AN EXPERIMENTAL STUDY OF THE VACCINE PROPERTIES OF A BR. ABORTUS VARIANT, OBTAINED UNDER THE EFFECT OF BRUCELLA TB BACTERIOPHAGE
ARMY BIOLOGICAL LABS FREDERICK MD
Pagination or Media Count:
A culture of Br. abortus No 84-C, obtained as a result of the influence of TB phage on the fully virulent culture of Br. abortus No 146, was a persistent R-variant with a weakened virulence and pathogenicity. Following administration to guinea pigs in a dose of 1 billion microbial cells the No 84- C culture of Br. abortus took root easily in the organism of the animals and caused benign pathomorphological changes, which indicated a weakly expressed vaccine process and which was preserved for 2 months. Following administration to guinea pigs of 2 billion microbial cells of this culture a 100 nonsusceptibility was observed to 2 and 5 infecting doses of a virulent culture of the melitensis species and this was preserved for a period of 6 months period of observation increasing the dose of infection during the period of the nonsterile immunity phase led to a break in it in 50 of the guinea pigs, however the index of infection in the vaccinated animals was significantly lower than in the control, which indicated the presence of a partial immunity in them. The culture of Br. abortus No 84-C sensitized guinea pigs comparatively weakly. As a result of the peculiarity in the antigenic structure of this culture the titers of the reaction with the Wright antigen in the vaccinated guinea pigs were significantly lower than with a homologous culture.