The Streptococci of Group D; the Serological Grouping of Streptococcus bovis and Observations on Serologically Refractory Group D Strains

Abstract

SUMMARY: The concentration of the group-specific substance in hydrochloric acid extracts by precipitation with ethanol has facilitated the serological identification of Streptococcus bovis and certain other serologically refractory streptococci as members of group D. The notorious difficulty of preparing potent group sera for Str. bovis was overcome by immunizing rabbits with organisms shaken with an abrasive in a magnetic vibrating machine. The relationship of Str. bovis to certain other streptococci and the chemical nature of the specific substance of group D are discussed.