Role of Bursa of Fabricius in Chicken Resistance to Salmonella typhimurium

Abstract

SUMMARY Surgically bursectomized and control birds were inoculated intraperitoneally with Salmonella typhimurium and necropsied 3 to 48 hours later. Salmonella counts in artificially induced abdominal fluid at necropsy at 6 hours were significantly greater in bursectomized than in unbursectomized birds, indicating an active role for the bursa of Fabricius in the immune response to parenterally inoculated salmonellae. S. typhimurium was inoculated via the rectum into the ceca of bursectomized and control birds. The groups did not differ in salmonella counts in cecal contents at 24 and 48 hours, but fluorescent antibody examination of frozen sections of cecal walls showed tissue invasion to be at a statistically significant higher rate in bursectomized than in unbursectomized birds. Groups of bursectomized, thymectomized, and control birds were inoculated orally with either 10 or 108 organisms of S. typhimurium and inoculated intraperitoneally with 108 organisms 48 days later. Rectal swabs at intervals thereafter further indicated a significant role for the bursa of Fabricius in the immune response. No difference was noted between the thymectomized and control birds.