Production of precipitating antibodies in chickens infected with Salmonella gallinarum.

Vaccination of 10 days old chicken with a live relatively avirulent S. gallinarum induced antibodies against the main antigens of the pathogen, namely, its proteins. Precipitations in agar gel were obtained against the free proteins and the protein conjugated in the somatic antigen of S. gallinarum and against antigens from the related S. enteritidis. Antipolysaccharide antibodies were induced in small quantities which were however sufficient to allow their identification with the agar-gel-diffusion technique.