Preparation of anti-Vibrio parahaemolyticus IgY and its cross-reaction with different serotype strains

In order to investigate the potential role of immunoglobulin of egg yolk (IgY) in the prevention and control of Vibrio parahaemolyticus in Litopenaeus vannamei culture, we prepared three V. parahaemolyticus strains from serotypes (O1: KUT and OUT: KUT) as inactivated vaccines and immunized against laying hens to prepare IgY, respectively. Then we evaluated the titer, inhibitory effect and cross reaction of anti-V. parahaemolyticus IgY by ELISA and tube agglutination tests. The results show that all the three strains induced high specific level of IgY. The trends of antibody agglutination titer and ELISA titer were similar, both reaching the plateau of antibody titer from 10 to 60 d after the fourth immunization, with agglutination titer above 1∶8 and ELISA titer above 1∶6 400. The prepared IgY showed strong cross-ELISA and cross-agglutination reaction with other V. parahaemolyticus for the same serotype, but had lower cross-ELISA reaction and no cross-agglutination reaction with other serotype strains. This study clarifies that V. parahaemolyticus can stimulate the production of high specific level of IgY in laying hens, but does not have cross-protective potency against different serotypes of strains, which provides references for the development and application of anti-V. parahaemolyticus IgY products.