不同温度对广州管圆线虫感染期幼虫的杀灭作用

Killing Effects of Different Temperature on Infective Larvae of Angiostrongylus cantonensis

目的探究广州管圆线虫感染期幼虫(第Ⅲ期幼虫)在不同温度不同时间下的生存及死亡情况(死亡率)。方法采用人工消化法,从自然感染的褐云玛瑙螺中提取广州管圆线虫感染期幼虫,将其放入不同温度(35～90℃)的热水中,分别作用不同时间(1～20min),取出置解剖镜下观察虫体的变化情况。结果在1～20min内,45℃以下温度对感染期幼虫不具有杀灭作用,死亡率为0;50～55℃温度对感染期幼虫有轻度的杀灭作用,死亡率为12.00%～97.33%;60～65℃温度对感染期幼虫有一定强度的杀灭作用,死亡率为57.39%～100.00%;70～75℃温度对感染期幼虫有很强的杀灭作用,死亡率为97.22%～100.00%;在80℃以上温度时感染期幼虫迅速死亡,死亡率为100.00%。结论45℃以下温度,20min内对广州管圆线虫感染期幼虫没有杀灭作用;50～75℃温度,1～20min,对大多数广州管圆线虫感染期幼虫具有杀灭作用,温度越高,时间越长,杀灭作用越强;80℃以上温度,1～20min,对广州管圆线虫感染期幼虫具有完全杀灭作用。

Objective To explore the survival and death （mortality） rate of infective larvae （No. Ⅲ larvae） of Angiostrongylus cantonensis under different temperatures and within different time periods. Methods Using artificial digestion method ,infective larvae of A ngiostrongylus cantonensis were collected from naturally infected Aehatina fulica and were submerged into hot water at different temperatures （35-90℃） for different periods of time （1-20 min）. Then the worms were removed from water to observe the anatomical changes under microscope. Results Blow 45℃ and between 1-20 min period, no killing effect was found and the mortality rate was 0; Between 50-55℃ a weak killing effect on the infective larvae was recorded, with the mortality rate 12.00%-97.33%; when temperature rose to 60- 65℃ ,it showed a noticeable killing effect on the infective larvae with the mortality rate ranging from 57.39% to 100.00%. At 70-75℃ of temperature, killing effect was very strong, with the mortality rate at 97.22%-100.00%. And above 80℃ ,the infective larvae died quickly,the mortality rate was 100.00% .Conclusion Below 45℃ temperature, there is no killing effect for infective larvae of A ngiostrongylus cantonensis in 20 min.There is a killing effect for the majority of infective larvae of Angiostrongylus cantonensis under 50~75℃and within 1-20 min.The higher the temperature, the longer in the water, the stronger is the killing effect to infeetive larvae. Above 80℃, in 1~20 min, infective larvae of Angiostrongylus cantonensis will be killed completely.