扇贝养殖海区浮游生物及大型海藻携带AVNV病毒的检测分析

Identification of AVNV carried by plankton and macroalgae along sea areas for culturing Chlamys farreri by FQ-PCR

为了解扇贝养殖海区浮游生物及大型海藻与急性病毒性坏死症病毒(AVNV)流行传播的关系,本研究于2008年和2009年从青岛沙子口和荣成桑沟湾2个养殖海区采集水样,离心收集浮游生物并随机采集大型海藻,采用荧光定量PCR(FQ-PCR)技术对这些样品携带AVNV情况进行检测。结果显示,沙子口海区8月份的浮游生物样品中检测到AVNV,每升海水中浮游生物携带的病毒数量为6.92×105拷贝;桑沟湾海区4月份的浮游生物样品也检测到AVNV,每升海水中浮游生物携带的病毒数量为1.26×103拷贝。从青岛沙子口海区随机采集的10种大型海藻中有7种[包括孔石莼(Uiva pertusa)、浒苔(Enteromorpha prolifera)、细毛石花菜(Gelidium crinale)、缘管浒苔(E.Linza)、海膜(Halymenia floresia)、扁江蓠(Gracilaria textorii)、刚毛藻(Cladophora)]检测到病毒,带毒样品占到检测样品总数的55.56%,其中在12份孔石莼样品中,11份样品检测到病毒,携带病毒数量最高为7.68×104/0.1(g2009年8月25日)。从荣成桑沟湾海区采集的14种大型海藻样品中有3种(包括孔石莼、海膜和马尾藻)检测到病毒,带毒样品占到检测样品总数的20.83%,其中2009年7月采集的孔石莼样品携带病毒数量最高,为3.06×103/0.1g。这一结果说明海区浮游生物及部分大型海藻均可携带AVNV,而摄食携带病毒的浮游生物可能是扇贝感染发病的原因,有关大型海藻携带AVNV在该病原流行传播中的作用还有待进一步研究。

In order to illuminate the function of plankton and macroalgae on transmission of Acute Viral Necrobiotic Viru（sAVNV）,samples of macroalgae and plankton were collected randomly from sea areas along Shazikou of Qingdao and Sanggouwan of Rongcheng in 2008 and 2009.The AVNV carried by plankton and different species of macroalgae was identified by PCR and FQ-PCR technique.The results showed that the AVNV was detected from plankton collected along the sea areas for Chlamysfarreri culturing at Shazikou in August and at Sanggouwan in April by FQ-PCR,and the copy numbers of AVNV were 6.92×10^5 and 1.26×10^3 per liter of sea water,respectively.Twenty of 36 macroalgae samples collected along the sea areas of Shazikou in 14 months were AVNV positive,accounting for 55.56%of the total number.The positive samples included seven species which were Uivapertusa,Enteromorpha prolifera,Gelidium crinale,E.linza,Halymenia floresia,Gracilaria textorii and Cladophora.Five of 24 macroalgae samples collected along the sea area of Sanggouwan in nine months were AVNV positive,accounting for 20.83%of the total number.The positive samples belonged to three species including U.pertusa,H.floresia and Sargassum.U.pertusa was the main macroalgae carrying AVNV.Eleven of 12 U.pertusa samples collected along sea areas of Shazikou were AVNV positive,with the highest AVNV number being 7.68×10^4/0.1g in fresh sample collected on August 25,2009,while at that of Sanggouwan,three of fiveU.pertusa samples collected were AVNV positive,with the highest AVNV number being 3.06×10^3/0.1g in fresh sample collected in July,2009.The present results implied that plankton and some of macroalgaes could carry AVNV,and the scallops could be infected when they take plankton carrying virus as food.The role of macroalgae carrying AVNV in transmission of AVNV remains to be further studied.