Alteration in Transformability of Diplococcus Pneumoniae after the Acquisition of Genetic Determinants Inducing Resistance to Erythromycin.

Sirotnak, Francis M. (Sloan-Kettering Institute for Cancer Research, New York, N.Y.), Ramona B. Lunt, and Dorris J. Hutchison. Alteration in transformability of Diplococcus pneumoniae after the acquisition of genetic determinants inducing resistance to erythromycin. J. Bacteriol. 86:735-739. 1963.-The genetic alteration of a highly transformable (competent) recipient strain of Diplococcus pneumoniae by the transformation of at least two of three identified erythromycin-resistance determinants (Ery(a), Ery(b), Ery(c)) results in a marked decrease (Ery(a-b) recombinant) or complete loss (Ery(a-c) recombinant) in the ability to be transformed. The occurrence of transformable cells in cultures of the R6 Ery(a-b) recombinant strains, although greatly diminished, still varies during growth in a manner characteristic of the fully competent parent strain. Both Ery(b) and Ery(c) determinants appear to be linked to Ery(a). In experiments using P(32)-labeled deoxyribonucleic acid (DNA), data correlating DNA uptake with transformation show a decrease or loss in uptake capacity of the erythromycin-resistant strains.