马铃薯Y病毒HC-Pro、CI、NIb和CP基因介导的病毒抗性比较研究

 根据已克隆的马铃薯Y病毒坏死株系(PVY^N)的基因组序列设计引物,利用PCR扩增HC-Pro、CI、NIb和CP4个基因的3'端400bp cDNA区段,分别反向插入含有査尔酮合成酶基因(Chalcone synthase,CHS)内含子的双元载体pRCHS中,构建了含内含子的发夹结构RNA (intron splicing hpRNA,ihpRNA)表达载体pRCHS-HC-Pro、pRCHS-CI、pRCHS-NIb和pRCHS-CP。利用农杆菌介导法转化烟草品种NC89,获得了多种转基因植株。病毒抗性检测的结果显示:转pRCHS-HC-Pro、pRCHS-CI、pRCHS-NIb和pRCHS-CP的烟草中,抗性植株的比例分别为55.34%、73.69%、61.54%和84.21%。大分子RNA和siRNA的Northern blot分析表明,目的片段转录产物的积累量与转基因植株的抗病性呈负相关,转基因植株中可检测到siRNA,说明所获得的抗病性是RNA沉默介导的。     

陕西省猪伪狂犬病流行病学调查和WG株的分离鉴定

应用gE-EL ISA法对陕西省部分地区6个集约化猪场的187份猪血清进行了伪狂犬病毒(P seu-dorab ies v irus,PRV)野毒感染检测,并对疑似伪狂犬病发病仔猪的内脏及脑组织进行了病毒分离鉴定。结果显示,陕西省猪PRV野毒抗体平均阳性率为28.76%,最高为48.98%,最低为0;分离毒株可致PK-15细胞出现典型的圆缩、集聚,脱落等细胞病变,连续传代后,CPE出现的时间稳定在20 h左右;细胞培养物和病料混悬液接种家兔均出现典型奇痒症状,PCR反应扩增出PRV gE基因中长度为612 bp的特异性片段。表明本试验分离的病毒为PRV,并将其命名为PRV W G株。     

人工感染种鸭生殖系统中新城疫病毒的检测

本研究旨在探明鸭源新城疫病毒(NDV)通过人工感染后在种鸭生殖系统中分布。应用本实验室分离的一株经鸭胚传递的NDV SDFCH株,对42只无NDV感染的28周龄樱桃谷种鸭进行人工感染试验,试验分母鸭接种强毒组,公鸭接种强毒组和对照组。强毒接种4 d后,每隔2 d每组各迫杀2只,采集母鸭卵巢、卵泡、输卵管组织,公鸭采集睾丸、输精管进行病毒分离鉴定,并利用RT-PCR方法进行病毒F基因的扩增与同源性分析。同时,以NDV F蛋白的单克隆抗体(MAb)为一抗,建立间接免疫荧光检测方法检测输卵管组织中NDV及病毒在输卵管的分布情况。结果表明采用RT-PCR方法能够在种鸭生殖系统各个组织中检测并重新分离到NDV;输卵管子宫部和蛋白分泌部纤毛柱状上皮的纤毛细胞和分泌细胞内有阳性荧光信号存在。结果表明人工感染的种鸭卵巢、卵泡、睾丸、输精管以及输卵管子宫部和蛋白分泌部纤毛柱状上皮的纤毛细胞和分泌细胞中均有NDV分布,病毒能否随蛋白分泌、精液的排泄进入种蛋传递给雏鸭还有待于进一步研究。     

Jasmonic acid and abscisic acid play important roles in host–pathogen interaction between Fusarium graminearum and wheat during the early stages of fusarium head blight

The effect of phytohormones on the defense response of wheat against Fusarium graminearum infection was investigated. Infection of heads with F. graminearum induced accumulation of salicylic acid (SA), jasmonic acid (JA), abscisic acid (ABA), and indole acetic acid (IAA). Exogenous phytohormone treatments showed crosstalk between them and a complex effect on expression of the genes ATB2, ExpB6, LEA Td16, PR1, Pdf1.2, PR4. JA treatment reduced F. graminearum growth and fusarium head blight (FHB) symptoms while an increase in FHB was observed with ABA. Transient down-regulation of allene oxide synthase (AOS) supports a complex role for JA in wheat head.     

Pathogenicity of emerging Japanese type 1 porcine reproductive and respiratory syndrome virus in experimentally infected pigs

To clarify the pathogenicity of Japanese type 1 porcine reproductive and respiratory syndrome virus (PRRSV) isolate in experimentally infected pigs, we evaluated clinical signs and monitored viremia for 21 days post-inoculation (dpi). Lungs were mottled, tanned and reddish in appearance; had lesions predominantly in the cranial, middle and accessory lobes; and failed to collapse at 10 dpi. Although microscopic lesions of lungs were reproduced using the Japanese emerging type 1 PRRSV isolate under experimental conditions, no significant differences were noted between the challenge and control groups regarding mean rectal temperature and daily weight gain. These results provide useful insights into the limited pathogenicity of single infection with the Japanese type 1 PRRSV isolate in piglets, which differ from findings in reported field cases.     

种公猪精液中猪瘟和蓝耳病病毒混合感染的快速检测

参考GenBank公布的猪蓝耳病病毒(PRRSV)VL2332株、LV株以及猪瘟兔化弱毒(CSFV)C株的基因序列,各设计合成了一对引物,建立了在相同PCR扩增条件下能同时检测PRRSV和CSFV的RT-PCR方法。对2003~2004年期间江苏、浙江、安徽、福建、上海等省市的17个大中型猪场送检的186份种公猪精液进行了检测,结果18份呈PRRSV阳性,24份呈CSFV阳性,其中有11份为PRRSV和CSFV的混合感染,约占送检精液样品的5.91%。试验结果表明,所建立的RT-PCR方法可用于精液中这2种野毒感染的快速鉴定和分子流行病学调查。     

PCR技术检测猪伪狂犬病毒及其潜伏感染部位的研究

本研究合成了伪狂犬毒糖蛋白ｇｐ５０基因引笺，该引物能够扩增糖蛋白ｇｐ５０基因中４３４－６５１之间的２１７ｂｐＤＮＡ片段，该片段含 ＳａｌＩ酶切位点，应用引物对几种不同的伪狂犬病毒株多聚酶链式反应扩增结果全为阳性。     

IBV陕西分离株人工感染雏鸡的临床病理学研究

用ＩＢＶ陕西分离株Ｘ，Ｆｕ，Ｗ和Ｈ株人工感染４０日龄和１９日龄的雏鸡复制人工病例，对其临床症状、大体病变和病理组织学变化进行了较详细的研究。结果表明，ＩＢＶ陕西分离株具有较强的致病力，不仅能引起雏鸡发生呼吸道症状，而且可致严重的肾脏损伤，对１９日龄鸡引起的临床症状和病理损害均比４０日龄鸡更为严重。感染４０日龄和１９日龄鸡后，潜伏期、致死雏鸡的时间与病程分别为３８～７２ｈ和３２～４０ｈ，９６ｈ和４８ｈ及２５ｄ和７ｄ．     

Emerging viral zoonoses: frameworks for spatial and spatiotemporal risk assessment and resource planning

Spatial epidemiological tools are increasingly being applied to emerging viral zoonoses (EVZ), partly because of improving analytical methods and technologies for data capture and management, and partly because the demand is growing for more objective ways of allocating limited resources in the face of the emerging threat posed by these diseases. This review documents applications of geographical information systems (GIS), remote sensing (RS) and spatially-explicit statistical and mathematical models to epidemiological studies of EVZ.Landscape epidemiology uses statistical associations between environmental variables and diseases to study and predict their spatial distributions. Phylogeography augments epidemiological knowledge by studying the evolution of viral genetics through space and time. Cluster detection and early warning systems assist surveillance and can permit timely interventions. Advanced statistical models can accommodate spatial dependence present in epidemiological datasets and can permit assessment of uncertainties in disease data and predictions. Mathematical models are particularly useful for testing and comparing alternative control strategies, whereas spatial decision-support systems integrate a variety of spatial epidemiological tools to facilitate widespread dissemination and interpretation of disease data. Improved spatial data collection systems and greater practical application of spatial epidemiological tools should be applied in real-world scenarios.     

6种日本核型多角体病毒对斜纹夜蛾幼虫致病性的研究

从日本引进6种核型多角体病毒(NPV),保存5年后仍对斜纹夜蛾幼虫持有致病性。其中斜纹夜蛾核型多角体病毒(福山株)、甘蓝夜蛾核型多角体病毒(芸北株)、粘虫核型多角体病毒(芸北株)、八字地老虎核型多角体病毒(那须株)均保持较强的致病力,其剩余侵染力在1/1.34~1/2.50间。甘蓝夜蛾核型多角体病毒(东京株)的致病力下降最大,剩余侵染力为1/17.5、其次为海灰翅夜蛾核型多角体病毒(埃及株),剩余侵染力为1/7.01。