鸡大肠杆菌多价自家灭活菌苗的研制和应用初报

Studies on Preparation and Application of Multivalent Inactivated Vaccine against Avian Colibacillosis

从11个血清型为O_1、O_2、O_(78)的标准菌株及地方分离的埃希氏大肠杆菌(Escherichia coli)中筛选出6个强毒菌株,作为制苗基础菌株,并加入发病鸡场的自家分离株,一起作为制苗菌种。干酵母肉汤中培养18～24h,甲醛灭活后,制成鸡大肠杆菌多价自家灭活铝胶苗。试验证实,该苗接种雏鸡0.5ml.成鸡1ml,无毒副作用。鸡只免疫后,对同型菌株近期攻毒的保护半为100％;现地应用结果表明,鸡只免疫后12周,血清中抗体平均凝集价为1:26.4,高于免疫临界线,并且鸡群健康状况稳定,增重加快,饲料利用率和产蛋率增加。

Six of highly pathogenic Escherichia coli(E. coli) including serotype O_1,O_2,O_(74),O_(78) were selected from 11 isolates as basic bacteria. These bacteria and the bacteria isolated from farms,where colibacillosis had broken out,were cultured in yeast broth for preparing the vaccine. The laboratory experiment confirmed that there were no side effects from the use of the vaccine on birds. High levels of antibody was defected in chicken' s serum 12 weeks after vaccination. 100% (10/10) of the inoculated birds were survived from the near challenging with homologous bacteria. Clinical tracing observation showed that the vaccinated chickens gave lower rate of mortality and feed-consuming, higher rate of egg-laying and weight gaining compared with unvacinated ones.