The Isolation of Salmonellae from the Bursa of Fabricius of Chickens Latently Infected with these Organisms

A nalidixic acid resistant mutant of Salmonella typhimurium was isolated more frequently from the Bursa of Fabricius than from the caecal contents, caecal tonsil, liver or spleen of chickens that had been given a culture of this mutant by mouth. Salmonellae were also isolated more frequently from the Bursa than from the caecal contents of naturally infected chickens.