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1.
The classical swine fever (CSF) epidemic in the Netherlands in 1997-1998 lasted 14 months, during which 429 infected and 1300 at risk herds were culled, at an estimated economical cost of 2 billion US dollars. Despite the overwhelming scale of the epizootic, the CSF virus (CSFV) strain causing the outbreak has remained largely uncharacterized. The Dutch epizootic is epidemiologically linked to a small CSF outbreak in 1997, in Paderborn in Germany. E2 and partial 5' NTR sequencing has shown that the index Paderborn isolate, and several Dutch isolates taken during the 1997-1998 epizootic, are virtually identical, confirming that the Paderborn isolate triggered the Dutch outbreak, and furthermore showing that this single isolate was stable throughout the whole Dutch outbreak (the above reviewed in [C. Terpstra, A. J. de Smit, Veterinary Microbiol. 77 (2000) 3-15]). We determined the nucleotide sequence of the 5' NTR (by 5' RACE) and the complete open reading frame of the Paderborn isolate (GenBank AY072924). Our sequence was identical to previously published partial 5'NTR and E2 sequences for the index Paderborn 1997 and Dutch 1997 (Venhorst) isolates, confirming the identity of the virus we sequenced. Phylogenetic analysis based on the complete open reading frame showed that Paderborn is genetically very different from common European laboratory reference strains. Neutralization studies showed that Paderborn is also antigenically very different from common laboratory strains such as Alfort 187. Paderborn is the only recent European CSFV field isolate for which a complete sequence is available, and given Paderborns genetic and antigenic uniqueness, the Paderborn sequence may have practical use for diagnostic and vaccine antigen development. 相似文献
2.
Molecular epidemiology of classical swine fever in Italy 总被引：5，自引：0，他引：5
To gain an insight into the molecular epidemiology of classical swine fever (CSF) in Italy, virus isolates originating from outbreaks that occurred between 1985 and 2000 in wild boar or in domestic pigs in mainland Italy and in Sardinia were analysed by genetic typing. For this, a fragment (190 nucleotides) of the E2 glycoprotein gene was sequenced and phylogenetic analyses were performed, including older Italian isolates and isolates from recent outbreaks in Europe for comparison. The results show that in mainland Italy, several independent epidemiological events occurred in the last decade. In the north of the country, viruses of genotype 2.2 have persisted in wild boar, causing sporadic outbreaks in domestic pigs. In contrast, viruses of subgroups 2.1 and 2.3 appeared only intermittently in different regions of the mainland. In 1997, classical swine fever virus (CSFV) isolates belonging to the subgroup 2.1 and genetically and epidemiologically related to the Dutch isolate in Venhorst, affected domestic pigs exclusively. The isolates of subgroup 2.3, derived from wild boar as well as from domestic pigs were closely related to isolates from Germany and Poland. In Sardinia, CSF is an endemic in wild boar and affects domestic pigs also. Genetic typing showed that viruses of subgroups 1.1 and 2.3 have been present, the last ones being unrelated to the mainland viruses of the same subgroup. Due to the large quantities of pig and wild boar meat imported in some parts of Italy, it cannot be established if these viruses were always present in either the mainland or Sardinia, or if they represent recent introductions. 相似文献
3.
Vlasova A Grebennikova T Zaberezhny A Greiser-Wilke I Floegel-Niesmann G Kurinnov V Aliper T Nepoklonov E 《Journal of veterinary medicine. B, Infectious diseases and veterinary public health》2003,50(8):363-367
The ability to discriminate between various classical swine fever virus (CSFV) strains and isolates is a prerequisite for following the spread of the virus after an outbreak. To determine the relatedness between Russian CSFV isolates from different geographical regions, three fragments of the viral genome (5' NTR, the variable region of the E2 gene and a fragment of the NS5B gene) were sequenced and used for genetic typing. Thirty-one field isolates were obtained from CSF outbreaks which occurred between 1994 and 1999. In addition, three attenuated strains were included in the study, namely the LK and CS vaccine strains, and the moderately virulent 238H isolate. The vaccine strains have been used in Russia for more than 30 years. Our results showed that all field isolates are in subgroup 1.1 together with Alfort 187 and with the highly virulent strain Shimen. In contrast, the CS and LK vaccine strains belong to subgroup 1.2. While there is no evidence for the reversion of the two vaccine strains to wild type, it is feasible that the highly virulent Shimen strain, which has been used as a challenge strain for many years, contributed to field strain generation. The Russian field isolates from the 1990s can be distinguished from the CSF virus isolates which occurred in the EU Member States in the same decade, as here all outbreaks were caused by CSF viruses belonging to subgroup 2. 相似文献
4.
The envelope glycoprotein E2 of classical swine fever virus (CSFV) plays multiple roles in the viral life cycle, interaction with host and pathogenesis. We sequenced the E2 gene of 34 CSFV isolates from southeastern China for analysis of genetic diversity in this particular region. Phylogenetic analysis revealed that genotype 2.1b viruses became predominant in southeastern China with 33 isolates clustered in 2.1b and only 1 isolate belonged to 2.2. Pairwise comparisons demonstrated isolates in this study showed a homology of 78.4-82.6% to Chinese C-strain in the 190nt of the E2 fragment. The minimum similarity within the 2.1b isolates was 91.1%. Variability of the full length E2 amino acid sequences of 45 CSFV isolates representative of three main groups of CSFV including 19 from southeastern China during 2004--2007 and 26 from other parts of China and other countries was analyzed by the differences between non-synonymous (dN) and synonymous (dS) rates and the entropy values. Two variable and three conserved regions as well as some specific positions under positive selection were defined. Our results suggest that recent isolates from southeastern China have shifted away from historical CSFV isolates including the vaccine strains probably as a result of their adaptive abilities to the selection forces within the host. 相似文献
5.
Elber AR Stegeman A Moser H Ekker HM Smak JA Pluimers FH 《Preventive veterinary medicine》1999,42(3-4):157-184
The objective of this paper is to describe the severe epidemic of classical swine fever (CSF) in The Netherlands in 1997–1998 under a policy of non-vaccination, intensive surveillance, pre-emptive slaughter and stamping out in an area which has one of the highest pig and herd densities in Europe.
The primary outbreak was detected on 4 February 1997 on a mixed sow and finishing pig herd. A total of 429 outbreaks was observed during the epidemic, and approximately 700 000 pigs from these herds were slaughtered. Among these outbreaks were two artificial insemination centres, which resulted in a CSF-suspect declaration of 1680 pig herds (mainly located in the southern part of The Netherlands). The time between introduction of CSF virus (CSFV) into the country and diagnosis of CSF in the primary outbreak was estimated to be approximately 6 weeks. It is presumed that CSFV was spread from The Netherlands to Italy and Spain via shipment of infected piglets in the beginning of February 1997, before the establishment of a total stand-still of transportation. In June 1997, CSFV is presumed to be introduced into Belgium from The Netherlands.
Pre-emptive slaughter of herds that had been in contact with infected herds or were located in close vicinity of infected herds, was carried out around the first two outbreaks. However, this policy was not further exercised till mid-April 1997, when pre-emptive slaughter became a standard operational procedure for the rest of the epidemic. In total, 1286 pig herds were pre-emptively slaughtered. (approximately 1.1 million pigs). A total of 44 outbreaks (10%) was detected via pre-emptive slaughter.
When there were clinical signs, the observed symptoms in infected herds were mainly atypical: fever, apathy, ataxia or a combination of these signs. In 322 out of 429 outbreaks (75%), detection was bases on clinical signs observed: 32% was detected by the farmer, 25% by the veterinary practitioner, 10% of the outbreaks by tracing teams and 8% by screening teams of the veterinary authorities. In 76% of the outbreaks detected by clinical signs, the farmer reported to have seen clinical symptoms for less than 1 week before diagnosis, in 22% for 1–4 weeks before diagnosis, and in 4 herds (1%) the farmer reported to have seen clinical symptoms for more than 4 weeks before diagnosis.
Transportation lorries played a major role in the transmission of CSFV before the primary outbreak was diagnosed. It is estimated that approximately 39 herds were already infected before the first measures of the eradication campaign came into force.
After the first measures to stop the spread of CSFV had been implemented, the distribution of the most likely routes of transmission markedly changed. In most outbreaks, a neighbourhood infection was indicated.
Basically, there were two reasons for this catastrophe. Firstly, there was the extent of the period between introduction of the virus in the region and detection of the first outbreak. As a result, CSFV had opportunities to spread from one herd to another during this period. Secondly, the measures initially taken did not prove sufficient in the swine- and herd-dense region involved. 相似文献
6.
本试验利用PCR技术,扩增得到猪瘟病毒（CSFV）C株E2基因的主要抗原片段A/D区549 bp,将其酶切纯化后,与已酶切纯化的pET-32a进行16 ℃过夜连接,转化大肠杆菌BL21。从转化成功的氨苄培养板挑取合适菌落进行PCR,挑取目的条带正确的菌落加至LB培养基进行过夜培养后送测序。将测序正确的菌液划板,挑菌培养并用IPTG进行诱导表达。得到的蛋白进行SDS-PAGE,在约39 ku位置有蛋白条带。将蛋白纯化后,分别利用自制兔抗CSFV阳性血清及临床检测阳性的猪抗CSFV阳性血清进行Western blotting检测,可见在39 ku处有单一条带,表明表达的蛋白具有免疫原性。本试验结果为下一步ELSIA试剂盒的组装奠定基础,方便对猪场免疫猪群猪瘟抗体水平进行监控。 相似文献
7.
8.
During the hunting season 1996-1999, blood samples were collected from wild boar shot in The Netherlands. Sera were screened for presence of antibodies against classical swine fever virus (CSFV), swine vesicular disease virus (SVDV), Aujeszky's disease virus (ADV), and Trichinella spiralis. The results indicate that CSFV, SVDV, and ADV are uncommon in the wild boar population. Therefore, it seems that CSFV, SVDV, and ADV infection in the wild boar population is not an important reservoir in The Netherlands. ADV and CSFV infections are endemic in the wild boar population in Germany. Since contact between the German and Dutch wild boar populations can not be excluded, continuation of the sero-surveillance system seems appropriate. In the decade before 1998, the wild boar population in The Netherlands seemed to be free of T. spiralis. Whether the finding, in the hunting season of 1998-1999, of a few wild boar with antibodies against T. spiralis is an artefact or not, should be investigated in further research. 相似文献
9.
Molecular epidemiology of a large classical swine fever epidemic in the European Union in 1997-1998 总被引：1，自引：0，他引：1
Greiser-Wilke I Fritzemeier J Koenen F Vanderhallen H Rutili D De Mia GM Romero L Rosell R Sanchez-Vizcaino JM San Gabriel A 《Veterinary microbiology》2000,77(1-2):17-27
A big epidemic of classical swine fever (CSF) occurred in the European Community in 1997. The first case was reported at the beginning of January 1997 from Germany. The disease presumably spread to the Netherlands, and from there to Italy, Spain and eventually to Belgium. About 30 isolates from these outbreaks were analysed by comparison of the nucleotide sequence data generated from fragments of both the E2 glycoprotein gene (190 nucleotides) and from the 5'-nontranslated region (5'-NTR; 150 nucleotides). By combining epidemiological data with genetic typing, it was found that the outbreaks were related and caused by a virus belonging to the genetic subgroup 2.1. As this type of virus had been reported infrequently in Europe and not at all since 1993, we postulate that it was newly introduced into the European Union (EU). 相似文献
10.
Jemersić L Greiser-Wilke I Barlic-Maganja D Lojkić M Madić J Terzić S Grom J 《Veterinary microbiology》2003,96(1):25-33
During a period of 5 years (1997-2001) several outbreaks of classical swine fever (CSF) were recorded in Croatia. For genetic typing, fragments of 150 nucleotides within the 5'-non-translated region (5'-NTR) and 190 nucleotides within the E2 glycoprotein coding gene of nine field isolates that were derived from domestic pigs and wild boars were used. For better epizootiological understanding, isolates from other European countries were included in the study. The results show that the isolates belong to subgroups 2.1 and 2.3 of CSF virus. Isolates from subgroup 2.1 were collected from domestic pigs during sporadic outbreaks in June 1997 and are genetically closely related. A genomic similarity between these isolates and CSF virus isolates from pigs in other European countries from the same year could also be confirmed. In contrast, the isolate from October 1997 was found to be a member of subgroup 2.3, and is closely related to European CSF virus isolates from outbreaks in the last decade in Western and Central European countries. These results show that two different sources of CSF virus caused outbreaks in Croatia during the same year. Furthermore, a close relationship was found between an isolate from a domestic pig in 1999 and isolates of subgroup 2.3 that originated from Croatian wild boars. 相似文献
11.
Parchariyanon S Inui K Damrongwatanapokin S Pinyochon W Lowings P Paton D 《DTW. Deutsche tier?rztliche Wochenschrift》2000,107(6):236-238
Thirty classical swine fever viruses (CSFV) isolated in Thailand between 1988 and 1996 were characterised by genetic sequence analysis of a part of their E2 coding regions, comparing the new data with that for representative reference viruses from other countries and continents. Thai isolates were divided into three distinct genogroups, indicating multiple origins for the outbreaks. Eighteen isolates from 1988-1995 form a new genogroup not previously described from any other geographical region. Eleven isolates from 1988-1995 are in the same genogroup as old US and European strains represented by reference strains Alfort 187 and Brescia. The viruses of this group seem to have died out in Europe but still persist in Thailand. One recent isolate from 1996 represents another previously described genogroup being closely related to Italian viruses isolated in the same year. 相似文献
12.
猪瘟病毒低毒力毒株FJFQ株的分离鉴定 总被引：3，自引：0，他引：3
从福建某猪场分离到 1 株病毒,其在PK 15细胞上的毒价为 106.5 TCID50/mL,该病毒能被猪瘟病毒高免血清所中和(效价为1∶8)。通过 RT -PCR 扩增出猪瘟病毒约250 bp的E2蛋白主要抗原编码区序列,其与几株已发表毒株序列的核苷酸及氨基酸同源性分别为79.9%~87.9%,77.7%~86.6%,与Alfort 株同属于基因二群。经本动物传3代均不表现明显的临床症状。用猪瘟兔化弱毒疫苗免疫后以此分离毒作强攻进行免疫保护相关实验,结果免疫组猪在攻毒前及攻毒后扁桃体 HCFA检测均为阴性,对照组猪扁桃体HCFA于攻毒后1周开始出现阳性结果,且一直持续到试验结束。用分离株免疫本动物后再攻石门毒, 2 头试验猪中 1 头死亡,1头出现临床症状。初步说明,所分离的病毒为猪瘟病毒(命名为CSFV- FJFQ株),可能是一株低毒力毒株,且其免疫原性不好。 相似文献
13.
猪瘟病毒一步法RT PCR检测方法的建立 总被引：2，自引：1，他引：1
本研究根据NCBI公布的猪瘟病毒石门毒株的E2基因序列，设计、合成了1对检测猪瘟病毒E2基因的RT-PCR引物。自疑似猪瘟病料及接猪瘟F114毒的PK-15细胞中提取总RNA，经一步法RT-PCR扩增E2基因。建立了猪瘟病毒E2基因RT-PCR检测方法，RT-PCR从26份疑似猪瘟病料中检出阳性病料24份，阳性检出率为92.3%；结果表明，建立的 RT-PCR方法具有良好的特异性和敏感性，可用于CSFV的分离鉴定、临床病料的检测和分子流行病学调查。 相似文献
14.
Alexander DJ Banks J Collins MS Manvell RJ Frost KM Speidel EC Aldous EW 《The Veterinary record》1999,145(15):417-421
Antigenic and genetic analyses of viruses from the 11 outbreaks of Newcastle disease in Great Britain, 12 of the outbreaks in Northern Ireland and the single outbreak in the Republic of Ireland which occurred in 1997, indicated that they were all essentially similar. In addition, the viruses from the British Isles were very similar to viruses isolated from three outbreaks in pheasants in Denmark between August and November 1996, from a goosander in Finland in September 1996, from an outbreak in chickens in Norway in February 1997, and from an outbreak in chickens in Sweden in November 1997. Viruses from outbreaks in other countries during 1995 to 1997 could be distinguished antigenically and/or genetically from the 1996 to 1997 Scandinavian/British Isles isolates, as could viruses responsible for two separate outbreaks in caged birds in quarantine premises in Great Britain in March 1997. Minor nucleotide differences in the 413-base region of the fusion gene and the 187-base region of the haemagglutinin-neuraminidase gene sequenced in this study allowed the 1996 to 1997 Scandinavian/British Isles isolates to be divided into groups. These groups broadly corresponded to the clusters of disease outbreaks, but suggested that the discrete outbreak in Scotland was probably the result of virus spread from Northern Ireland. Overall, the antigenic and genetic analyses of these viruses were consistent with the theory that the virus was introduced into the British Isles by migratory birds moving from north-east Europe. However, it was not possible to rule out other sources, such as the movement of pheasants from Denmark. 相似文献
15.
为了解山西地区猪瘟病毒（CSFV）流行毒株的遗传变异情况,采用RT-PCR方法,2013年从山西部分地区分离出5株CSFV流行毒株,并进行了E2全基因扩增、克隆与序列测定,应用DNAStar分析软件对所测定的5株毒株与国内外参考毒株的相应序列进行了同源性分析,绘制系统发育进化树。结果表明：5株CSFV流行毒株之间E2基因核苷酸序列与所推导氨基酸序列的同源性分别为81.4%~100%和87.9%~100%,与CSFV石门毒株（Shimen株）的核苷酸与氨基酸的同源性分别为82.9%~94.8%和89.0%~94.9%,与CSFV兔化弱毒株（HCLV株）的核苷酸与氨基酸的同源性分别为81.6%~99.6%和87.9%~99.5%,与17株来自各国不同地区的CSFV参考毒株的核苷酸与氨基酸的同源性分别为81.5%~99.6%和86.3%~99.7%。经系统发育关系分析,4株属于基因2群,且705、713、725、729、734和738位氨基酸发生置换,另外1株属于基因1群。本研究揭示了山西猪瘟流行毒株的遗传变异多样性现状。 相似文献
16.
猪瘟病毒四川分离株E2基因的分子克隆、原核表达及免疫学活性分析 总被引：2，自引：2，他引：0
分子克隆猪瘟病毒(classical swine fever virus,CSFV)四川分离株E2基因,并对其进行原核表达及免疫学活性分析。PK-15细胞培养增殖CSFV四川分离株提取总RNA,运用RT-PCR扩增E2基因,定向克隆构建原核重组表达载体,转化E.coli Rosetta-gami-TM(DE3)plysS,IPTG诱导表达,SDS-PAGE检测蛋白表达,Western blotting分析表达蛋白的免疫学活性。试验结果表明,成功克隆了E2基因,共1119 bp,包含有编码E2蛋白的完整序列,编码373个氨基酸;成功构建了CS-FVE2基因完整阅读框、主要抗原区原核表达载体pET-E2(pe)、pET-mE2(pe);蛋白质电泳结果显示,成功表达出约45.32、28.49 ku两目的蛋白,而且表达的E2(pe)、mE2(pe)融合蛋白均能被CSFV阳性血清所识别,具有良好的免疫学反应活性。因此,本试验成功获得CSFV四川分离株E2基因,表达出具有生物学活性的E2(pe)、mE2(pe)融合蛋白。 相似文献
17.
猪瘟病毒E2基因的克隆及分子特性分析 总被引：1，自引：0，他引：1
为研究四川地区猪瘟病毒（classical swine fever virus,CSFV）及E2基因的遗传变异情况,试验对CSFV阳性病料抽提RNA,通过RT-PCR扩增CSFV E2基因并将其克隆到pMD18-T载体,经菌落PCR、双酶切、序列测定后利用生物信息学软件分析了E2基因的分子特性。结果显示,扩增的E2基因大小为1 125 bp,编码375个氨基酸,与GenBank中CSFV GXWZ02、CSFV/2.1、HEBZ、YC11WB、SXYL2006、0406/CH/01/TWN亲缘关系较近,核苷酸同源性分别为98.3%、96.5%、94.7%、92.4%、92.1%和90.9%,而与疫苗株HCLV E2的同源性较低,为87.6%。密码子偏向性分析显示,E2基因的ENc值为53.161,密码子使用频率与大肠杆菌、酵母菌和人差异较大的分别有33、25和25个;此外,E2基因共有34个稀有密码子,且有多个稀有密码子多次串联成簇的情况出现。结果表明,E2基因在密码子使用中整体上不存在较明显的偏向性,且密码子使用模式更接近真核生物,本试验克隆的E2基因与疫苗株相比,部分核苷酸出现了变异,但主要抗原域氨基酸未发生改变,该结果为进一步开展CSFV E2功能研究及后期基因工程苗的研制提供了基础数据。 相似文献
18.
Postel A Schmeiser S Bernau J Meindl-Boehmer A Pridotkas G Dirbakova Z Mojzis M Becher P 《Veterinary research》2012,43(1):50
ABSTRACT: Molecular epidemiology has proven to be an essential tool in the control of classical swine fever (CSF) and its use has significantly increased during the past two decades. Phylogenetic analysis is a prerequisite for virus tracing and thus allows implementing more effective control measures. So far, fragments of the 5′NTR (150 nucleotides, nt) and the E2 gene (190 nt) have frequently been used for phylogenetic analyses. The short sequence lengths represent a limiting factor for differentiation of closely related isolates and also for confidence levels of proposed CSFV groups and subgroups. In this study, we used a set of 33 CSFV isolates in order to determine the nucleotide sequences of a 3508-3510 nt region within the 5′ terminal third of the viral genome. Including 22 additional sequences from GenBank database different regions of the genome, comprising the formerly used short 5′NTR and E2 fragments as well as the genomic regions encoding the individual viral proteins Npro, C, Erns, E1, and E2, were compared with respect to variability and suitability for phylogenetic analysis. Full-length E2 encoding sequences (1119 nt) proved to be most suitable for reliable and statistically significant phylogeny and analyses revealed results as good as obtained with the much longer entire 5′NTR-E2 sequences. This strategy is therefore recommended by the EU and OIE Reference Laboratory for CSF as it provides a solid and improved basis for CSFV molecular epidemiology. Finally, the power of this method is illustrated by the phylogenetic analysis of closely related CSFV isolates from a recent outbreak in Lithuania. 相似文献
19.
Dilip Kumar SarmaNiranjan Mishra Stefan VilcekKatherukamem Rajukumar Sthita Pragnya BeheraRam Kumar Nema Pooja DubeyShiv Chandra Dubey 《Comparative immunology, microbiology and infectious diseases》2011,34(1):11-15
Classical swine fever (CSF), a highly contagious viral disease of pigs, is endemic in India. As there is no information concerning the accurate genetic typing of classical swine fever virus (CSFV) isolates in India, 16 CSF viruses isolated during 2005-2007 from domestic pigs in different districts of Assam were typed in 5′ UTR (150 nucleotides). To confirm the genetic typing results and to study the genetic variability, selected viruses were also analyzed in E2 (190 nt) and NS5B gene (409 nt) regions. Phylogenetic analysis revealed that all the 16 CSFV isolates analyzed belonged to group 1 and subgroup 1.1 in contrast to the situation in other Asian countries. Additionally, analysis in E2 and NS5B region placed the Indian isolates in a clearly separated clade within subgroup 1.1. The results suggest that subgroup 1.1 CSF viruses are currently circulating in India, which is important for epidemiology and control of CSF. 相似文献
20.
猪瘟病毒贵州流行株E2基因原核表达及其免疫原性的研究 总被引：4，自引：1，他引：3
本研究根据GenBank登录的猪瘟病毒Shimen和C株的E2基因序列设计1对特异引物,采集来自贵州的疑似猪瘟病死猪组织,提取总RNA,进行RT-PCR扩增,将扩增产物测序后进行核苷酸序列比较分析.并将RTPCR产物克隆到pMD18-T载体上,构建重组质粒pMD18-T-E2,经双酶切鉴定、核苷酸序列分析后,将E2基因亚克隆到pET-32a(+)原核表达载体上,成功构建猪瘟病毒E2基因原核表达质粒pET-32a-E2,将构建好的原核表达质粒pET-32a-E2转化至宿主菌BL21中,诱导表达目的蛋白,表达产物经SDS-PAGE电泳、Western blot分析,得到了约58 ku的条带,与预期大小相符,进一步提取、纯化目的蛋白,将目的蛋白加入弗氏佐剂免疫小鼠,免疫后采血检测抗体,结果显示目的蛋白能诱导小鼠产生一定抗体水平,该研究为猪瘟亚单位疫苗的研究奠定了基础. 相似文献