鸡体内减毒鼠伤寒沙门氏菌的繁殖和免疫反应

Colonization and immune responses of attenuated Salmonella typhimurium in chicken

初步研究了cya和crp双基因突变减毒鼠伤寒沙门氏菌 (Salmonellatyphimurium )在鸡体内的繁殖和免疫反应。 1、4或 7日龄肉鸡分别经口感染 10 8或 10 9CFU减毒S .typhimuriumX4 5 5 0 ,接种后 3～ 4周鸡体内特异性细胞和体液免疫达到最高峰。 4日龄口服 10 9CFU组免疫效果最佳 ,但 1日龄高剂量组表现增重降低及免疫抑制。 2 8日龄每鸡口服攻击 10 10 CFU强毒S .typhimurium 5 0 333,各免疫组保护率为 10 0 %。同时免疫鸡还能全部或部分阻止沙门氏菌在肝脏和脾脏的繁殖。接种后减毒S .typhimurium在泄殖腔的检出时间为 4周左右。

Broilers were infected with 10~8 or 10~9 CFU of attenuated Salmonella typhimurium X4550 per chicken by orally at 1,or 4,or 7-day-old,All vaccinated chickens were protected when they were challenged by 10^(10) CFU virulent S.typhimurium 5033 per chicken at 28-day-old.Body weight gaining was decreased and Immune function was suppressed when the chickens were infected 10~9 CFU bacteria at 1-day-old,but inoculating 10~9 CFU bacteria at 4-day-old could induce the best powerful immune responses.Colonization of Salmonella in liver and spleen was impacted fully or partially.The attenuated Salmonella could be found about 4 weeks in cloacal swas after inoculation.