A Study on Hemolytic Streptococci (Group A, B, C and G) Isolated from Throat of the Middle-Aged and Advanced-Aged

Hemolytic streptococci were isolated from throat of middle-aged and advanced-aged and these organisms were classified into groups A, B, C and G. 1) Persons 15 to 39 years old were included in one group and persons from 40 years of age upward were divided into 5 groups every 10 years. Comparison of these groups were done. Generally, group B organisms were most often isolated. The detection rate of group B organisms was higher in the older age group. The detection rates of group A and G organisms were approximately equal, but both organisms were isolated from a few persons. No organism of group C was isolated from males, while only two strains belonged to group C organism were isolated from females. 2) A number of strains of group A hemolytic streptococci were isolated from school children, particularly in the lower classes. But the proportion of group B organism to isolated streptococci showed an increase in upper classes, noticeably in females. 3) For middle-aged and advanced-aged, blood samples were obtained simultaneously on examination of the throat, and ASO value and ASK titer were determined. ASO values were higher in persons infected with groups A, C or G organisms than in persons infected with group B organism or no hemolytic streptococcus. ASK titers revealed a similar results to ASO values, though the relation between ASK titers and isolated hemolytic streptococci was less positive.