Groups of mice were immunised against Salmonella typhimurium with heatkilled (HK) and acetone-killed (AK) vaccines or with their ultrasonic or Mickledisintegrated forms and subsequently challenged by the oral or intraperitoneal routes. All six vaccine preparations conferred statistically significant protection against intraperitoneal challenge as measured by reduced mortality, lowered infection rate and prolonged survival. Of the six vaccines, only the Mickledisintegrated HK vaccine significantly reduced the mortality rate of mice challenged by the oral route.
Filtered bacteria-free extracts of homogenates of infected mouse liver conferred active immunity against a massive intraperitoneal challenge, but similar extracts of normal liver or of spleen from normal or infected animals were without effect.
KawakamiM.,
OsawaN.,
MitsuhashiS.1966; Experimental salmonellosis. VII. Comparison of the immunizing effect of live vaccine and materials extracted from Salmonella typhimurium. J. Bact 92:1585
OlitzkiA. L.,
GodingerD.1963; Comparative studies on Salmonella typhi grown in vivo and in vitro. III. The immunizing potencies of acetone-killed vaccines prepared from in vivo- and in v/Vro-grown bacteria and the immunizing potency of substances isolated from infected organs. J. Hyg., Camb 61:353