小鸡鸡白痢免疫抗体水平与抵抗人工发病关系的探讨

Study on correlation between the antibody levels of inactivated vaccine of salmonella pullorum and artificial infection with field isolate

采用鸡白痢油乳灭活疫苗分别对7日龄雏鸡进行1次、2次或3次免疫,获得鸡白痢抗体水平分别为0、1:2、1:4、1:8、1:16、1:32的雏鸡群,对各抗体水平雏鸡群人工感染鸡白痢沙门氏菌,每天通过观察雏鸡的精神、食欲、饮欲、粪便等症状情况和发病死亡鸡只的病理变化衡量,雏鸡不同鸡白痢免疫抗体水平与抵抗能力的关系。结果表明:人工感染鸡白痢强毒菌株后,0抗体(非免疫)雏鸡攻毒后72 h开始出现发病死亡,病鸡拉白色稀粪,心肌形成结节,肾肿大苍白,盲肠肿胀形成"肠芯;"1:2至1:32抗体水平小鸡,部分鸡只出现精神萎顿、拉白色粪便,其严重程度随着抗体水平的提高而减轻,无死亡鸡只。实验结果表明鸡白痢免疫抗体可有效抵抗强毒感染,在1:32免疫抗体水平以内,雏鸡抗感染的能力随着免疫水平的提高而增强。

7-day-old chickens were inoculated with oil-adjuvant emulsified inactivated vaccine of Salmonellar Pullorum for one,two or three times resepectively,and chickens with different antibody levels detected by plate agglutination test i.e.0,1∶2、1∶4、1∶8、1∶16、1∶32 were grouped.Each group was artificially challenged with Salmonellar Pullorum field isolate,and healthy conditions such as appearance,orexis,feces condition,and mortality were recorded as evaluation for the immune effects of inactivated vaccine.The results showed that some chickens without antibody died within 72 hours,along with white watery diarrhea,tubercles formed in myocardium,renal tumefaction and internal solidification in cecum.The mortalities of the groups with antibody between 1∶2 and 1∶32 were null,and the less clinical symptoms were found with higher antibody levels.This suggested that specific antibody was effective againt challenge with field isolate.