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1.
Foot-and-mouth disease is an endemic animal disease in Hong Kong. In this study, a total of 70 clinical specimens were collected from locally infected pigs from 2001 to 2010. Phylogenetic analysis of VP1 sequences reveal that all Hong Kong FMDV serotype O isolates are classified into three lineages: HK-A and HK-B in Cathay topotype, and HK-C in SEA topotype. Regression analysis projects that the time of divergence from the most recent common ancestor of HK-A and HK-B are 1964 ± 12 and 1987 ± 9 years respectively. Although HK-B shares a common ancestor with strains that caused outbreak in Taiwan and Philippines, there is no consolidated evidence demonstrating the order of introduction events among these regions. HK-C lineage is the latest FMDV isolated in Hong Kong. This virus is likely adopted from bovine into porcine. As local pigs confer immunity mainly against Cathay topotype viruses, introduction of HK-C viruses have led into an unexpectedly high severity and rapid spreading rate of the disease. A systematic surveillance and communication network is essential to provide accurate information in controlling the pandemics.  相似文献   

2.
口蹄疫是由口蹄疫病毒引起的主要侵袭偶蹄动物的一种急性热性高度接触性传染病。口蹄疫病毒为微RNA病毒科口蹄疫病毒属成员,存在7个不同血清型,病毒VP1蛋白抗原性差异是病毒血清型划分依据,而其编码基因(1D)核苷酸序列差异是同型病毒拓扑型(Topotype)或基因型鉴别依据。采用O/A/C/Asia-1多重RT-PCR技术,对2006年自云南边境地区采集的120份动物组织样品,进行口蹄疫病原监测,检出O型口蹄疫病毒阳性样品15份。对阳性样品中病毒VP1基因全序列进行扩增、纯化后,克隆至pMD18-T载体测序,并与已知代表性毒株进行比对及系统发育分析。结果发现:云南边境O型口蹄疫病毒阳性样品VP1基因核苷酸序列同源性介于77.3%~98.7%,可划分为3个不同的拓扑型或基因型:中东-南亚型(ME-SA)或泛亚型(PAN-Asia)、古典中国型(Cathay)、东南亚型(SEA)。部分样品VP1蛋白表位43位、154位关键性氨基酸位点存在变异。  相似文献   

3.
The nucleotide sequence of the protein-coding region of foot-mouth-disease virus (FMDV) strain O/HK/2001 was determined and compared with the sequences of other FMDVs that were registered in GenBank. The protein-coding region was 6966 nucleotides in length and encoded a protein of 2322 amino acid residues. Comparison of the nucleotide sequence and its deduced amino acid sequence with those of other isolates indicated that O/HK/2001 belonged to the Cathay topotype. A genomic coding region nucleotide sequence phylogenetic tree of several FMDV-O isolates showed that O/HK/2001 was most closely related to FMDV isolates found in Taiwan during 1997, and especially shared significant similarity to HKN/2002, suggesting that the virus causing outbreaks in Hong Kong was genetically most-closely related to that causing an outbreak of type O in Taiwan. Mutations in O/HK/2001 were revealed, including frequent substitutions in the VP1 and L proteins, and deletions involving 10 amino acid residues in the 3A protein. This study was undertaken to assess the regional variation of prevalent FMDV type O viruses and to establish a sequence database for FMDV molecular epidemiological investigation.  相似文献   

4.
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5.
Sequence diversity was assessed of the complete VP1 gene directly amplified from 49 clinical specimens during an explosive foot-and-mouth disease (FMD) outbreak in Taiwan. Type O Taiwan FMD viruses are genetically highly homogenous, as seen by the minute divergence of 0.2-0.9% revealed in 20 variants. The O/HCP-0314/TW/97 and O/TCP-022/TW/97 viral variants dominated FMD outbreaks and were prevalent in most affected pig-raising areas. Comparison of deduced amino acid sequences around the main neutralizable antigenic sites on the VP1 polypeptide showed no significant antigenic variation. However, the O/CHP-158/TW/97 variant had an alternative critical residue at position 43 in antigenic site 3, which may be due to selective pressure in the field. Two vaccine production strains (O1/Manisa/Turkey/69 and O1/Campos/Brazil/71) probably provide partial heterologous protection of swine against O Taiwan viruses. The type O Taiwan variants clustered in sublineage A1 of four main lineages in the phylogenetic tree. The O/Hong Kong/9/94 and O/1685/Moscow/Russia/95 viruses in sublineage A2 are closely related to the O Taiwan variants. The causative agent for the 1997 epidemic presumably originated from a single common source of type O FMD viruses prevalent in neighboring areas.  相似文献   

6.
以3株国内分离的O型口蹄疫病毒(FMDV)(分别命名F1、F2、F3)为研究目标,根据GenBank中注册的FMDV VP1基因的序列设计2对引物,采用RT-PCR方法成功地扩增出含有VP1全基因的cD-NA片段,将3个cDNA片段分别克隆到pMD20-T Vector载体中进行序列测定,得到3个毒株VP1基因的序列。结果表明,3个O型FMDV毒株VP1基因cDNA长度均为639 bp,编码213个氨基酸。3株O型毒株彼此之间的核苷酸序列同源性在92.3%~94.2%之间,推导氨基酸序列同源性在97.2%~98.6%之间。与3个毒株同源性高的主要为香港和台湾的毒株。  相似文献   

7.
Most isolates of foot-and-mouth disease virus (FMDV) display a broad host range. Since the late 1990s, the genetic lineage of PanAsia topotype FMDV serotype O has caused epidemics in the Far East, Africa, the United Kingdom, France, the Netherlands, and numerous other countries throughout Europe and Asia. In contrast, there are several FMDV isolates that exhibit a more restricted host range. A Cathay topotype isolate of FMDV serotype O from the 1997 epizootic in Taiwan (O/TAW/97) demonstrated restricted host specificity, only infecting swine. Methods used to evaluate infectivity and pathogenicity of FMDV isolates in cattle are well-documented, but there has been less progress studying transmission and pathogenicity of FMDV isolates in pigs. In previous studies designed to examine pathogenicity, various chimeric viruses derived from O/TAW/97 were intradermally inoculated in the heel bulb of pigs. Subsequent quantitative scoring of disease and evaluation of virus released into nasal secretions and blood was assessed. Here we prove the usefulness of this method in direct and contact inoculated pigs to evaluate infectivity, pathogenicity and transmission of different Asian FMDV isolates. Virus strains within the Cathay topotype were highly virulent in swine producing a synchronous disease in inoculated animals and were efficiently spread to in-contact naive pigs, while virus strains from the PanAsia topotype displayed more heterogeneous properties.  相似文献   

8.
从GenBank和世界口蹄疫参考实验室基因库(WRLFMD)下载O型FMDV全VP1序列共210条,其中23条为已知基因型序列,其他为未知基因型序列.利用分子生物学软件DNA Star中的ClustalW和TreeView工具,以已知基因型的VP1区序列构建系统发育树,验证分型结果与已知基因型是否一致.然后以已知基因型序列作为参照,将未知基因型序列与已知基因型序列一起构建系统发育树,以已知基因型序列在系统发育树中所处的位置,来判断未知基因型序列的归属,从而明确它们归属于何种基因型.结果表明,采用此种分型方法获得Cathay型74条、SEA型24条、EA型4条、WA型4条、Euro-SA型21条、ME-SA型68条、ISA-1型3条、ISA-2型2条,未能分型序列10条.  相似文献   

9.
Foot-and-mouth disease virus (FMDV) is a highly contagious and genetically variable virus. Sporadic introductions of this virus into FMD-free countries may cause outbreaks with devastating consequences. In 2010 and 2011, incursions of the FMDV O/SEA/Mya-98 strain, normally restricted to countries in mainland Southeast Asia, caused extensive outbreaks across East Asia. In this study, 12 full genome FMDV sequences for representative samples collected from the People’s Republic of China (PR China) including the Hong Kong Special Administrative Region (SAR), the Republic of Korea, the Democratic People’s Republic of Korea, Japan, Mongolia and The Russian Federation were generated and compared with additional contemporary sequences from viruses within this lineage. These complete genomes were 8119 to 8193 nucleotides in length and differed at 1181 sites, sharing a nucleotide identity ≥ 91.0% and an amino acid identity ≥ 96.6%. An unexpected deletion of 70 nucleotides within the 5′-untranslated region which resulted in a shorter predicted RNA stem-loop for the S-fragment was revealed in two sequences from PR China and Hong Kong SAR and five additional related samples from the region. Statistical parsimony and Bayesian phylogenetic analysis provide evidence that these outbreaks in East Asia were generated by two independent introductions of the O/SEA/Mya-98 lineage sometime between August 2008 and March 2010. The rapid emergence of these viruses from Southeast Asia highlights the importance of adopting approaches to closely monitor the spread of this lineage that now poses a threat to livestock industries in other regions.  相似文献   

10.
Epitope-based vaccines are always questioned for their cross-protection against the antigenically variable foot-and-mouth disease virus (FMDV). In this study, we proved the cross-protection effect of a multi-epitope vaccine incorporated with poly(I:C) against three topotypes of O type FMDV. A total of 45 naïve pigs were vaccinated with different doses of multi-epitope protein vaccine incorporated with poly(I:C). At 28 days post-vaccination, 45 vaccinated and 6 unvaccinated control pigs (two pigs for each group) were challenged with three topotypes of virulent O type FMDV, namely, O/Mya/98 (Southeast Asia topotype), O/HN/CHA/93 (Cathay topotype) and O/Tibet/CHA/99 (PanAsia topotype) strains. All unvaccinated pigs developed generalised FMD clinical signs. Results showed that all pigs (n = 15) conferred complete protection against the O/Mya/98 and O/HN/CHA/93 FMDV strains, 11 of which were protected against the O/Tibet/CHA/99 FMDV strain. The 50% protective dose values of the vaccine against the O/Mya/98, O/HN/CHA/93 and O/Tibet/CHA/99 FMDV strains were 15.59, 15.59 and 7.05, respectively. Contact challenge experiment showed that transmission occurred from the donors to the unvaccinated but not to vaccinated pigs. These results showed that vaccination with multi-epitope protein vaccine incorporated with poly(I:C) can efficiently prevent FMD in pigs.  相似文献   

11.
口蹄疫病毒能引起牛、羊等偶蹄动物发生高度接触性的传染病口蹄疲,该病常常影响着全球畜牧业的发展.FMDV是小RNA病毒科口蹄疫病毒属的成员,口蹄疫病毒为单股正链RNA病毒,病毒基因组全长约8.5 kb,基因组分为5'非编码区、3'非编码区和一个开放阅读框(ORF).基因组的中部是一大的开放阅读框,编码一多聚蛋白,多聚蛋白在翻译的同时,经二级裂解后,形成3种病毒结构蛋白(VP0,VP3和VP1)和8种非结构蛋白(L,2A,2B,2C,3A,3B,3C和3D).其中3C全长639 bp,编码213个氨基酸.3C蛋白酶是小RNA病毒的共同裂解酶,在多聚蛋白成熟过程中起着极为重要的作用,且在抗病毒药物打靶方面具有一定研究价值.因此,对3C蛋白酶的结构及功能研究进展进行综述很有必要.  相似文献   

12.
At present, Foot-and-Mouth Disease (FMD) has been successfully controlled in most territories of South America, where only Ecuador and Venezuela remain as endemic countries. In this context, the precise characterization of circulating viruses is of utmost importance. This work describes the first molecular epidemiology study performed with the complete VP(1)-coding region of 114 field isolates of FMD virus (FMDV) type O, collected in the Andean countries mainly during 2002-2008. Sequences were aligned and compared to isolates responsible for emergencies in the Southern Cone of the continent between the years 2000 and 2006, and to other representative type O viruses worldwide. The results showed that FMD type O viruses isolated in South America and analyzed up to date are placed in 11 different lineages within the Euro SA topotype. Five of these lineages included viruses circulating in Ecuador and Venezuela during 2002-2008. The last emergencies reported in already-free areas in the Andean region, showed close relationships with viruses circulating in these endemic countries. Andean lineages showed a clear separation from the unique lineage containing viruses responsible for the emergencies in the Southern Cone, reflecting the different livestock circuits and providing evidence that support the ecosystem dynamics in the region. A wide geographical dissemination of the same strain in short time intervals has been observed, pointing to animal movements as the most significant risk parameter. This fact, together with an important generation of viral variants in areas under weak control strategies, reinforce the need of stronger official controls, as well as for establishing multinational cooperative measures in the border areas.  相似文献   

13.
Foot-and-mouth disease (FMD) is a highly contagious disease that afflicts cloven-hoofed animals. The etiological agent of FMD is foot-and-mouth disease virus (FMDV). The VP1 gene of FMDV is essential during the life cycle of the virus and plays a key role in the attachment of the virus to susceptible cells. We constructed a plasmid, pCWN11, that expresses siRNAs multiple-targeting the VP1 genes of FMDV. We evaluated the gene silencing efficiency of the plasmid using an enhanced green fluorescent protein (EGFP) reporter system in BHK-21 cells. The antiviral potential of the plasmid in BHK-21 cells and suckling mice were investigated. The results indicate that cotransfection of pCWN11 with any one of three serotypes VP1-EGFP plasmids resulted in a reduction in the EGFP signal relative to the control. Moreover, the antiviral potential induced by pCWN11 was evident during challenge with one FMDV isolate of either serotype O (HKN/2002) or serotype Asia I (YNBS/58), and the inhibition extended to almost 40 h. Furthermore, subcutaneous injection of pCWN11 in the neck made suckling mice significantly less susceptible to FMDV serotype O and Asia I.  相似文献   

14.
Peste des petits ruminants (PPR) and foot-and-mouth disease (FMD) are both highly contagious diseases of small domestic and wild ruminants caused by the PPR virus (PPRV) and the FMD virus (FMDV). In this study, a recombinant PPRV expressing the FMDV VP1 gene (rPPRV/VP1) was generated and FMDV VP1 expression did not impair replication of the recombinant virus in vitro and immunogenicity in inducing neutralizing antibody against PPR in goats. Vaccination with one dose of rPPRV/VP1 induced FMDV neutralizing antibody in goats and protected them from challenge with virulent FMDV. Our results suggest that the recombinant PPRV expressing the FMDV VP1 protein is a potential dual live vectored vaccine against PPRV and FMDV.  相似文献   

15.
根据GenBank中O型和Asia1型口蹄疫病毒(Foot-and-mouth disease virus,FMDV)的vp3、vp1和2A基因序列,并与其它血清型FMDV的对应基因序列进行比较,设计用于扩增O型和Asia1型FMDV vp1基因的特异性引物,建立O型和Asia1型FMDV RT-PCR鉴别诊断方法。本方法首先用通用型引物进行RT-PCR,确定是否为FMDV感染,然后用特异性引物鉴别O型或Asia1型FMDV的感染。用vp1基因序列分析进行符合性试验,验证了该方法所具有的特异性和敏感性。本方法可用于O型和Asia1型FMD的快速诊断及流行病学调查。  相似文献   

16.
Foot-and-mouth disease virus (FMDV) causes a highly contagious infection in cloven-hoofed animals. The format of FMD virus-like particles (VLP) as a non-replicating particulate vaccine candidate is a promising alternative to conventional inactivated FMDV vaccines. In this study, we explored a prokaryotic system to express and assemble the FMD VLP and validated the potential of VLP as an FMDV vaccine candidate. VLP composed entirely of FMDV (Asia1/Jiangsu/China/2005) capsid proteins (VP0, VP1 and VP3) were simultaneously produced as SUMO fusion proteins by an improved SUMO fusion protein system in E. coli. Proteolytic removal of the SUMO moiety from the fusion proteins resulted in the assembly of VLP with size and shape resembling the authentic FMDV. Immunization of guinea pigs, swine and cattle with FMD VLP by intramuscular inoculation stimulated the FMDV-specific antibody response, neutralizing antibody response, T-cell proliferation response and secretion of cytokine IFN-γ. In addition, immunization with one dose of the VLP resulted in complete protection of these animals from homologous FMDV challenge. The 50% protection dose (PD50) of FMD VLP in cattle is up to 6.34. These results suggest that FMD VLP expressed in E. coli are an effective vaccine in guinea pigs, swine and cattle and support further development of these VLP as a vaccine candidate for protection against FMDV.  相似文献   

17.
Genetic variation of foot-and-mouth disease virus (FMDV) isolates, serotype O, recovered serially over a 1-year period from persistently infected buffalos was assessed. The persistent state was established experimentally with plaque-purified FMDV, strain O(1)Campos, in five buffalos (Bubalus bubalis). Viral isolates collected from esophageal-pharyngeal (EP) fluids for up to 71 weeks after infection were analyzed at different times by nucleotide sequencing and T(1) RNase oligonucleotide fingerprinting to assess variability in the VP1-coding region and in the complete genome, respectively. Genetic variation increased, although irregularly, with time after infection. The highest values observed for the VP1-coding region and for the whole genome were 2.5% and 1.8%, respectively. High rates of fixation of mutations were observed using both methodologies, reaching values of 0.65 substitutions per nucleotide per year (s/nt/y) and 0.44s/nt/y for nucleotide sequencing and oligonucleotide fingerprinting, respectively, when selected samples recovered at close time periods were analyzed. The data herein indicate that complex mixtures of genotypes may arise during FMDV type O persistent infection in water buffalos, which can act as viral reservoirs and also represent a potential source of viral variants. These results fit within the quasi-species dynamics described for FMDV, in which viral populations are constituted by related, non-identical genomes that evolve independently from each other, and may predominate at a given time.  相似文献   

18.
The O/Taiwan/99 foot-and-mouth disease virus (FMDV), a South Asian topotype of serotype O, was introduced into Taiwan in 1999. The Chinese yellow cattle infected by the virus did not develop clinical lesions under experimental and field conditions. A blocking enzyme-linked immunosorbent assay (ELISA) kit with the 3AB antigen, a polypeptide of FMDV non-structural (NS) proteins, was used to evaluate the development and duration of anti-3AB antibodies, proving active viral replication, in the Chinese yellow cattle. The specificity of the assay was 99%, as was established with negative sera from regularly vaccinated and from na?ve cattle. The sensitivity tested with sera from naturally infected animals was approximately 64% and it was lower than that obtained by serum neutralization (SN) test. Under experimental infection, the Chinese yellow cattle developed lower anti-3AB antibodies than that developed in other species. Duration of anti-3AB antibodies was traced in two herds of naturally infected animals, indicating that anti-3AB antibodies persisted for approximately 6 months after outbreaks. On the basis of this study, we propose that the Chinese yellow cattle may have natural resistance, which limits viral replication and reduces the development of anti-3AB antibodies.  相似文献   

19.
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20.
Monoclonal antibodies (MAbs) reported here were produced against the porcinophilic foot-and-mouth disease virus (FMDV) that caused the devastating swine disease on 1997 in Taiwan. A panel (25) of MAbs were found to react with VP1 of O/Taiwan/97 (O/97) by ELISA with various potencies. The biological identities of these VP1 reacting MAbs, such as neutralization activity, isotype and capability to distinguish between two serotype O FMDVs, O/97 and O/Taiwan/KM1/99 (O/99), were further analyzed. Eleven out of the total eighteen O/97 neutralizing MAbs were able to neutralize heterologous O/99. Eight O/97 neutralizing and five non-neutralizing MAbs could differentiate two serotype O FMDVs by immunofluorescence assay (IFA) implied that these thirteen MAbs recognized O/97 specific epitope(s). Furthermore, reactivities of the VP1 reacting MAbs with a 29 amino acids synthetic peptide (P29) representing the betaG-betaH loop of VP1 were analyzed by ELISA and fourteen were found positive. MAb clone Q10E-3 reacting strongest with VP1 and P29, neutralizing both but not differentiating two serotype O viruses suggested that the antibody binding site might involve the RGD motif and its C terminal conserved region on betaG-betaH loop. MAbs with diverse characters presented in this study were the first raised against porcinophilic FMDV. The complete set of MAbs may be used for further studies of vaccine, diagnostic methods, prophylaxis, etiological and immunological researches on FMDV.  相似文献   

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