Objective: Human Salmonellosis is one of the most frequently reported foodborne zoonoses in the European Union. The most common source of human infections is the consumption of poultry products. Besides management and hygiene practices vaccination of poultry livestock is seen as one way to reduce Salmonella infections in humans. Turkey flocks in Europe are frequently infected with Salmonella and until recently there was no live vaccine for turkeys available. The aim of the present study was to examine the development of humoral antibodies after repeated vaccination with a bivalent live Salmonella vaccine containing attenuated Salmonella Typhimurium and Salmonella Enteritidis strains. Furthermore the colonization of the caecum with the vaccine strains and their spread to liver and spleen as well as the course of their fecal excretion was observed.
Results: Antibody production was hardly detectable after the first vaccination but increased after booster vaccinations. Both the Salmonella Enteritidis and the Salmonella Typhimurium vaccine strain were reisolated from caecum contents and organ samples. After booster vaccinations the re-isolation rates were reduced. The shedding of the vaccine strains was most pronounced after the first vaccination.
Keywords: Immune response; Immunisation; Salmonella; Turkey.