Investigations on the typing of staphylococci by means of bacteriophage I. The origin and nature of lysogenic strains

Abstract

1. Investigations have been carried out on the bacteriophage method of typing staphylococci developed by Wilson & Atkinson (1945).2. Strains previously considered as belonging to one phage type, type 42D, or as untypeable, were classified into a number of types by the use of additional phages. This further classification was rendered possible by the acquired phage resistance of some of the strains. All the resistant strains were lysogenic.3. It was possible to produce a resistant variant of a strain to two phages. Some of these resistant variants carried both phages. Others could be demonstrated to be carrying only one phage.