Abstract
Antigenic characterization ofP. pneumotropicaderived from mice and rats were serologically investigated by use of hyperimmune rabbit sera against mouse strain M 1 and rat strain R 1 and absorbed sera m-1 and r-1 which were prepared by absorbing anti-M 1 serum with strain R 1 and anti-R 1 serum with strain M 1, respectively. All of 13 mouse strains employed were agglutinated with both anti-M 1 and anti-R 1 sera, but their agglutination titers with anti-M 1 serum were usually higher than those with anti-R 1 serum. Agglutination test of 13 rat strains with two antisera showed results converse to those of mouse strains. On the other hand, all the mouse strains were agglutinated with absorbed serum m-1 but not with absorbed serum r-1, while quite converse results were obtained with all the rat strains. Antigens reactive with the absorbed sera were remarkably destroyed by heating at 100°C for 1 hour and treating with 1 N HC1, suggesting to be capsular antigens of bacterial cells.
