| Abstract: | Isolates of a Lancefield Group C organism, Streptococcus equisimilis, of sow reproductive tract and young swine joint origin were found to possess type-specific antigens. Capillary precipitin and immunodiffusion tests, done with acid extracts and cross-absorbed rabbit antisera, revealed four serotypes among 62 of 64 isolates. Extracts of two swine isolates of S. equisimilis and other Lancefield Group C strains including S. equi, S. zooepidemicus and three previously established types of S. equisimilis of human origin did not react with any of the four type-specific sera. Antigens responsible for type-specificity were heat-stable and sensitive to trypsin. |
