广州管圆线虫对不同宿主感染性的比较研究

目的比较广州管圆线虫在褐云玛瑙螺和福寿螺螺体内的发育情况及对BALB／c小鼠和昆明鼠的毒力，寻找适宜的实验室易感宿主。方法连续7d分别用感染大鼠的粪便喂食福寿螺和褐云玛瑙螺．1个月后解剖感染螺，观察螺体内广州管圆线虫幼虫的发育情况及虫数；从褐云玛瑙螺和福寿螺分离广州管圆线虫Ⅲ期幼虫（L3）分别感染昆明鼠；而感染BALB／c小鼠的Ⅲ期幼虫来自于褐云玛瑙螺。通过观察感染小鼠的死亡率、体重变化、mmp-9活性、脑组织的病理变化、脑内虫体数及脑脊液总蛋白含量等指标评价不同来源幼虫对不同小鼠的致病力。结果广州管圆线虫在褐云玛瑙螺及福寿螺中的发育无显著性差异．但褐云玛瑙螺感染的幼虫数量高于福寿螺。BALB／c小鼠感染广州管圆线虫后其死亡率、mmp-9活性、脑内虫体数及脑脊液总蛋白含量等明显高于昆明小鼠，其体重减轻、病理变化也更明显。用不同螺来源的Ⅲ期幼虫感染的小鼠其mmp-9活性、脑内虫体数、脑脊液总蛋白含量、体重减轻及脑组织病变程度均无显著差异。结论BALB／c小鼠、褐云玛瑙螺与福寿螺对广州管圆线虫易感，BALB／c小鼠是较好的实验室易感宿主，褐云玛瑙螺与福寿螺来源的广州管圆线虫Ⅲ期幼虫对小鼠的毒力无差异，从环保角度考虑褐云玛瑙螺更适合于实验室应用。

Angiostrongylus cantonensis Infection in Different Host Snails and Pathogenicity in Different Mouse Strains

Objective Compare the pathogenicity ofAngiostrongylus cantonensis between BALB/c mice and KM mice and infection of Ampullarum crossean and wild giant African snails, and search for a suitable infective host for research in laboratory. Method Ampullarum crossean and wild giant African snails were fed by the feces containing the eggs of A ngiostrongylus cantonensis collected from infected mice. After one month of challenge, the snails were examined and the larvae were collected. Each KM mouse was infected with 30 larvae（L3）of Angiostrongylus cantonensis collected from wild giant African snails or from Ampullarum crossean; BALB/c mice were infected with L3 collected from wild giant African snails. Rate of death, change of weight, activity of mmp-9, worm recovery, histopathological score of meningitis, total protein, and leukocyte counts were used for the comparison of the virulence of the larva collected from the different snails. Result The development of Angiostrongylus cantonensis in Ampullarum crossean and wild giant African snails showed no difference. The rate of death, change of weight, activity of mmp-9, worm recovery, histopathological score of meningitis, total protein, and leukocyte counts in infected BALB/c mice were higher than those of infected KM mice. The change of weight, activity of romp-9, worm recovery, histopathological score of meningitis, and total protein in mice infected with larvae collected from Ampullarum crossean and wild giant African snails also showed no difference. Conclusion The virulence ofAngiostrongylus cantonensis collected from AmpuUarum crossean and wild giant African snails showed no difference. BALB/c mouse, Ampullarum crossean and wild giant African snails were suitable hosts for A ngiostrongylus cantonensis, but wild giant African snails were better than A mpullarum crossean when the protection of environment was considered.