实验室条件下广州管圆线虫生活史的建立

Construction of the life cycle of Angiostrongylus cantonensis in laboratory

目的人工建立一套规范的实验室条件下的广州管圆线虫生活史过程,探索广州管圆线虫人工繁殖的技术和方法,为深入研究广州管圆线虫病,提供充足、有效的试验材料。方法从广州管圆线虫疫区采集广州管圆线虫中间宿主褐云玛瑙螺,解剖分离三期幼虫,经口感染SD大鼠。6周后采集镜检鼠粪,贝尔曼漏斗法分离粪便内一期幼虫感染实验室养殖的二代褐云玛瑙螺白化种白玉蜗牛25只,3周后解剖螺镜检三期幼虫并计数。将阳性螺直接喂食饥饿SD大鼠10只,感染2周后检测血清,6周后镜检鼠粪,并分别于3、5、8周时解剖大鼠观察虫体。结果感染3周后解剖白玉蜗牛镜检可见三期幼虫,大鼠感染2周后检测血清特异性抗体阳性,6周后镜检鼠粪可见一期幼虫,3周后脑部解剖可见四期幼虫,5周、8周后心肺部解剖可见成虫与虫卵。结论利用SD大鼠与白玉蜗牛为宿主在实验室条件下成功建立广州管圆线虫生活史。

Objective To construct the life cycle ofAngiostrongylus cantonensis （A.cantonensis） in laboratory condition. Method SD rats were infected orally with the third-stage larvae of A.cantonensis collected from Jiangmen, Guangdong province. Six weeks after infection, the first-stage larvae were isolated from fresh feces of the rats by using Baermann funnel to infect 25 second-generation white jade snails raised in laboratory at the daily dose of 300 000 for 3 consecutive days. Three weeks later, the snails were dissected for counting the third-staged larvae of A.cantonensis, and those positive for A. cantonensis infection were fed directly to 10 fasting rats. The serum samples of the rats were then collected 2 weeks later for examination of specific antibodies using ELISA. The feces of the infected rats were examined microscopically after 6 weeks, and the brain, ＇ heart and lungs of the infected rats were dissected to observe the larvae at 3, 5, and 8 weeks, respectively. Results The 3-stage larvae of A.cantonensis were found in the second-generation snails 3 weeks after infection. The positivity rate of serum specific antibodies was 100% in the 10 rots 2 weeks after feeding of the infected snails. The 1-stage larvae were detected in the feces of the rots 6 weeks after infection, and the fourth-stage larvae were found in the brain of the rots at 3 weeks, while adult worm and eggs were found in the heart and lungs of the infected rots at 5 and 8 weeks. Conclusion The entire life cycle of A.cantonensis can be established in laboratory within 9 weeks using the white jade snail and SD rats as the hosts.