Safety and efficacy of an avirulent live Salmonella choleraesuis vaccine for protection of calves against S dublin infection

摘要: OBJECTIVE To evaluate the safety and efficacy of avirulent live Salmonella choleraesuis strain 54 (SC54) as a vaccine to protect calves against salmonellosis caused by S dublin. ANIMALS 40 head clinically normal 3 5-week-old male Holstein that were culture negative for sp. PROCEDURE Calves randomly assigned 4 test groups 10 each. Group 1 received 8.5 x 10(7) colony-forming units (CFU) SC54 SC. Groups 2 1.13 10(9) CFU SC54, SC intranasally, respectively. saline solution control. All challenge exposed orally with 1.74 virulent dublin 14 days after vaccination. Clinical signs shedding monitored 28 necropsied, organs cultured sp exposure. RESULTS had slightly high rectal temperature exposure resulted in mild clinical salmonellosis. vaccinated significantly (P < 0.05) lower temperature, fecal dublin, recovery from necropsy. was not recovered or blood samples collected vaccination injection site at CONCLUSIONS given intranasally safe reduced bacterial oral CLINICAL RELEVANCE has potential an effective aid prevention calves.