Abstract: In this study，Eimeria tenella YuFu（ETYF strain）was isolated from a broiler farm in YuFu city，Guangdong Province. The methods of animal passage，microscopy，and PCR were used to identify Eimeria tenella. Coccidia ETYF species and its biological characteristics such as minimum prepatent period，oocyst excretion pattern，pathogenicity，and pathogenicity were monitored. The results showed that the minimum prepatent period could be continuously monitored 144 hours after the chickens were infected with ETYF strains of coccidia；Among them，the ET?3 group（30000 piece/ bird dose）had the highest peak at 168～174 hours after infection with ETYF，and the total number of oocyst excretion reached the largest during this period，reaching as high as about 14.47 million piece /dose. The optimal inoculation dose was 10000?30000 piece /bird dose；dead chickens appeared in ET?5 （50，000 piece /bird dose）and ET? 10（100，000 piece /bird dose），and the pathogenicity dose was 5.0×104 piece /bird dose. This study provides data support for subsequent drug screening and vaccine development. which has certain significance for the control of chicken coccidiosis.

Key words: Eimeria tenella； Minimum prepatent period； Biological characteristics； Pathogenicity

摘要： 利用单卵囊分离技术、动物传代、显微镜镜检、PCR扩增等方法，对分离自广东云浮 鸡场的柔嫩艾美耳球虫（Eimeria tenella YuFu，ETYF株）进行研究，明确其卵囊指数、潜隐期、 致病力、排卵囊规律等生物学特性。结果发现：该虫株卵囊平均大小为22.34 μm×19.21 μm，卵 囊指数为1.16±0.17，最早潜隐期为144 h；不同感染剂量组排卵囊高峰期不一致，主要集中在 162?180 h，感染3万个/只剂量组排卵囊总量最高，达1447万个/只；明确其最适卵囊接种剂量 为1~3万个/只；感染5万个/只ETYF孢子化卵囊后出现死鸡，明确其最低致死剂量为5万个孢 子化卵囊，且感染剂量越大，鸡肠道的病变越严重。本研究为后续药物筛选和疫苗研发提供 数据支持，对防治鸡球虫病具有一定的研究意义。

关键词: 柔嫩艾美耳球虫； 潜隐期； 生物学特性； 致病