The antigenic structure of Shigella alkalescens was studied, employing eight strains of different sources, and the following results were obtained:
Shigella alkalescens, when injected into rabbits, may readily induce the formation of specific agglutinins.
Any of the anti-Shigella alkalescens sera reacted with all eight strains of Shigella alkalescens.
This agglutination of suspensions of Shigella alkalescens by means of these anti-sera was obtained after short incubation (15 minutes) at 55°C.
Antisera for Shigella alkalescens may agglutinate some strains of Shigella paradysenteriae, Flexner indicating a common antigen in the two species. These anti-sera failed, however, to agglutinate Eberthella typhi, Shigella dysenteriae, Shiga or Shigella paradysenteriae, Duval-Sonne.
Agglutinin absorptions showed that Shigella alkalescens contains an antigen apparently characteristic of this species and at least one more in common with Shigella paradysenteriae, Flexner.
A bacteriophage for Shigella paradysenteriae, Flexner was ineffective toward six strains of Shigella alkalescens tested, but was effective toward seven out of eight strains of Shigella paradysenteriae, Flexner.
Patients infected with Shigella alkalescens may develop specific agglutinins.
Read at the 25th Annual Meeting of the American Association of Immunologists, at Atlantic City, May 2, 1938.