Immunogenic and Chemical Properties of Fractions Prepared from Ten Types of Group A Streptococci

[摘要] Fractions of low toxicity have been prepared from 10 types of group A streptococci. Small amounts of these fractions confer active protection in mice against 100 to 1000 average lethal doses of homologous bacterial challenge. Passive protection in mice is demonstrated by rabbit antiserum to type 3 fraction.The Dick reaction in 6 out of 10 human beings changed from positive to negative after 3 injections of type 3 fraction totalling 155 mg. Pooled sera of certain individuals after immunization with type 3 fraction, showed passive protection in mice.Chemical analyses show that the ribonucleic acid appears to be distributed uniformly in both the cytoplasm and in the surface of the streptococcal cell, whereas the desoxyribonucleic acid is present in higher concentration in the surface.

[学科分类] 生物科学（综合）