禽大肠杆菌外膜蛋白、脂多糖疫苗的免疫保护试验

为探讨禽源性大肠杆菌外膜蛋白 (OMPs)、脂多糖 (L PS)对禽大肠杆菌病的免疫保护作用 ,从禽源性大肠杆菌0 37株提取 OMPs、L PS后 ,分别以含 2、1mg OMPs的油乳剂苗于 2、4周龄时各 2次免疫易感鸡 ,在免疫鸡 5周龄时以 10 8菌落形成单位 (CFU) 0 37株攻毒 ,结果免疫后、临攻毒前 (5周龄 ) 2组鸡的平均体重分别为 0 .96 kg和 0 .87kg,攻毒后 2个组的免疫保护效力分别为 94.74%和 78.95 %;以含 0 .2 5、0 .12 5 mg L PS的油乳剂苗同法免疫后攻毒 ,结果免疫后、临攻毒前其平均体重分别为 1.10 kg和 0 .98kg,免疫效力分别为 36 .84%和 31.5 8%;以含 1.2 5 mg OMPs 0 .12 5 m g L PS的油乳剂苗同法免疫后攻毒 ,该组鸡相应日龄的平均体重为 0 .88kg,免疫效力为 84.2 1%;以含 2 .5× 10 9CFU/ m L 灭活的全菌油乳剂苗免疫后攻毒 ,该组鸡 5周龄时的平均体重为 0 .88kg,免疫保护效力为 78.95 %。上述结果表明 ,OMPs是禽大肠杆菌病的主要免疫保护性抗原 ,而 L PS为次要免疫保护性抗原。

Immunogenicity of Oil-emusified Outer Membrane Proteins and Lipopolysaccharides of Escherichia coli against Homologous Challenge

Immunogenicity of oil-emusified vaccines with inactivated outer membrane proteins(OMPs) and/or lipopolysaccharides of avian Escherichia coli(037 strain,O78 serotype) against homologous challenge was investigated.Chicks were vaccinated intramuscularly twice at two and four weeks of age with oil-emusified vaccines containing 2 micrograms and 1 micrograms of OMPs per dose,and challenged at five weeks of age with 10 8 live cells of the homologous strains,the mean body weight of chicks after these 2 vaccinations and immediately before challenge(five weeks of age) was 0.96 kilograms and 0.87 kilograms respectively;and the percentage of immune protection of which was 97.74% and 78.95% respectively.Those vaccinated twice with oil-emusified vaccines containing 0.25 micrograms and 0.125 micrograms LPS per dose,and challenged in the same way,the mean body weight of these chicks immediately before challenge was 1.10 kilograms and 0.98 kilograms respectively;and the percentage efficacy was 36.84% and 31.58% respectively,chicks were vaccinated intramuscularly twice at two and four weeks of age with oil-emusified vaccines containing 1.25 micrograms OMPs and 0.125 micrograms LPS per dose,and challenged in the same way,the mean body weight of these chicks after these 2 vaccinations and immediately before challenge(five weeks of age) was 0.88 kilograms,and the percentage efficacy was 84.21%,while those vaccinated twice with oil-emusified vaccines containing 10 10 colony-forming-unit(CFU) inactivated cells per dose,the mean body weight of those was 0.88 kilograms,and the percentage efficacy was 78.95%.These results revealed that outer membrane proteins would be main protactive antigens of avian Escherichia coli,and lipopolysaccharides played a partialy role in the immune potection of avian colibacillosis.