肉鸡鹦鹉热衣原体的分离和鉴定

Isolation and Characterization of an Chlamydia Psittaci in Broiler

目的 确定鹦鹉热衣原体是否为导致肉鸡发生严重呼吸道疾病的主要病原。方法 对 2 0 0 1～ 2 0 0 2间北京、天津地区肉鸡流行的严重呼吸道疾病的鸡群进行血清学测定。取发病鸡的心、肺、肾脏组织固定、切片、染色 :发病鸡肺脏组织液接种 7dSPF鸡胚 ,收集 4～ 9d死亡鸡胚的卵黄囊膜 ,分别用碘染色、衣原体荧光染色 ;青霉素、磺胺嘧啶钠抑制分离的病原 ,观察SPF鸡胚发育。分离病原注射 15d商品肉鸡 ,复制病变。结果 发病肉鸡血清抗体出现 10 %～ 30 %阳性 ,分离病原荧光染色阳性 ,人工感染肉鸡后可以复制病变。结论 从肉鸡分离的病原可能是鹦鹉热衣原体 ,与大肠埃希菌混合感染是造成肉鸡呼吸困难、死亡升高的主要因素。

Objective Chlamydia psittaci is now suspected as a primary predisposing factor eliciting a sever respiratory syndrome. Methods The broiler blood samples suffered from respiratory symptom were screened in Beijing and Tianjing areas during 2001 to 2002.The lung, heart and kidney tissue from infected broiler were fixed,stained,implanted and observed under microscope; meanwhile the lung tissue suspension from infected broiler was inoculated into the SPF egg on day 7. The yolk membrane of the dead chick embryo were collected during day 4 to 9,dyed by Lugols Iodine and by Chlamydia Immunofluorescence Assay. In order to discriminate Chlamydia psittaci from Chlamyida trachomatis,the activity of isolated pathogen was inhibited by infusing Penicilln and sodium sulfadiazine.The isolated pathogen was injected into broilers of 15 day,observering the clinical pathology. Results The serological response was seen after the clinical signs, and the positive rate varied from 10%-30%.The activity of pathogen was demonstrated positive in fluorochrome.The same pathological change could be replicated by injecting the isolated pathogen. Conclusion The isolated pathogen may be an Chlamydia psittaci, whose conbined infection with E.Coli can be responsible for the severe respiratory disease with high mortality in broilers.