血清1型鸭疫里默氏杆菌灭活油乳剂疫苗的研制

Study on the inactivated oil-emulsion vaccine of serotype 1 Riemerella anatipestifer

为研究血清1型鸭疫里默氏杆菌(R.anatipestifer,RA)的灭活油乳剂疫苗,本研究将10株血清1型RA的临床分离株经腿部肌肉注射7日龄雏鸭进行动物体内复壮,结果表明所有被测菌株均具有较强的毒力,易感雏鸭致死率100%。对其中3株RA分离株CH3、WJ4和YL4的毒力测定结果表明其半数致死量(LD50)分别为2×108cfu、3.25×108cfu和2.37×106cfu。选取5株RA分离株分别制备灭活油乳剂疫苗,分别于5日龄和18日龄对樱桃谷鸭进行两次免疫后,免疫鸭能够产生高水平的RA特异性抗体,对2 LD50WJ4或CH3攻毒产生很好的保护效果,其中由CH3、CQ3和YXb12制备的灭活油乳剂疫苗对攻毒的保护率高达100%。

Riemerella anatipestifer infection is a contagious disease of ducks,goose,turkeys and various other birds,and has caused the highest mortality among duck diseases.Serotype 1 is one of the most prevalent serotype of R.anatipestifer infection.To efficient control the infection,we developed the inactivated oil-emulsion vaccines of serotype 1 R.anatipestifer.In this study,ten isolates of serotype 1 R.anatipestifer were injected intramuscularly into 7-day-old Cherry valley ducklings to restore the bacterial virulence and the bacteria re-isolated from the inoculated ducklings were used as seed bacteria.The median lethal dose（LD50） of isolates CH3,WJ4 and YL4 were determined as 2×108 cfu,3.25×108 cfu and 2.37×106 cfu respectively.Five isolates of the R.anatipestifer were used to prepare inactivated oil-emulsion vaccines,respectively.Cherry valley ducklings were immunized twice subcutaneously at 5 and 18-day-old,respectively,and all the ducklings developed high titers of specific antibodies against R.anatipestifer.The ducklings immunized with CH3,CQ3 or YXb12 vaccine were 100% protected from the challenges of 2LD50 of WJ4 or CH3.