猪繁殖与呼吸综合征病毒GP5、M蛋白基因的克隆及其基因疫苗构建

参照GenBank中猪繁殖与呼吸综合征病毒(PRRSV)美洲型代表株VR2332 GP5和M蛋白基因序列,设计并合成2对引物,用RT-PCR方法分别扩增出PRRSV野毒株GP5和M蛋白基因603,525bp片段,并将其分别克隆到pMD18-T载体。测序正确后,将GP5和M蛋白基因分别克隆到真核表达载体pEGFP-C1上,成功构建基因疫苗表达载体pEGP5-C1和pEM-C1。小鼠免疫试验证实,这些基因疫苗质粒可以诱导小鼠产生特异性抗体,并在二免后1周开始检测到特异性淋巴细胞增殖反应。     

传染性喉气管炎病毒WG株糖蛋白gJ基因的克隆与表达

根据GenBank中已发表的传染性喉气管炎病毒全基因组序列（NC006233）设计引物,以传染性喉气管炎病毒WG株基因组为模板,PCR扩增糖蛋白gJ基因,并对其进行序列分析。用DNAStar软件分析酣蛋白的抗原性,选择抗原性强的140aa-483aa片段,克隆并连接到原核表达载体pET-32a（＋）中,转化BL21（DE3）菌株。经IPTG诱导后,获得大小为65．2ku的重组蛋白,命名为卜出,表达量占菌体蛋白总量的60．8％;Westernblot分析表明r-gJ具有较强的抗原性。     

Infection with Menangle virus in flying foxes (Pteropus spp.) in Australia

Objective To examine flying foxes (Pteropus spp.) for evidence of infection with Menangle virus. Design Clustered non‐random sampling for serology, virus isolation and electron microscopy (EM). Procedure Serum samples were collected from 306 Pteropus spp. in northern and eastern Australia and tested for antibodies against Menangle virus (MenV) using a virus neutralisation test (VNT). Virus isolation was attempted from tissues and faeces collected from 215 Pteropus spp. in New South Wales. Faecal samples from 68 individual Pteropus spp. and four pools of faeces were examined by transmission EM following routine negative staining and immunogold labelling. Results Neutralising antibodies (VNT titres ≥ 8) against MenV were detected in 46% of black flying foxes (P. alecto), 41% of grey‐headed flying foxes (P. poliocephalus), 25% of spectacled flying foxes (P. conspicillatus) and 1% of little red flying foxes (P. scapulatus) in Australia. Positive sera included samples collected from P. poliocephalus in a colony adjacent to a piggery that had experienced reproductive disease caused by MenV. Virus‐like particles were observed by EM in faeces from Pteropus spp. and reactivity was detected in pooled faeces and urine by immunogold EM using sera from sows that had been exposed to MenV. Attempts to isolate the virus from the faeces and tissues from Pteropus spp. were unsuccessful. Conclusion Serological evidence of infection with MenV was detected in Pteropus spp. in Australia. Although virus‐like particles were detected in faeces, no viruses were isolated from faeces, urine or tissues of Pteropus spp.     

禽流感病毒分子生物学的研究进展

禽流行性感冒(av ian in fluenza,A I,简称禽流感)是由A型禽流感病毒(av ian in fluenza v irus,A IV)引起的禽类烈性传染病。作为被世界动物卫生组织(O IE)定为A类的传染病,A I不仅给世界养禽业造成了巨大的经济损失,而且对人类健康和生命安全构成了严重威胁。因此,A I已经成为人们关注的焦点,国内外学者也对其进行了大量研究。作者从病原基因组及其编码的蛋白质、致病力、变异性以及对人类感染A IV的分子机制等角度就A IV的分子生物学研究作一综述,为防制A I提供理论基础,并在此基础上探讨了人类禽流感的防治措施,加深人们对A I的认识。     

西藏兔病毒性出血症的研究--病原鉴定及疫苗免疫效力试验

１９９４年６￣７月,西藏林芝地区家兔大批急性死亡同,经过流行病学调查,临诊断症状观察,病理剖检等结果与兔病毒性出血症特征相符。进一步作病毒学检查表明,病变组织超薄发切片经电子显微镜观察发现有大量直径约３０ｎｍ的球状裸听病毒粒子,自然病死兔肝组织匀交涉 清能凝集入）型红细胞,而且血凝兔出血症病毒阳性抗血清所抑制,致病性试验结果表明,该病毒对兔有很强的致病性;用西藏自然病死兔肝组织匀浆试制的矩形疫苗兔     

The fat content of milk from dairy cattle infected with bovine leukosis virus

Two groups of cows infected with the bovine leukosis virus (BLV) were kept on two different diets and the fat content of their milk was assayed. The results were compared with those obtained from two comparable groups of BLV-free cows. The cows in each group were of similar ages, those in the groups on the poorer diet being 1–4 months post partum, while those on the richer diet were 5–7 months post partum. The mean percentage of fat in the milk from uninfected cows on the poorer diet was 2.94 while that from the similar infected cattle was 3.06. Uninfected cows on the richer diet produced milk containing 3.39% fat, while those that were infected produced milk containing 3.30% fat. No statistical differences in milk fat production were observed between the BLV seropositive and seronegative cows.     

IMC10200株ALV-J实验诱发禽骨髓性白血病的研究

对分离自肉种鸡群亚临床感染的J亚群禽白血病病毒IMC1o200株进行了实验感染诱发禽骨髓性白血病的病理学研究.IMC10200株J亚群禽白血病病毒尿囊腔接种11日龄肉鸡胚和SPF蛋鸡胚,孵出后跟踪观察.9周龄时随机抽检感染鸡,感染肉鸡特异引物PCR检测全部为阳性;组织病理学观察感染鸡无明显病变.至21周龄时感染肉鸡出现第一例典型骨髓性白血病病例;感染SPF蛋鸡未见明显J亚群禽白血病相关病变.     

Experimental studies with foot-and-mouth disease virus type Asia-1, responsible for the 2005 epidemic in China

This study was carried out to investigate the biological characteristics of the foot-and-mouth disease (FMD) virus strain Asia-1 China/2005, which is responsible for the 2005 epidemic in China. The result showed that this strain is not host restricted, and could not only cause FMD in cattle and sheep but also in pigs by either inoculation or direct contact.     

伪狂犬病毒GDSH株的分离鉴定及gE基因的序列分析

从广东四会某猪场分离到一株疑为猪伪狂犬病病毒(PRV)的病毒,病毒在猪肾细胞上出现细胞变圆、拉网、融合等典型病变,并具有细胞泛嗜性特点。在MDCK细胞上测得其TCID50值为10-8/0.1mL,能被伪狂犬病病毒标准阳性血清中和。将0.1mL病毒液接种小鼠后发生奇痒并麻痹致死,接种猪3天后发病,7天死亡,从攻毒病死猪的脑组织病理切片上观察到典型的病毒性脑膜脑炎及血管套现象。通过PCR扩增到PRVgD基因,由此进一步证明所分离病毒为猪伪狂犬病毒,并命名为GDSH株。根据GenBank中发表的序列,设计一对扩增PRVgE基因的特异性引物,建立可以区分PRV野毒株与疫苗株的PCR诊断方法。以此方法对病毒的细胞培养液进行检测,结果证实所分毒株为PRV野毒株,经克隆测序后与GenBank收录的其它PRVgE基因序列进行比较,发现所测毒株的核苷酸序列与其它PRV毒株的同源性介于98.3%～99.9%之间,其中与PRVEa株的亲缘关系最近为99.9%。