Antigenicity of lateral flagella of Vibrio parahaemolyticus: existence of two distinct antigenic determinants in a flagellum.

Cells of Vibrio parahaemolyticus treated with Formalin agglutinated with anti-lateral flagella antiserum. On the basis of agglutination tests, antigens of lateral flagella were divided into three groups. HL1, HL2, and HL3. However, in gel diffusion tests, flagellins prepared from strains belonging to different groups showed a common antigenicity. It is assumed that these results are due to the existence of two distinct antigenic determinants in the lateral flagella. One of them exists on the surfaces of the flagella and is responsible for H-agglutination, and the other exists inside the flagella and is exposed when the flagella are solubilized to flagellin monomers.