Humoral and cellular immune response in mice after infection with Salmonella typhimurium.

NMRI mice were infected orally with S. typhimurium. Specific antibody titers determined by indirect hemagglutination, and cellular immune response tested by blastogenesis transformation of lymphocytes and enhanced bactericidal action on Listeria monocytogenes were studied in relation to persistence of bacteria up to one year after the infection. About three weeks after the infection cell mediated immune reactions were no longer detected and in the course of a year detection of serum antibodies often failed despite persistence of Salmonella.