Serological Properties of Extracts of Hæmolytic Streptococci prepared by Ultrasonic Vibrations

Abstract

IT has been shown¹ that in order to produce protective sera of high potency against hæmolytic streptococci the vaccines employed for immunization have to be prepared from cocci cultivated for a few hours only. While such young cocci are well capsulated, the capsules are lost after the early stage of growth. The assumption seemed therefore justified that an antigen contained in the capsular substance is responsible for the production of protective antibody. Since it is also known1 that this antigen is highly labile and easily altered by chemicals or excessive heat, in any attempt at its isolation a method must be used which interferes as little as possible with the constitution of the antigen. Disintegration of streptococci by sonic vibrations of audible frequency has previously been described by Chambers and Flosdorf², and Mudd and collaborators^3,4 have used this method for the extraction of labile antigen. The results of these workers have, however, no direct bearing on the problem of the streptococcal capsule as they employed ‘overnight’ cultures only in their investigations. It was thought that disintegration of the cocci by means of ultrasonic vibrations would liberate the antigen unaltered.