Bacteriophage inhibition in staphylococci.

The inhibitory effect of high-titre preparations of phage 47 on certain strains of Staphylococcus aureus belonging to phage group I11 was produced with a phage: cell ratio of approximately 1 : 1. Staphylococci showing inhibition by preparations of phage 47 were converted to phage sensitivity by lysogenization with a phage derived from a strain sensitive to phage 47. Multiplication of phage 47 in lysogenized clones was compared with that in the original inhibited strains. This showed that inhibition was due to a phage/cell interaction in which most of the infected cocci were killed; a minority produced a few phage particles in smaller numbers with a longer latent period. INTRODUCTION