植物源杀菌剂大黄素甲醚对烟草病毒病的防治效果

为明确大黄素甲醚对烟草病毒病的防治效果,最佳施药时期及施用量。以0.1%大黄素甲醚水剂为试验药剂,8%宁南霉素水剂和20%盐酸吗啉胍可湿性粉剂为对照,开展田间小区试验。结果表明,0.1%大黄素甲醚水剂于移栽定植期施药防效最好,高浓度达62.81%,中、高浓度即制剂量80克/亩、100克/亩的防效与对照药剂均无显著性差异。田间观察发现大黄素甲醚对烟草有一定促生长作用。     

河南省樱桃谷鸭乙型肝炎病毒全基因组克隆与序列分析

对河南省樱桃谷鸭主产区信阳、新郑、焦作三地628份樱桃谷鸭血清样本应用PCR技术进行鸭乙型肝炎病毒（DHBV）检测,并将三地DHBV阳性样本各挑选1份进行DHBV全基因的扩增、克隆、测序及序列分析。结果显示,信阳、新郑、焦作三地樱桃谷鸭DHBV自然携带率分别为10.5%、8.9%、17.6%;3株DHBV基因组全长分别为3 021、3 027、3 024bp,均含有编码P、S和C蛋白的3个开放阅读框,各开放阅读框氨基酸同源性比较显示差异显著的区域位于P蛋白。序列分析显示,3株DHBV河南株核苷酸同源性为89.8%~93.9%,与参考株为89.4%~99.5%。遗传进化分析及P蛋白关键位点分析结果表明,信阳分离株为西方基因型,其余2株为中国基因型。本试验掌握了河南省樱桃谷鸭主产区DHBV自然感染情况,并成功克隆了3株樱桃谷鸭DHBV全基因序列,为该病毒的进一步研究提供了有益信息。     

Two Akabane virus glycoprotein Gc domains induce neutralizing antibodies in mice

Akabane virus (AKAV), belonging to the genus Orthobunyavirus and family Peribunyaviridae, causes reproductive and congenital abnormalities in ruminants. Its envelope glycoprotein Gc is a neutralizing antigen, on which at least five distinct antigenic regions have been identified. We attempted to identify the domains using truncated recombinant AKAV Gc proteins expressed in Escherichia coli and monoclonal antibodies (mAbs) with AKAV-neutralizing activity. Dot blot analysis revealed that amino acid positions 1–97 and 189–397 (Gc_1–97 and Gc_189–397) in the truncated recombinant proteins reacted with the mAbs. Additionally, AKAV was neutralized by sera from mice immunized with these recombinant proteins. The results suggested that the two domains contain neutralizing epitopes and could be potential subunit vaccines against AKAV.     

Nationwide survey of hepatitis E virus infection among wildlife in Japan

In Japan, hepatitis E virus (HEV) causes hepatitis in humans through the consumption of raw or undercooked meat, including game meat. In the present study, nationwide surveillance of HEV infection among a total of 5,557 wild animals, including 15 species, was conducted in Japan. The prevalence of anti-HEV antibodies in wild boar was 12.4%, with higher positive rates in big boars (over 50 kg, 18.4%) than in small individuals (less than 30 kg, 5.3%). Furthermore, HEV RNA was more frequently detected in piglets than in older boars. Interestingly, the detection of HEV among wildlife by ELISA and RT-PCR suggested that HEV infection in Sika deer was a very rare event, and that there was no HEV infection among wild animals except for wild boar, Sika deer and Japanese monkeys. In conclusion, wild boar, especially piglets, are at high risk of HEV infection, while other wild animals showed less risk or no risk of HEV transmission.     

A molecular marker linked to the Prv1 gene that confers resistance to Papaya ringspot virus-type W in melon

Papaya ringspot virus‐type W (PRSV‐W) is the most prevalent and important viral pathogen of cucurbits in Brazil. It can be effectively controlled by the incorporation of genetic resistance into susceptible melon cultivars. The present study identified amplified fragment length polymorphic (AFLP) markers linked to the PRSV‐W resistance Prv¹ allele. The susceptible yellow‐fleshed melon‐breeding line AF426^prv1 and its nearly isogenic‐resistant line AF426^Prv1, which carries the Prv¹ allele resident in the Indian cantaloupe U.S. Plant Introduction (PI) 180280, were screened for AFLP marker polymorphisms. Of 30 251 AFLP loci, only three were polymorphic between the nearly isogenic lines. Segregation analyses for these three polymorphic markers and the Prv¹ allele using a BC₁ population of 197 plants indicated close linkage (0.5% recombination frequency) between marker EK190 (HindIII‐CGA and MseI‐GTG; 190 bp) and Prv¹. Thus, EK190 might be a useful marker in breeding programmes aiming to develop melon cultivars resistant to PRSV‐W. The other two markers are closely linked to each other, but distantly linked to Prv¹.     

猪脐静脉血管内皮细胞的分离及体外培养研究

为建立一种操作简单并且能获得大量猪血管内皮细胞的分离培养方法,本研究采集新生健康长白猪脐带,取其脐静脉血管,灌注0.1%的Ⅰ型胶原酶,于37℃水浴消化10 min后收集内皮细胞,培养于含20%胎牛血清的M199培养基中,长满单层后用胰酶消化传代培养。并对培养的细胞形态学、相关抗原和其他特征以及对病毒的易感性进行鉴定。结果表明,Ⅰ型胶原酶消化后可获得大量内皮细胞,细胞培养后的形态学观察显示细胞贴壁生长良好,呈典型的铺路石状排列;第Ⅷ因子相关抗原和细胞摄取乙酰化低密度脂蛋白均呈阳性,内皮细胞比率可高达100%。传3代后的生长曲线显示细胞传代后延迟期小于1 d,对数生长期约3 d,第5 d进入平台期,第7 d开始脱落死亡。病毒感染试验表明所获得的内皮细胞对猪瘟病毒高度易感,病毒生长与常用的PK-15没有区别。上述研究结果表明本研究建立的血管内皮细胞分离培养方法简便有效,为大量制备原代血管内皮细胞提供了可靠的方法。     

四种限制性内切酶对美国白蛾核型多角体病毒DNA酶解分析

从HcNPV中直接分离提纯的DNA证明具有典型的紫外吸收光谱。经琼脂糖电泳后是一条带谱。用限制性内切酶EcoRⅠ、PstⅠ、BglⅡ、PVUⅡ酶解,经琼脂糖平板电泳分别产生19、22、18、22条核酸片段。以λDNA-EcoRⅠ和λDNA-HindⅢ片段作参考,计算出各片段分子量大小,积加得平均值为94.0445×10~8。     

利用反向遗传技术拯救H9N2重组病毒

为研制高效特异的H9N2亚型AI疫苗,选取我国具有代表性的毒株A/chicken/Shanghai/10/01(H9N2)(简称SH10),以12质粒系统为基础,利用反向遗传操作技术构建了1株表面基因由SH10提供、内部基因由12质粒系统提供的重组病毒SH/PR8,为新型疫苗的研制提供了新的毒株。     

Substitution of vaccinia virus Elstree by modified vaccinia virus Ankara to test the virucidal efficacy of chemical disinfectants

After the eradication of variola in 1980, the smallpox vaccination was considered to be no longer required and was subsequently abandoned mainly because of possible adverse effects of vaccinia virus especially in first‐time vaccinees. Despite a growing number of humans without immunity against vaccinia virus, vaccinia virus Lister Elstree (VACV) is still prescribed for testing virucidal efficacy of chemical disinfectants in the guidelines of the German Veterinary Medical Society [Deutsche Veterinärmedizinische Gesellschaft (DVG)], the German Association for the Control of Virus Diseases [Deutsche Vereinigung zur Bekämpfung der Viruskrankheiten (DVV)] and the Robert Koch Institute (RKI). To evaluate a possible substitution of VACV, with the attenuated modified vaccinia virus Ankara (MVA) the virucidal efficacy of four different DVG‐listed commercially available chemical disinfectants representing different groups of chemicals was tested against these two viruses. Quantitative suspension tests and qualitative carrier tests with poplar wood and gauze were performed. Distinction of VACV and MVA was confirmed by cytopathogenic effects, such as differences in plaque morphology. No significant difference in disinfection efficacy between VACV and MVA was observed for any of the disinfectants tested. Implying that vaccinia virus poses a risk after inadvertent inoculation, our results show that MVA, which does not replicate in humans, should replace VACV in the chemical disinfectant testing guidelines.