Studies on efficacy of recombinant R7 protein as immunogen for vaccine and as antigen for detection of antibody against Leucocytozoon caulleryi infection in chickens

摘要

Chicken leucocytozoonosis, caused by infec tion with Leucocytozoon caulleryi, has been recognized in various Asian countries including Japan. Chicken leucocytozoonosis is an economically important disease for poultry industry, causing reduction of eggproduction, weight loss, and sometimes death. Exterminating Culicoides arakawae that transmits the parasite of the disease definitely prevents chicken leucocytozoonosis, However, not all poultry farms can carry out this measure because of problems suchas structure of henhouse, environmental factor, and also labor force expended on the preventive. Feed with anti protozoan additives is extremely effective against leucocytozoonosis. Although, the use of these drug resulted in sharp decrease in outbreak of the disease from 1,964, there have been problems with decreased drug sensitivity and government regulation of use of drugs for laying hens. Thus leucocytozoonosis has begun to occur frequently again. Therefore, it is necessary to establish immunological preventives against the disease. This paper shows the verification of efficacy of adjuvant-mixed vaccine that contains recombinant R7 (rR7) antigen derived from a component of outer membrane of second-generation shizont (2GS) of L. caulleryi in laboratory experiment and in field condition.