珍珠鸡和雉鸡贝氏隐孢子虫实验感染研究

 采用鸭源贝氏隐孢子虫卵囊经口感染珍珠鸡和雉鸡，感染后的4～30天和4～25天，分别在珍珠鸡和雉鸡的粪便中检出卵囊。贝氏隐孢子虫在珍珠鸡和雉鸡的喉头、气管、支气管、法氏囊和泄殖腔的粘膜上皮发育。珍珠鸡感染后出现明显的呼吸道症状，剖检可见眶下窦肿大、气管和法氏囊水肿、表面有大量粘液、肺暗红、气囊增厚呈云雾状外观。组织学检查可见气管和法氏囊上皮细胞增生、肿胀和脱落以及炎性细胞浸润。感染后33天，珍珠鸡体重明显低于未感染对照组。与珍珠鸡相比，雉鸡感染后只出现轻微呼吸道症状，大体及组织病变均较轻，且体重与对照组无显著差异。实验表明，珍珠鸡和雉鸡是贝氏隐孢子虫的新宿主。

EXPERIMENTAL INFECTIONS IN GUINEA FOWLS AND PHEASANTS WITH CRYPTOSPORIDIUM BAILEYI

Guinea fowls and pheasants that were inoculated orally with oocysts of Cryptosporidium baileyi isolated from ducks became infected, and shed oocysts in their feces on 4 to 30 and 4 to 25 days after inoculation (DAI) respectively. Developmental stages of C, baileyi were observed on the epithelium of the larynx, trachea, bronchi, bursa of Fabricius and cloaca of the two kinds of birds. Inoculated guinea fowls developed clinical signs of respiratory disease and had gross lesions, including swollen infraorbital sinus, hydropsy of the trachea and bursa of Fabricius, excessive mucoid exudate in the lumen of trachea and bursa of Fabricius, dark-red lungs and cloudy sacs at necropsy. Histologic lesions in the trachea and bursa of Fabricius were epithelial hyperplasia, epithelial cell swelling and exfoliation, and infiltration of inflammative cells. Weight gains for inoculated guinea fowls were lower (P<0.01) than control form 1 to 33 DAI. In contrast with guinea fowls, mild clinical signs of respiratory disease, and slight gross and histologic lesions were observed in the inoculated pheasants. Weight gains for the inoculated pheasants from 1 to 33 DAI were not significantly different from that of control. Our studies indicated that the guinea fowl and pheasant were the new hosts of C. baileyi.