广州管圆线虫感染大理州福寿螺模型的构建及探讨

Construction and discussion of an infection model of Dali Ampullaria gigas by Angiostrongylus cantonensis

目的构建广州管圆线虫人工感染大理州福寿螺实验动物模型，观察并探讨感染后福寿螺的生长变化和感染效果，为本地区深入研究广州管圆线虫病提供充足的试验材料。方法用福寿螺体内的广州管圆线虫（第三期幼虫）感染昆明小鼠，6周后用含有广州管圆线虫一期幼虫的新鲜鼠粪感染大理本地繁殖的福寿螺，将福寿螺随机分为A、B、C、D组，每组40只，各感染一期幼虫0条、800条、700条、600条／只，相同感染数量和相同时间内重复感染，连续7d。感染后36～40d，使用酶消化法查找三期幼虫，观察螺的死亡率、感染率、感染度及各组三期幼虫感染昆明小鼠的感染性。结果A、B、C、D组死亡率依次为0、65％、60％、25％。A组无三期幼虫的感染，B、C、D组存活螺的感染率均达到100％，感染度D组明显高于B、C组（P〈0．05），各组分离的三期幼虫能成功感染昆明小鼠，感染率为100％。结论广州管圆线虫能成功感染大理州福寿螺，并能成功用此福寿螺体内的三期幼虫感染昆明小鼠。

Objective To set up an artificial infection model of Dali Ampullaria gigas by Angiostrongy- lus cantonensis, observe the growth after infection and the effectiveness of the infection, thus to provide adequate materials for further research on angiostrongyliasis cantonensis in Dali. Methods Kunming mice were infected with Angiostrongylus cantonensis selected from positive Ampullaria gigas. After 6 weeks of infection, the first stage larvae of Angiostrongylus cantonensis in fresh mice feces were collected to infect Ampullaria gigas of Dali. Ampu[laria gigas were randomly divided into 4 groups, namely A, B, C, D （40 per group）. Amp- ullaria gigas in group A, B, C, D were infected with 0, 800, 700, 600 first stage larvae of Angiostrongylus cantonensis respectively, keeping infecting for 7 days. On 36 - 40 d after infection the third stage larvae were collected by pepsin digestion to determine the death rate, infection rate, infectiosity of Ampullaria gigas, and infectivity of the third stage larvae to infect Kunraing mice. Results The mortality of Ampullaria glgas in group A, B, C, D were 0, 65% , 60% , 25% respectively. The infection rate in group A was 0 while that in group B, C, D was 100%. Meanwhile, the infectiosity in group D was higher than that in group B and C（P 〈 0.05 ）. The third stage larvae separated from each group could infect Kunming mice successfully with the infection rates of 100%. Conclusion Angiostrongylus eantonensis could successfully infect Ampullaria gigas from Dali. The third stage larvae from Dali Ampullaria gigas could infect Kunming mice.