Phages for various suipestifer strains differ both in their direct reactions and in their absorption effects.
Such studies with one of the suipestifer phages revealed the close parallelism of the specificities revealed by antibody and phage. With one exception, both sorts of reagents revealed the same subgrouping of suipestifer strains.
Other results point to the existence of further differences of strains within a particular subgroup.
For the diagnosis of the species suipestifer the suipestifer fraction in a polyvalent phage is less specific than phages for particular strains of the homologous group.
The property of any culture in its behavior to phage may be employed along with other criteria to aid in its identification. This is particularly significant for certain cultures which are resistant to phage action but, nevertheless, absorb specifically.
The nature of bacterial resistance to bacteriophage is discussed in terms of variation in antigenic composition.
Supported by a grant from the Wisconsin Alumni Research Foundation.