A number of hybridomas against different determinants of R. prowazekii were obtained by hybridization of splenocytes from BALB/c mice immunized with whole cells or soluble antigens of the organism. Some of the monoclonal antibodies bound to thermolabile species specific protein of R. prowazekii and did not react with R. mooseri antigens (monoclonal antibodies series B4/4 and A3). Monoclonal antibodies C5/2 and A3/2 reacted with group specific thermostabile antigen which is common for both R. prowazekii and R. mooseri. Monoclonal antibodies against species specific antigen were found to be of Ig G2a subclass. The monoclonal antibodies can be used to identify R. prowazekii and R. mooseri and solve the problem of differentiating Rickettsiae of typhus group.
