花鲈感染简单异尖线虫及扫描电镜观察

目的简单异尖线虫(Anisakis simplex)是一类寄生于海水鱼类及哺乳类动物,可引起人类异尖线虫病(anisaki-osis)的食源性人兽共患寄生虫。作者从浙江宁波患病花鲈(Latealabrax japonicus)体内检出简单异尖线虫,检出率为100%(11/11)。患病鲈鱼体表无异常症状,解剖鱼体在肝脏、胃壁、肠壁、肠系膜等部位均有简单异尖线虫寄生,线虫盘成螺旋状包于包囊内,病鱼感染线虫强度为20～30条/尾。感染严重病鱼出现胃穿孔、胃壁出血、肝脏具白色结节等病症。光学显微镜观察线虫虫体为长圆筒形,两端较细,肌质食道,腺体的胃位于食管后面,黑色不透明,和肠连接处有一斜的分界线。扫描电镜观察虫体体表具致密环纹,前端钝圆,具1个钻齿和4个钝角状乳突,排泄口位于腹侧两个乳突之间,尾部短而圆,末端具一明显尾突。

Observation on the morphology of Anisakis simplex pathogenic to sea perch by scanning electron microscopy

Anisakis simplex is a zoonotic parasite infecting sea fishes and mammals and also a causative agent of a human disease called anisakiosis. We had found larvae of A. simplex from the diseased sea perch Lateolabrax japonicus from fish farm in Zhejiang province, in which 20--30 larvae of A. simplex were isolated per fish with a detection rate of 100%（11/11）. They were mainly located in liver, stomach and intestinal walls and mesentery of the sampled sea perch. In the severely infected fishes, gastric perforation, hemorrhage on the gastric wall and the presence of white nodules in liver. As demonstrated on the observation by light and electron microscopy, the adult worms appeared to be long and round cylinder-shaped and smaller at both end of the worm body. Their front end was blunt with one prominent boring tooth and 4 projections, while their tail was short and round with distinct mucron, cuticle with transverse striations and irregular wrinkles near the tail.