[Methods for differentiation of streptococci: comparison of serological, biochemical methods, triple- and camp-test...

Methods for group classification of beta-hemolytic streptococci were compared: biochemical versus serological techniques as well as Triple- and CAMP-Test. Attention was mainly put to the Phadebact streptococcus test, based on the co-agglutination principle which is intended to differentiate groups A, B, C and G. This test is easy to conduct and allows grouping within minutes. Classification was done with 50 strains of clinical isolates. Approximately 88% of the strains were identified as group A and B which are the most important in human streptococcal infections. The co-agglutination gave false results with 6 strains (8%), one of which was group A. The others turned out to be S. milleri, they could be identified only by the Lancefield precipitin test. In cases where several Phadebact antisera lead to an agglutination of one strain, the questionable result must be verified by conventional methods.