鸡病原性大肠杆菌（O_2）亚单位疫苗的研究

STUDIES ON THE SUBUNIT VACCINES OF ESCHERICHIA COLI(SEROTYPE O2)PATHOGENIC TO CHICKENS

试验提取并纯化了鸡病原性大肠杆菌血清型（Ｏ２）的菌毛，并电镜观察了菌毛及菌毛表达。提取了鸡病原性大肠杆菌血清型（Ｏ２）荚膜多糖及菌体可溶性蛋白质，电镜观察了提取过程中荚膜、细胞壁以及胞内物质等细菌结构变化。将提取的菌毛、荚膜多糖和灭活的菌体作为抗原，蜂胶作佐剂，制成蜂胶疫苗，免疫鸡只，于７周龄进行同源攻毒保护试验，从保护指数、细菌分离和病变级数三方面比较了３种疫苗的免疫效果，试验结果表明：荚膜疫苗效果最好，菌体疫苗次之，菌毛疫苗最差；疫苗交叉保护试验表明菌毛疫苗和荚膜多糖疫苗都有血清型特异性而无明显交叉保护力。并利用微量凝集试验检测这３种蜂胶疫苗的抗体消长情况。

The pili of Escherichia coli(serotype O2)pathogenic to chicken were collected,roughly purified and observed under the transmission electron microscope(TEM).The polysaccharides of capsules and the soluble protein of E.coli werealso extracted,and the structural changes of E.coli which occurred during theextraction were observed under TEM.With propolis as adjuvant,the antigens(the collected pili,the extracted polysaccharides of capules and inactivatedwhole bacteria) were used to make three vaccines respectively.Throughchallenging 7-week-old broilers with the same serotype bacteria,the results ofthe protection index,bacteria isolation and lesion score showed that,the cap-sules polysaccharides vaccine was the best of the three,the inactivated wholebacteria vaccine came next,and the pili vaccine third.But 7-week-old broilerschallenged with the different serotype bacteria could not be protected.Theantibody levels of chickens induced by these three vaccines were measured bythe microplate agglutination test.