摘要
从四川德阳某鸭场病死鸭肝脏中分离的DY9株细菌,经理化特性、16SrRNA核苷酸序列与cam基因检测,证明为鸭疫里默氏杆菌,并对其毒力与毒力稳定性等进行了测定。DY9株细菌对14日龄非免疫健康鸭的LD50大于2.3×1010CFU/0.5mL,但死亡鸭不具有纤维素性炎症病变,并未能回收到细菌;经敏感鸭体内连续传10代和经巧克力营养琼脂平板传30代后毒力未见显著改变;培养滤液不影响鸭胚成纤维细胞的形态;油佐剂灭活菌苗与活菌苗免疫鸭后14d攻毒分别获得100%和79.52%的相对保护率,21d时均为100%。以上结果表明,DY9株细菌为毒力稳定的鸭疫里默氏杆菌自然弱毒株。
Bacteria DY9 strain was isolated in Sichuan province from a dead duck.DY9 strain was investigated by biochemical reaction test,nucleotide sequence of 16S rRNA and cam gene.The results showed that DY9 strain was Riemerella anatipestifer（RA）and the 50% lethal dose（LD50）was more than 2.3×1010 CFU/0.5 mL for 14-day-old ducks.In animal assay,the dead ducks did not characterize fibrinous inflammation and there did not have RA in the livers.The RA did not recover virulence after 10 passages in ducks and not loss virulence after 30 passages in vitro culture in chocolate agar.Morphology of duck embryo fibroblast treated with culture filtrate of DY9 strain was not changed.At vaccinated 14 days,the oil-adjuvant inactivated vaccine and the live bacteria had the relative percentage survival（RPS）with 100% and 79.52% respectively,and at 21 days,they were both 100%.The results indicated that DY9 strain RA was low-virulence field strain,and the virulence was stabile.
出处
《中国畜牧兽医》
CAS
北大核心
2010年第6期141-144,共4页
China Animal Husbandry & Veterinary Medicine
基金
西南大学科技服务项目(2007F002)
西南大学硕士研究基金(2007S09)资助
关键词
鸭疫里默氏杆菌
自然弱毒株
分离鉴定
Riemerella anatipestifer
low virulence in field strain
isolation and identification
