HOST RANGE OF CERTAIN VIRULENT AND TEMPERATE BACTERIOPHAGES ATTACKING GROUP D STREPTOCOCCI.

Brock, Thomas D. (Indiana University, Bloomington). Host range of certain virulent and temperate bacteriophages attacking group D streptococci. J. Bacteriol. 88:165-171. 1964.-Host range studies with five bacteriophages isolated from sewage showed that a high degree of strain specificity occurred among the species Streptococcus faecalis, S. faecalis var. zymogenes, and S. faecalis var. liquefaciens. Certain phages were able to attack various members of these subgroups but not other members. A high degree of strain specificity was also found with respect to eight phages attacking strains of S. faecium. Many strains of this latter group were resistant to all the phages available. The only firm conclusion was that no phage attacked both S. faecium and S. faecalis strains. In several selected strains of the S. faecalis-liquefaciens-zymogenes group, resistance to several virulent phages seemed to be related to the presence of certain prophages in these strains. A search for transduction with the temperate phages was unsuccessful. Mutants of S. faecium 8043 resistant to certain growth-factor analogues showed unpredictable changes in resistance and sensitivity to two virulent phages.