Antigenicity of bdellovibrios.

Antigenic relationships between 12 locally isolated bdellovibrios and 3 established reference strains (109D, 6-5-S, and UKi2) were investigated. Antigenicity of the strains was examined by use of the micro-complement fixation test, the serum and complement bactericidal test, and the immunodiffusion test. Antisera were prepared against one of the local strains (MS7) and against one of the established reference strains (UKi2). The complement fixation titers suggest a close relationship among all strains. Immunodiffusion tests produced lines of identity between the homologous strain MS7 and all other strains. It is suggested on the basis of these results that bdellovibrio may possess a common antigen.