The in vitro intracellular growth of various species of salmonellae tested by the roller tube technique. using rabbit peritoneal macrophages was compared with their pathogenicity which was examined by intravenous and intraperitoneal inoculations into rabbits. Strains of S. choleraesuis, S. enteritidis, S. typhimurium and S. paratyphi B showed apparent intracellular growth, while no growth could be observed with S. paratyphi A, S. typhosa and Escherichia coli (0-55). Among the former strains, S. paratyphi B showed a particular microscopic finding in which no marked degeneration or destruction of cells occured in spite of the rapid multiplication of organisms. When each one strain of the 4 species which multiplied intracellularly was inoculated into rabbits, only S. choleraesuis elicited typical typhoid infection with high fever and bacteremia, while the others showed only a slight pathogenicity with temporary fever and antibody formation. The granuloma formation in the liver was noted in rabbits inoculated with the 4 species. No sign of infection and pathological change could be found in rabbits inoculated with S. paratyphi A.
Lyophilized material, Dried Tuberculin or DT, prepared from the unheated and concentrated culture filtrate of human strain Aoyama-Bwas fractionated by the use of Zone electrophoresis employing starch as the suporting medium, and 4 fractions, i. e. one polysaccharide and 3 protein fractions I, II, and III were obtained. Each of them was electrophoretically single component. The protein fractions II and III were almost consisted of proteins and contained very small amount of other components. There was no remarkable difference between the fractions II and III in their chemical properties. The protein fraction I contained polysaccharide in almost the same amount as protein.
A simple method for isolation and purification of Myc. lepraemurium from the infected tissues by treatment of trypsin (final concentration: 0.2%) with sodium desoxycholate (final concentration: 0.1%) was described. This procedure can be performed under sterile conditions and is harmless for the infectivity of the bacilli. The tissue component can be almost completely removed from the homogenate.