乌鸡传染性法氏囊病毒的分离鉴定与分子生物学特性研究

从一群精神不振、拉白色稀粪便为特征的乌鸡中分离到 1株病毒。经血清学试验、鸡胚接种试验、动物回归试验等鉴定为法氏囊病毒。该病毒与鸡法氏囊病毒的血清型无明显差异。根据IBDV的VP2基因序列设计了一对特异性引物 ,应用RT -PCR法从中扩增出了一条0 .72kb的VP2基因高变区片段。序列分析表明 ,片段长 0 .72kb ,编码 2 4 0个氨基酸 ,与其他毒株的VP2基因序列比较分析 ,该毒株符合IBDV超强毒的特征。虽然有 4处氨基酸发生了变化 ,但没有引起其抗原性的改变     

鸭疫里氏杆菌和大肠杆菌二联灭活疫苗研究

将鸭疫里氏杆菌(RA)通过加有血清的改良肉汤培养，得菌数在520亿—2000亿／mL的菌液；鸭大肠杆菌(E．coli)通过普通肉汤培养，得菌数在1000亿～5000亿／mL的菌液，将两茵液甲醛灭活后以2.5：1的比例混合，再与灭菌的油乳剂以2：5的比例强力搅拌，制成二联油乳剂灭活疫苗，经无菌检验，安全检验合格后，做免疫保护试验，免疫6日龄雏鸭(0．5mL/只)，于18天后攻毒(RA：0．2mL／只；E.coli：0．1mL/只)，保护率分别为75％和50％；6日龄一免，14日龄二免(均0．5mL/只)，于二免后11天攻毒，保护率分别为100％和80％。     

上海地区近几年鸭新发病毒性传染病的血清学调查

于2003年从上海市5个区17个养鸭场(户)的鸭群中采集276份血清样品，采用进口ELISA试剂盒对冠状病毒、传染性法氏囊病毒、新城疫病毒、产蛋下降综合征病毒的感染状况进行了血清学调查。结果表明，受检鸭群存有不同程度的阳性率，原来只感染鸡的疫病逐步向鸭群延伸。     

Genome analysis and development of infectious cDNA clone of a virulence-attenuated strain of foot-and-mouth disease virus type Asia 1 from China

The RNA genome sequence of the rabbit passage-attenuated strain of foot-and-mouth disease virus (FMDV) Asia 1, ZB/CHA/58(att), was determined to be 8165 nt in length excluding the poly(C) tract in the 5′ UTR and the poly(A) tail at the 3′ end. ZB/CHA/58(att) was most similar to the vaccine strain Asia 1/YNBS/58 in genome sequence and there were no deletions or insertions within the deduced polyprotein between ZB/CHA/58(att) and YNBS/58, but there were a total of 25 substitutions at the amino acid level and an extra 19-nt stretch in the 5′ UTR was found in ZB/CHA/58(att). An infectious full-length cDNA clone of ZB/CHA/58(att) was developed. Infectious virus could be recovered in BHK-21 cells transfected with the synthetic viral RNA transcribed in vitro. The plaque morphology, growth kinetics and antigenic profile of the infectious clone-derived virus (termed tZB) were indistinguishable from those induced by the parental virus. Furthermore, the virulence properties of ZB/CHA/58(att) and tZB were found to be highly similar in the mouse model. The availability of genome sequence information and infectious cDNA clone of the FMDV ZB/CHA/58(att) lays a new ground for further investigation of FMDV virulence determinants and development of new potent vaccine to FMD.     

Equine Herpesvirus-1 Consensus Statement

Equine herpesvirus-1 is a highly prevalent and frequently pathogenic infection of equids. The most serious clinical consequences of infection are abortion and equine herpesvirus myeloencephalopathy (EHM). In recent years, there has been an apparent increase in the incidence of EHM in North America, with serious consequences for horses and the horse industry. This consensus statement draws together current knowledge in the areas of pathogenesis, strain variation, epidemiology, diagnostic testing, vaccination, outbreak prevention and control, and treatment.     

表达传染性喉气管炎病毒gB基因重组鸡痘病毒疫苗的遗传稳定性评价

为了检测表达鸡传染性喉气管炎病毒糖蛋白gB基因重组鸡痘病毒（rFPV-ILTVgB)的稳定性，我们对重组病毒进行6代和16代克隆纯化，对纯化后的病毒通过转瓶连续培养传20代，结果发现第6代纯化病毒（rFPV-ILTVgB-C6)在传代过程中有白斑出现，说明病毒纯度不够；经过16代纯化的病毒（rFPV-ILTVgB-C16)对细胞的嗜性加强，病毒的效价进一步升高，20代传代后蓝斑率仍然为100％，PCR的检测进一步证明插入的外源基因能在病毒的长期传代过程中稳定地遗传。抽取病毒细胞传代过程中的第5，10，15，20代次的病毒翅膀内侧无血管处皮下接种2周龄SPF鸡，20天后分为两组，分别用传染性喉气管炎病毒WG株和鸡痘病毒102株攻击，结果不同代次的重组病毒均可以使免疫鸡抵抗传染性喉气管炎病毒和鸡痘病毒强毒的攻击，鸡体内病毒传代试验表明，重组病毒在接种部位仅存在6天，之后就检测不到病毒，重组病毒通过SPF鸡连续传代，不存在病毒返祖的可能，由此可以得出一个结论：rFPV-ILTVgB在结构上和免疫原性上是稳定的，无论是在体外传代，还是在体内均可以稳定遗传，不存在因为接种重组疫苗而给免疫鸡群带来安全威胁的可能，完全可以作为疫苗毒株进行商品化开发。     

Insertion and stable expression of Gaussia luciferase gene by the genome of bovine viral diarrhea virus

As a tool to address selected issues of virus biology, we constructed a recombinant cDNA clone of bovine viral diarrhea virus (BVDV) expressing Gaussia luciferase (Gluc) reporter gene. A full-length genomic cDNA clone of a non-cytopathic BVDV isolate was assembled by recombination in yeast Saccharomyces cerevisiae. The Gluc gene was inserted between the N^pro and Core protein coding regions by recombination. The cDNA transcribed in vitro was infectious upon transfection of MDBK cells, resulting in reporter gene expression and productive virus replication. The rescued viruses were stable for 15 passages in cell culture, maintaining the replication kinetics, focus size and morphology similar to those of the parental virus. Expression and correct processing of the reporter protein were also maintained, as demonstrated by Gluc activity. These results demonstrate that genes up to 555 bp are simply assembled by a single step in yeast recombination and are stably expressed by this cDNA clone.     

传染性支气管炎病毒疫苗研究进展

传染性支气管炎给我国规模化养鸡业造成巨大的经济损失,由此尝试研制重组鸡痘病毒传染性支气管炎病毒基因工程疫苗了解其免疫效应,以期获得高效而安全的基因工程疫苗。为更好地了解鸡传染性支气管炎的防治现状,文章从各种表达载体系统表达传染性支气管炎病毒蛋白的优缺点及其产生免疫保护效应的角度,对近年来传染性支气管炎病毒疫苗研究的发展状况做了简要概述,且针对传染性支气管炎病毒基因工程疫苗现存的问题,展望了将来的发展趋势。     

安徽省白羽肉鸡中副鸡禽杆菌的分离鉴定及流行病学分析

本研究试图通过病原分离对安徽省某大型白羽肉鸡养殖公司持续出现疑似鸡传染性鼻炎的鸡群进行确诊,从不同批次发生鸡传染性鼻炎疑似症状的鸡体内分离细菌,经细菌分离、纯化、回鸡试验,共分离到8株细菌,经形态及培养特性、生化试验、血清学特性、16S rRNA基因序列分析等方法对分离的细菌进行鉴定。结果表明所分离的细菌有1株为A型副鸡禽杆菌,7株为B型副鸡禽杆菌,说明在安徽省某地持续引起幼龄肉鸡发生鸡传染性鼻炎的流行中B型致病株是优势毒株,显示新的流行特点。     

Epidemiological Study of Pestiviruses in South American Camelids in Switzerland

Background: In the context of the ongoing eradication campaign for bovine viral diarrhea virus (BVDV) in cattle in Switzerland, the role of South American camelids (SAC) as a possible virus reservoir needed to be evaluated. Objective: To assess and characterize the prevalence of pestivirus infections in SAC in Switzerland. Animals: Serum samples collected from 348 animals (40 herds) in 2008 and from 248 animals (39 herds) in 2000 were examined for antibodies against pestiviruses and for the presence of BVDV viral RNA. Methods: Cross‐sectional study using stratified, representative herd sampling. An indirect BVDV‐ELISA was used to analyze serum samples for pestivirus antibodies, and positive samples underwent a serum neutralization test (SNT). Real‐time RT‐PCR to detect pestiviral RNA was carried out in all animals from herds with at least 1 seropositive animal. Results: In 2008, the overall prevalence of animals positive for antibodies (ELISA) and pestiviral RNA or was 5.75 and 0%, respectively. In 2000, the corresponding prevalences were 3.63 and 0%, respectively. The seroprevalences (SNT) for BVDV, border disease virus or undetermined pestiviruses were estimated to be 0, 1.73, and 4.02% in 2008, and 0.40, 1.21, and 2.02% in 2000, respectively. Conclusions and Clinical Importance: At the present time, SAC appear to represent a negligible risk of re‐infection for the BVDV eradication program in cattle in Switzerland.