Serological relationship between a large Babesia found in Japanese cattle and Babesia major, B bigemina and B bovis.

Immunofluorescent methods were used to study the serological relationships between a Japanese Babesia species and three other Babesia species (B major, B bigemina and B bovis). All the sera were obtained at intervals from five splenectomised calves each infected experimentally with five strains of the four parasites. The antibody titre of each serum was determined by the use of homologous and heterologous antigens. The reactions between homologous antigens and their serial antisera were consistently higher than those obtained with heterologous antigens. It was concluded that the Japanese Babesia species (Miyake strain) was distinguished from B major (British and Dutch strains), B bigemina (Kochinda strain) and B bovis (Miyara strain).