凡纳滨对虾3种主要病毒和虾肝肠胞虫在辽宁地区的流行情况分析

为解决近年来辽宁地区凡纳滨对虾Litopenaeus vannamei病害频发的问题,于2015年8月从辽宁省盘锦、营口地区26个发病的凡纳滨对虾养殖池塘中随机采集病虾样本,采用聚合酶链式反应(Polymerase Chain Reaction,PCR)检测对虾传染性皮下及造血组织坏死病毒(IHHNV)、对虾白斑综合征病毒(WSSV)和对虾桃拉综合征病毒(TSV),并用环介导等温扩增(Loop-Mediated Isothermal Amplication,LAMP)技术检测虾肝肠胞虫Enterocytozoon hepatopenaei(EHP)的感染情况。结果表明:IHHNV和EHP的检出率较高,分别为65.4%和34.6%,WSSV和TSV的检出率分别为19.2%和7.7%;EHP的检出率与对虾体型大小密切相关,在小虾样本中检出的阳性率高达100%,而大虾样本中均未检出;26份对虾样本中有7份样本同时携带EHP和IHHNV。研究表明,IHHNV和EHP是2015年8月辽宁地区凡纳滨对虾的主要流行病原,发病率可能与对虾生长缓慢、个体大小差异明显相关。

Epidemiological investigation of three major viruses and Enterocytozoon hepatopenaei(EHP) in Pacific white leg shrimp Litopenaeus vannamei in Liaoning Province

White spot syndrome virus (WSSV), infectious hypodermal and hematopoietic necrosis virus (IHHNV) and Taura syndrome virus (TSV) were detected by nested-PCR and RT-PCR and Enterocytozoon hepatopenaei (EHP)was detected by LAMP (Loop-mediated Isothermal Amplication) kit in diseased Pacific white leg shrimp Litopenaeus vannamei collected from 26 shrimp culture ponds in Yingkou and Panjin, Liaoning Province in August 2015. The results showed that the IHHNV had incidences of 65. 4% with positive rates of 19. 2% and EHP had in-cidences of 34. 6% . While the TSV showed positive rates of 7. 7% . EHP positive was found in all the small shrimp samples and seven diseased shrimp samples showed co-infection of IHHNV and EHP. There was higher positive rate in large-sized shrimp samples (100% ) than in small-sized shrimp samples (0% ). The findings indicated that IHHNV and EHP were major pathogens in Pacific white leg shrimp in Liaoning Province in August 2015.