对虾白斑综合症研究进展

综合对虾白斑综合症的研究进展,介绍了该病的病理学、传播途径、症状、检测方法及防治对策,为对虾白斑综合症的进一步研究提供参考.     

对虾白斑综合症病毒的分子生物学研究进展

对虾白斑综合症病毒(wkite spot syndrome virus,WSSV)又称对虾白斑杆状病毒(white spot bacilliform virus WSBV),是对全球对虾养殖业危害最大的病原之一。该病毒分子量较大、结构特异,是已知动物病毒中最大的病毒。自1992年以来,各国学者对WSSV进行研究。由于他们研究的方法及研究的侧重点不同,对该病毒命名各异。陈秀男(1993)称之为白斑综合症杆状病毒(WSBV);荷兰Wongteerasupaya(1995)称其为系统外胚层和中胚层杆状病毒(SEMBV);     

对虾白斑综合症的研究综述

对虾白斑综合症是由对虾白斑综合症病毒（white spot syndrome virus WSSV)引发的暴发性流行病，典型症状是病虾甲壳内侧出现0.5-2mm大小不等的白色斑点，此病病程短，死亡率高。白斑综合症病毒（WSSV）的形态结构与杆状病毒相似，杆状病毒分子分布于患病组织细胞核内，WSSV不仅水平传播，还存在垂直传播的可能性，到目前为上，诊断技术己较为进步，但尚无有效手段控制该病的发生。今后的研究重点在防治上。     

白斑综合症病毒在日本囊对虾精养池塘中的动态变化

用实时荧光定量PCR技术检测了高密度精养池塘中日本囊对虾体内及浮游动物白斑综合症病毒携带量的动态变化,检测结果显示,两口池塘的日本囊对虾苗种均携带白斑综合症病毒,达2.43×10~5~9.42×10~5 IU/mg;浮游动物也携带微量白斑综合症病毒,达6.78×10~2~8.02×10~2 IU/mg。在整个养殖过程中,日本囊对虾多个组织均携带白斑综合症病毒,平均病毒量为鳃肌肉肝胰腺胃;各组织病毒携带量的变化趋势不一致,肌肉、肝胰腺、胃等呈现明显的先降后升趋势,最低降至1.78×10~3 IU/mg,鳃白斑综合症病毒携带量的下降幅度较小,最低为7.29×10~4 IU/mg。浮游动物的病毒量在白斑综合症爆发前波动不明显,发病时急剧升高。综合认为,苗种携带是白斑综合症病毒的主要来源;当养殖进入中后期,底质变差、水温降至病毒适宜复制的温度时,易爆发白斑综合症。     

对虾皮下及造血组织坏死杆状病毒单克隆抗体的ELISA快速检测

对虾病毒性暴发病对我国对虾养殖业的危害十分严重,其病原为皮下及造血组织坏死杆状病毒(ｈｙｐｏｄｅｒｍａｌａｎｄｈｅｍａｔｏｐｏｉｅｔｉｃｎｅｃｒｏｓｉｓｂａｃｕｌｏｖｉｒｕｓＨＨＮＢＶ)[1]或称为对虾白斑综合症病毒(ｗｈｉｔｅｓｐｏｔｓｙｎｄｒｏｍｅｂａ?..     

凡纳滨对虾感染白斑综合症病毒后的新症状

2007年6-7月,辽宁营口地区凡纳滨对虾养殖场陆续出现死虾现象,通过组织病理观察和PcR检测,确定为白斑综合症.患病初期,对虾并未表现出典型白斑、甲壳易剥离等症状,而在鳃区头胸甲内侧滋生一种囊状胶状物,导致头胸甲内侧肿胀,病理观察发现该滋生物为对虾感染白斑综合症病毒后,皮下组织"胶质化"的结果,同时胃和皮下组织的结缔组织中有大量的典型性病变核;细菌分离结果显示,伴随着弧菌和假单胞菌的混合感染.     

对虾白斑综合症（WSS）的分子流行病学研究进展

本文主要依据1993年以来关于白斑综合症(WSS)的研究结果,对白斑综合症的致病因子与暴露、生物标志与生物学效应、易感性、预防策略进行综合评述,以期为有效控制WSS疫情、重振对虾养殖业提供参考。     

南美白对虾亲虾良种选育技术

我国南美白对虾养殖业发展迅猛，其亲虾选育和种苗繁育发挥了关键作用。但是由于缺乏无特定病原（SPF）和抗特定病原（SPR）的南美白对虾健康亲本选育，以及病害检测手段落后，遗传育种工作滞后，导致亲本选择不严，近亲变配现象严重，造成对虾的白斑综合症病毒（WSSV）、桃拉病毒（TSV）和传染性皮下及造血组织坏死病毒（IHHNV）在南美白对虾养殖过程中普遍流行；     

对虾白斑综合症病毒暴发流行与传播途径、气候和水体理化因子的关系及其控制措施

白斑综合症病毒（whitespotsyndromevirus,WSSV）,又称白斑杆状病毒（whitespotbaculovirus）、皮下与造血组织坏死杆状病毒（hepodermalandhematopoieticnecrusisbaculovirus）、日本对虾棒状病毒（Rodshapevirusofpenaeusjaponicus）、白斑综合症杆状病毒（whitespotsyndromebaculovirus）、系统性外胚层和中胚层杆状病毒（systemicectodermalandmesodermalbaculovires）等。WSSV为全球养殖对虾危害性最大的病毒,每年因WSSV全球养殖对虾产量减少一半,损失几百亿元人民币。近年,随着对WSSV认识的逐渐深入,对虾养殖技术有所提…     

南方气候多变南美白对虾大面积暴发病害

今年南方地区因气候异常多变，对虾发病率与死亡率大幅度上升。5月份广西全区各地南美白对虾长时间出现局部性流行病，钦州东场、防城企沙等地大面积暴发红体、白斑综合症，部分地区对虾还出现黄鳃、黄头症状。     

Prevalence of Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) and White Spot Syndrome Virus (WSSV) in Litopenaeus vannamei in the Pacific Ocean off the Coast of Panama

Abstract.— In March 2000, 104 wild caught Litopenaeus wannamei broodstock, captured off the Pacific coast of Panama, were screened for the following penaeid viruses: infectious hypodermal and hematopoietic necrosis virus (IHHNV) and white spot syndrome virus (WSSV). The purpose of this study was to determine the prevalence of IHHNV and WSSV in wild shrimp in this area of the Western Hemisphere and to acquire specific pathogen free (SPF) L. vannamei for inclusion into the Oceanic Institute's genetic breeding program. The prevalence of the viruses was determined using the dot blot hybridization format, which is a commercially available molecular method for detecting these viruses. Dot blot hybridization assays can be used as an initial screening method to detect moderately to highly infected shrimp. The results from the dot blot assays indicated the prevalence of IHHNV in 28% and WSSV in 2% of the 104 hemolyrnph samples tested. Results from this study were used to establish the initial candidate SPF status of the animals that were assessed and to determine the prevalence of two serious pathogens of penaeid shrimp captured from the wild of the Pacific Ocean in the Central American region off the coast of Panama.     

传染性皮下及造血组织坏死病毒致病性研究进展

传染性皮下及造血组织坏死病毒(IHHNV)是一种分布较广、危害较大的对虾病毒,已被世界动物卫生组织(OIE)列为须向其申报的甲壳类重要疫病病原。IHHNV在我国已形成了一定的流行趋势,目前仍是严重危害我国养殖虾类的重要病毒。本文从IHHNV的流行地区及危害、宿主、致病类型、对宿主不同年龄阶段的致病性差异、与白斑综合征病毒(WSSV)的干扰作用、感染机制和致病机理方面,综述了与IHHNV致病性相关的研究进展,以期为进一步深入研究IHHNV防控提供参考资料。     

A single-step multiplex PCR for simultaneous detection of white spot syndrome virus and infectious hypodermal and haematopoietic necrosis virus in penaeid shrimp

White spot syndrome virus (WSSV) and infectious hypodermal and haematopoietic necrosis virus (IHHNV) are the major viral pathogens of penaeid shrimp worldwide (Lightner & Redman 1998). Litopenaeus vannamei was introduced into China from the Americas, and quickly became widely cultured. Following its introduction, both IHHNV and WSSV have become important pathogens of cultured penaeid shrimp and have had a huge impact on the culture industry in China in recent years.     

Development of monoclonal antibodies against VP28 of WSSV and its application to detect WSSV using immunocomb

White spot disease (WSD) is an important viral disease of penaeid shrimp caused by white spot syndrome virus (WSSV). WSSV isolated from WSD outbreaks in commercial shrimp (Penaeus monodon) farms in India were propagated in the laboratory in healthy shrimp. The virus was purified from the infected tissues by sucrose gradient centrifugation. The VP28 was electroeluted from SDS-PAGE gels and was used to immunize Balb/c mice to produce hybridomas secreting monoclonal antibodies (MAb) against WSSV. A total of five hybridoma clones secreting MAbs to VP28 were produced. The MAbs were of the isotypes IgG1, IgG2b and IgM. The MAbs reacted with VP28 of WSSV and not with any other viral or shrimp protein in western blot. The MAbs were used to develop dot immunoblot assay using an immunocomb to detect WSSV from field samples. The test developed had an analytical sensitivity of 625 pg and a diagnostic sensitivity of 100% compared to single step polymerase chain reaction (PCR). The test can be used as an alternate for first step PCR to detect WSSV from field samples.     

Anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate against white spot syndrome virus in freshwater crab (Paratelphusa hydrodromous)

Shrimp farming industries are subjected to severe economic loss due to a disease called white spot syndrome, a viral disease caused by white spot syndrome virus (WSSV) in penaeid shrimp. Numerous active compounds in the market possess anti-viral activity against the white spot syndrome virus, yet the issue remains unsolved. The present study was carried out to determine the anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate (C₁₃H₁₅N₂O₂Cl) against WSSV. The anti-viral activity of the synthetic compound was determined in freshwater crabs. Crabs were divided into three different experimental groups: healthy control groups (N.C.) received NTE buffer, positive control group (P.C.) crabs received WSSV, and treatment group crabs received WSSV along with synthetic weight compound. Experimental groups were observed for 30 days post-infection. Three different organs (gills, muscles, and head soft tissue (HST)) were dissected from all three groups and analyzed using molecular-based techniques, including polymerase chain reaction (PCR), Western blot, and histopathology. Clinical signs of WSSV were observed in the positive and N.C. groups; however, the treatment group showed a 100% survival rate. Confirmation was done using PCR, Western blot, and histopathology. These results demonstrated that the given synthetic compound has significant anti-viral activity against WSSV.

     

Recent insights into host–pathogen interaction in white spot syndrome virus infected penaeid shrimp

Viral disease outbreaks are a major concern impeding the development of the shrimp aquaculture industry. The viral disease due to white spot syndrome virus (WSSV) observed in early 1990s still continues unabated affecting the shrimp farms and cause huge economic loss to the shrimp aquaculture industry. In the absence of effective therapeutics to control WSSV, it is important to understand viral pathogenesis and shrimp response to WSSV at the molecular level. Identification and molecular characterization of WSSV proteins and receptors may facilitate in designing and development of novel therapeutics and antiviral drugs that may inhibit viral replication. Investigations into host–pathogen interactions might give new insights to viral infectivity, tissue tropism and defence mechanism elicited in response to WSSV infection. However, due to the limited information on WSSV gene function and host immune response, the signalling pathways which are associated in shrimp pathogen interaction have also not been elucidated completely. In the present review, the focus is on those shrimp proteins and receptors that are potentially involved in virus infection or in the defence mechanism against WSSV. In addition, the major signalling pathways involved in the innate immune response and the role of apoptosis in host–pathogen interaction is discussed.     

The molecular detection of Taura syndrome virus emerging with White spot syndrome virus in penaeid shrimps of Thailand

This study is to investigate the outbreak of the Taura syndrome (TS) in penaeid shrimps of Thailand. Following the outbreak in 2003, the Taura syndrome virus (TSV) was detected in two closely related penaeids; the Pacific white shrimp, Penaeus vannamei, and the black tiger prawn, Penaeus monodon. Multiple viral infections were detected, we found that the TSV-infected P. vannamei also presented evidence of the White spot syndrome virus (WSSV) as evidenced by histological examination and molecular diagnostic methods. Infections of TSV and WSSV were investigated over a period of ten months between October 2003 and July 2004. TSV infection in shrimps was diagnosed by RT-PCR using the OIE recommended 9195/9992 primers. Positive shrimp gave the expected amplicon of 231 bp. We also amplified and sequenced a fragment of the vp1 gene (354 bp). The pairwise comparisons of vp1 revealed that Thai TSV was phylogenetically related to the Taiwanese strains (98.3% identity).     

Testing of a pond‐side molecular diagnostic tool for the detection of white spot syndrome virus in shrimp aquaculture

White spot disease in penaeid shrimp is caused by the white spot syndrome virus (WSSV). It is the most economically important disease of farmed warm‐water shrimp, causing extensive economic losses estimated from $8 to $15 billion since its emergence in the 1990s. Early diagnosis of disease is critical in the management of outbreaks and to avoid crop losses. Diagnosis of white spot disease is generally carried out in centralized laboratory settings using molecular biology approaches. However, this mode of testing can be expensive and time consuming, requiring laboratory equipment, highly trained laboratory personnel, dedicated laboratory space, and long‐distance transportation of samples from field to lab. In‐field diagnostics are gaining credence as tools for rapid and early animal disease detection, allowing diagnosticians and farmers to potentially manage disease outbreaks from the pond side. In the present study, we describe the development and application of a new in‐field point‐of‐need diagnostic test and platform for the diagnosis of WSSV in remote settings (shrimp farms). We report its performance in laboratory and field settings and compare it with current gold‐standard diagnostic approaches. We discuss the potential benefits (and barriers to uptake) of applying such testing in the global shrimp farming sector.