Cross Protection Between Heterologous Agglutinogenic Types of Beta Hemolytic Streptococci

[摘要] A study was made of 43 strains of Lancefield's group A which when first tested failed to ferment lactose or fermented it slightly. Some of these strains later developed the ability to ferment lactose. The sub-group is designated “lactose deficient.”A correlation was found between lactose-deficiency and serologic grouping in type 18.A high degree of virulence was readily attained by all 5 lactose-deficient strains passed through mice.Protective serums prepared with lactose-deficient strains of types 14, 15, 18, and 19 all protected mice against infection with strains of heterologous types. The serum prepared with strain 654 of type 15 showed the broadest range, protecting mice against infection with 7 out of 10 heterologous strains tested.

[学科分类] 生物科学（综合）