【摘要】 笔者对新分离到的和缓艾美耳球虫进行了致病性和免疫原性的研究。结果表明雏鸡感染1 000和5 000孢子化卵囊表现正常,肠道没有肉眼可见的病理变化。20 000个卵囊感染引起轻微病变。100 000个卵囊和500 000 个卵囊感染则产生较为明显的致病作用,与不感染对照组相比增重分别为70．3％和56．8％,肠道外观也产生明显可见的病变,根据0-4分肠道计分标准,分别为1．43和2．37。所有实验鸡都没有出现死亡。该虫株免疫原性较强,一次免疫5 000个卵囊/只,就能够对200 000个卵囊/只感染产生坚强的保护作用。更多还原

【Abstract】 Experiments were conducted to investigate the pathogenicity and immunogenicity of a new isolated strain of E. mitis. Results showed that 21day-old male Luoman chickens appeared normal 6 days after infections with 1000 and 5 000 sporulated oocysts of E. mitis and no lesions were observed in the intestines. However, 100 000 oocysts and 500 000 oocysts were apparently pathogenic and the average weight gains were 70. 3% and 56. 8% respectively compared with that of the unimmunized group. The general appearances of the intestines were abnormal with the average intestinal scores of 1. 43 and 2. 37 respectively. Chickens immunized with 5 000 oocysts of E. mitis were completely protected against the challenge with 200 000 oocysts of E. mitis 2 weeks later.更多还原