【摘要】 运用Ｊｅｆｅｒｓ（１９７５）选育法进行了Ｅ．ｂｒｕｎｅｔｉ早熟弱毒虫株的选育，经过连续七代的选育，获得了Ｅｉｍｅｒｉａｂｒｕｎｅｔｉ早熟弱毒虫株，该虫株的潜隐期为１０８ｈ，比Ｅ．ｂｒｕｎｅｔｉ亲本毒株提前了１２ｈ以上。免疫试验和致病性试验的结果表明Ｅ．ｂｒｕｎｅｔｉ早熟虫株具有免疫原性，对攻毒具有完全的保护作用。Ｅ．ｂｒｕｎｅｔｉ早熟虫株的致病力相对其亲本株大大降低。上述结果表明，Ｅ．ｂｒｕｎｅｔｉ早熟弱毒虫株可用于鸡球虫弱毒疫苗的研制。更多还原

【Abstract】 E brunetti was attenuated by passing the parasite in chickens as described by Jeffers and precocious strain of E brunetti was developed after 7 passages with prepatent period of 108 hours,which was 12 hours shorter than that of original strain of E brunetti The pathogenecity and Immunity of E brunetti precocious strain were studied,and the results showed that vaccination with precocious strain could completely protect the chickens which were challenged The pathogenecity of the strain was significantly decreased when compared with that of original strain These results indicate that precocious strain of E brunetti can be used as an attenuative coccidia vaccine更多还原