The immunity to Salmonella gallinarum infection in chickens produced by live cultures of members of the Salmonella genus

Abstract

1. The immunity to Salm. gallinarum infection produced by injecting chickens with live cultures of different species of Salmonella and other bacteria has been studied.2. Salm. pullorum produced a complete immunity equal to that produced by Salm. gallinarum itself. The immunity evoked by 11 of 12 other Salmonella species belonging to group D, although substantial, was less complete. Three of four rough group D strains and an avirulent strain of B. coli produced no immunity. Although a considerable degree of immunity was produced by the fourth rough strain it was not equal to that produced by rough strains of Salm. gallinarum.3. Owing to their lethal nature, it was not possible to be definite about the extent of the immunity produced by two group B strains, Salm. typhi-murium and Salm. Chester, although it may have been equal to that produced by the group D strains.4. A slight but definite degree of immunity was produced by two group C and two group E Salmonella cultures. Since this immunity was no better than that possessed by chickens previously infected with either Pasteurella septica or Staphylococcus aureus, it was considered to be non-specific in character.