大链壶菌感染对致倦库蚊幼虫体内元素的影响

目的　了解大链壶菌感染对致倦库蚊幼虫体内元素的影响 ,从无机化学角度探讨大链壶菌 (L agenidiumgiganteum)灭蚊的可能机制。　方法　采用原子发射光谱仪 ,测定正常蚊幼虫 (对照组 )与感染大链壶菌后不同时期蚊幼虫 (实验组 )组织与生命活动有关的 18种元素含量的变化。　结果　感染 0 h(即加入大链壶菌块后 30～ 4 8h,幼虫体表布有黑化点 ,为初始感染 ) ,实验组的 Ca、Cu含量明显低于对照组 ,Co、Cd含量明显高于对照组。感染 2 4 h,实验组和对照组间有 16种元素含量有明显差异 ,其中 Ca、Mg、Na、P、Fe、Zn、Cu、Mn、Cr含量明显低于对照组 ,K、Mo、Co、Ni、Al、Cd、Pb含量明显高于对照组。感染 4 8h,除 Sr外 ,17种元素含量与对照组间均有明显差异。　结论　大链壶菌感染蚊幼虫后 ,使多种维持正常生命活动的元素呈降低趋势 ,而一些重金属等有害元素在体内储积。这可能是影响蚊幼虫正常生命活动以致死亡的重要原因。

Changes of Elements in Culex quinquefasciatus Larvae after Infected by Lagenidium giganteum (Oomycetes:lagenidiales)

Objective To analyze the quantitative change of 18 elements in Culex quinquefasciatus Larvae infected by Lagenidium giganteum (Oomycetes:lagenidiales), and to explore possible mechanism of mosquito-killing by the fungus. Methods. Elements in the mosquito larvae at different developmental stages from infected and non-infected (control) groups were detected with automatic bioassay machine. Results . At the early stage of infection, content of Ca and Cu in the infected group was markedly lower while the content of Co and Cd were higher than the control. In 24 hrs after infection, the content of Ca, Mg, Na, P, Fe, Zn, Cu, Mn and Cr was significantly lower while that of K, Mo, Co, Ni, Al, Cd and Pb were higher than those in non-infected larvae. No marked difference was found for the content of Sr and B between the two groups. In 48 hrs after infection, considerable difference was found in 17 elements between infected and non-infected larvae, with only one exception of Sr. Conclusion . Many elements which play an important role in maintaining the vitality of the mosquito larvae decreased and some of the heavy metal elements accumulated after the infection of Lagenidium giganteum. This might be a part of the killing mechanism to Culex quinquefasciatus larvae.