The study of hemolytic streptococci associated with scarlet fever

Abstract

The present work was undertaken subsequent to the work of Gordon, Bliss and of Tunnicliff in the study of hemolytic streptococci associated with scarlet fever. The object of the work was to study the agglutination of streptococci from the throats of patients with scarlet fever, and to study the phenomenon of agglutinin absorption with these bacteria. The strains were gathered from numerous sources. The technique was similar to that of Bliss. 1

The first part of the work consisted in a survey of scarlatinal patients designed to determine the percentage of agglutinable strains in acute cases of scarlet fever, and to determine the number of patients who had agglutinable streptococci in their throats at the end of the quarantine period. Forty acute cases were included in the first group. Hemolytic streptococci were isolated from 87.5 per cent of these throat cultures. 74.3 per cent of the strains isolated from these acute cases were agglutinated by immune sera prepared with two scarlatinal strains. Among the convalescents, streptococci were found in 47.3 per cent. 55.0 per cent of these strains could be agglutinated with scarlet immune sera.

The second part of the work consisted in cross agglutination reactions between strains obtained from scarlet fever occurring in several large cities of the United States and Europe. A series of strains obtained from a milk borne epidemic of scarlet fever, both from the throats and from the suspected milk, were included in the series. The strength of the reaction varied with the various combination of sera and strains, but in the main the cross agglutinations were consistent and strains obtained from conditions other than scarlet fever were not agglutinated.

The absorption of agglutinin was carried out at 55° C. Fresh immune sera and strongly agglutinable strains were necessary for agglutinin absorption.