鸡突变膝螨的形态和离体存活力及致病性研究

Morphology,survival vitality in vitro and pathogenicity of Knemidocoptes mutans from chicken

运用光学显微镜与扫描电子显微镜相结合的方法观察了突变膝螨的外部形态。测定了在不同的温度和PH条件下，离体突变膝螨的存活时间，并对病鸡的患病部位进行了组织病理学观察。结果显示，突变膝螨在其生活史过程中有卵、幼虫、若虫和成虫4个发育时期，其中雌螨有2个若虫期，雄螨有1个若虫期，并且都有各自的形态特征。离体突变膝螨在4～25℃可以存活4～9d；在pH为4、5、7、8的环境条件下，离体突变膝螨的最大存活时间依次为120、132、120和96h。病理组织学观察显示，突变膝螨的寄生部位为角质层的外层、中层和内层，在严重感染的情况下一些虫体可通过角质层侵入表皮深层，到达基层附近，并引发真皮致密层，甚至疏松层发生严重的炎症反应。

Morphology of Knemidocoptes mutans （K. mutans） in vitro from chicken was observed by optical microscope and scanning electronic microscope. The maximum survival time of K. mutans in vitro was examined at different temperatures and pH values,and pathological changes of the K. mutans from infected chickens were observed,too. The results showed that the life cycle of K. rnutans had four developmental stages of egg,larva, nymph and adult. The female had two nymphal stages, but male had only one. Their morphologies were different. K. mutans in vitro could survive for 4-9 d at 4--25℃. The maximum survival time of K. mutans in vitro was 120 h at pH 4,132 h at pH 5,96 h at pH7 and 96 h at pH8 respectively. Histopathological changes showed that K. mutans parasitised in corneous layer. In serious infection, some mites could penetrate the deep layer of cuticle and even resulted in severe dermatitis in stratum spongiosum and stratum compactum of dermis.