Some Serological Relationships of the S, R, and G Phases of Bacillus salmonicida

Abstract

The cultural and pathogenic characteristics of British Columbia strains of Bacillus salmonicida have been recorded (Duff and Stewart, 1933), and the S, R, and G variants of the microorganism were later described (Duff, 1937). The present report deals with the application of reciprocal agglutinin absorption methods in an attempt to discover the serological connections between the S, R, and G phases. The work has been designed to elicit both the relationships existing between the variants recovered from individual strains, and also those existing between the variants of different strains. A total of 19 British Columbia strains have been examined. Of these, 8 have been subjected to full reciprocal tests (Krum-wiede, Cooper and Provost, 1925); the remainder have been tested in respect only to their agglutinability by suitably absorbed antisera. EXPERIMENTAL Origin of variants The S, R, and G variants were obtained by subjecting stock cultures (usually R) to serial growth in 0.25 per cent lithium chloride broth (Hadley, Delves and Klimek, 1931; Duff, 1937). The colonial distinction between the R and S dissociants was found to be most marked when platings from the broth series were made upon peptone-meat extract medium containing 1.5 per cent sodium chloride and 0.8 per cent agar. G-phase cultures