influenzae has been shown capable of inducing resistance to SM in a heterologous type (4).These results stimulated an exploration of the specificity of the SM resistance transforming agent in an attempt to answer the question: Is the DNA which controls resistance in homologous type or species different from that which controls SM resistance in heterologous species of the genus Hemophilus? The genetic marker of resistance to high concentrations of SM was selected because it may appear in a single mutational step in many species of bacteria and can be induced in transformation experiments in a single step; also, a highly selective environment is available so that transformed cells can be not only detected but also counted accurately.

Transformation Reactions Between Pneumococcus and Three Strains of Streptococci

“…Based on present knowledge we do not believe that the relative efficiency or inefficiency of transformation reactions can serve as the basis for determining the relatedness of bacteria, as has been suggested by Leidy, Hahn, and Alexander in their studies of Hemophilus "species" (10). On the basis of transformation to streptomycin resistance, these authors suggest that H. influemae and H. parainfluemae are more closely related to each other than they are to//.…”

Transforming Activities and Base Contents of Deoxyribo-nucleate Preparations from Various Neisseriae

“…Leidy, Hahn & Alexander (1956, 1959 have applied an analysis of ratios of interspecific to intraspecific transformation to the taxonomy of the genus Haemophilus on the premise that such ratios reflect the degree of relationship of donor and recipient cells. Thus far, however, quantitative investigations of interspecific transformations have been restricted to streptomycin resistance; in view of findings by Green (1959) interpretation of interspecific transformation data involving this single characteristic should be made with caution.…”

A Taxonomic Study of the Genus Haemophilus, with the Proposal of a New Species

“…Although most authors state that the implicated organisms are identical to H. suis, it has unfortunately been the habit not to determine the exact growth requirements. However, during the past decade it has become clear that the overwhelming majority of strains named H. suis are haemin-independent, but otherwise agreeing in the characters described by Lewis & Shope (1931) (Leidy, Hahn & Alexander, 1956;Biberstein et al, 1963;Kilian, 1974). This finding stimulated Biberstein & White (1969) to propose the establishment of a new species H. purasuis with otherwise identical properties.…”