Comparison of slide agglutination test (Phadebact) with counterimmunoelectrophoresis for detection of streptococcal group antigens.

Sera from mice infected with group B streptococci and culture supernatants of group B, A, and C streptococci were examined for the presence of group-specific antigens by the Phadebact slide agglutination (PSA) test and counterimmunoelectrophoresis (CIE). The results were correlated with the number of organisms present in the blood or in vitro cultures. The PSA test was slightly more sensitive than CIE.