The role of serum and biliary antibodies and cell-mediated immunity in the clearance of S-typhimurium from chickens

Abstract

The development of three parameters of immunity in response to a non-lethal infection of Salmonella typhimurium in adult chickens has been examined. Intravenous inoculation of 1 X 10(6) organisms established infection in the liver, spleen and intestinal tract of all birds; the organism persisted in these sites until day 9 of the infection, after which it was cleared rapidly from all sites. High levels of agglutinating and haemagglutinating antibodies were found in serum and bile 5 days after infection; they peaked at days 7 to 10, and detectable antibody was still present in both fluids 6 weeks after infection. The presence of this antibody did not appear to cause a significant reduction in organism numbers in any of the sites examined. Cell mediated immunity was detected at day 14. It is suggested that cells mediated immunity is responsible for clearance of the organisms from the tissues.