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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.
Partial 1D gene characterization was used to study phylogenetic relationships between 17 serotype O foot-and-mouth disease (FMD) viruses in Ethiopia as well as with other O-type isolates from Eritrea, Kenya, South and West Africa, the Middle East, Asia and South America. A homologous region of 495 bp corresponding to the C-terminus end of the 1D gene was used for phylogenetic analysis. This study described three lineages, viz. African/Middle East-Asia, Cathay and South American. Within lineage I, three topotypes were defined, viz. East and West Africa and the Middle East-Asia together with the South African isolate. The Ethiopian isolates clustered as part of topotype I, the East African topotype. Two clades (based on < 12 % nucleotide difference) A and B were identified within the East African isolates, with clade A being further classified into three significant branches, A1 (80% bootstrap support), A2 (89% bootstrap support) and A3 (94% bootstrap support). Clade B consisted of two Kenyan isolates. Within topotype I, the 17 Ethiopian isolates showed genetic heterogeneity between themselves with sequence differences ranging from 4.6-14 %. Lineage 2 and 3 could be equated to two significant topotypes, viz. Cathay and South America. Comparison of amino acid variability at the immunodominant sites between the vaccine strain (ETH/19/77) and other Ethiopian outbreak isolates revealed variations within these sites. These results encourage further work towards the reassessment of the type O vaccine strain currently being used in Ethiopia to provide protection against field variants of the virus.  相似文献   

4.
In 1999, 10 sporadic outbreaks of cattle foot-and-mouth disease (FMD) occurred in Taiwan. By the time, infection was limited to the Chinese yellow cattle (a native species of beef cattle in Mainland China), which did not develop vesicular lesions under field conditions. Five viruses isolates obtained from individual farms were confirmed to be the serotype O FMD virus (O/Taiwan/1999). During January-February 2000, however, this virus has spread to dairy cattle and goat herds, causing severe mortality in goat kids and vesicular lesions in dairy cattle. Partial nucleotide sequence of the capsid coding gene 1D (VP1) was determined for the virus isolates obtained in this study. Phylogenetic analysis of the VP1 sequences indicated that the O/Taiwan/1999 viruses shared 95-97% similarities to the virus strains isolated from the Middle East and India. The species susceptibility of the O/Taiwan/1999 virus was experimentally studied in several species of susceptible animals, showing that the virus did cause generalized lesions in dairy cattle and pigs, however, it would not cause vesicular lesions on the Chinese yellow cattle and the adult goats. These studies suggested that the O/Taiwan/1999 virus was a novel FMD virus of Taiwan and it presented various levels of susceptibility in cattle species.  相似文献   

5.
[目的]为了及时掌握牛口蹄疫免疫后的免疫效果,为口蹄疫防控提供理论依据.[方法]张掖市动物疫病预防控制中心每年春秋两季集中免疫后对全市6县(区)送检的牛口蹄疫免疫血清开展了免疫抗体检测,为科学评价免疫效果提供了理论依据.[结果]2014-2020年,共检测牛O型口蹄疫免疫血清12 328份,抗体合格10 910份,平均...  相似文献   

6.
The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and the Southern Nations Nationalities and people regional state from August 2007 to April 2008 with the objective of identifying the foot and mouth disease virus (FMDV) serotypes circulating in the region. Two serotypes were recorded from epithelial tissue and oesophageal–pharyngeal (OP) fluid that were taken from outbreaks in study regions of Ethiopia. Serotype O FMDV was identified in Girar Jarso, Yabello, and Ankesha Guagusa districts while SAT-1 was isolated in Surma and Maji districts from tissue samples and this was the first report of the FMDV serotype in Ethiopia. Similarly, the OP fluid samples were found positive for SAT-1 FMDV in Maji and Surma districts.  相似文献   

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Serological investigation to detect foot-and-mouth disease (FMD) virus circulation in the domestic small ruminant population of India was conducted. A total of 4407 and 4035 serum samples from sheep and goats, respectively were collected at random covering majority of the states across the country during 2010–2012. These samples were analyzed for antibodies against the non-structural proteins (NSP) of FMD virus in an indirect 3AB NSP ELISA and against the structural proteins (SP) in a liquid phase blocking (LPB) ELISA. A total of 20.35% sheep and 13.60% goats were found to be positive for 3AB NSP antibodies providing a serological evidence of extensive viral activity. In LPB ELISA, only 4.54% sheep and 6.27% goats were found to have protective antibody (log10 titre of ≥1.8) against all three serotype strains in the vaccine, which correlates with “no or sparse vaccination” scenario in these species in the country. Hence, to check silent amplification and dissemination of virus in a mixed farming set up, small ruminants may be brought under the ambit of routine vaccination and surveillance programmes.  相似文献   

9.
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   

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.
PRRSV感染猪体内多杀性巴氏杆菌的分离与血清型鉴定   总被引:1,自引:0,他引:1  
应用常规方法和PCR技术,对来自安徽肥西、庐江、肥东、定远、桐城5个地区猪场检测为猪繁殖与呼吸综合征病毒(PRRSV)阳性的肺脏进行多杀性巴氏杆菌(Pm)的分离及其血清型鉴定。结果显示,49份病料中分离鉴定出7株Pm,且均属于A型,分离率为14.3%,高于其他细菌(副猪嗜血杆菌、猪链球菌)的检出率。表明猪繁殖与呼吸综合征(PRRS)患猪继发或混合感染Pm的比率较高,而且A型Pm是安徽省感染猪群中的主要血清型。  相似文献   

12.
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   

13.
Participatory epidemiology (PE) was used on the Borana plateau of southern Ethiopia to understand pastoralist’s perceptions of the clinical and epidemiological features of foot and mouth disease (FMD) in cattle. Matrix scoring showed good agreement between informant groups on the clinical signs of acute and chronic FMD, and findings were cross-checked by clinical examination of cattle and assessment of previous clinical FMD at herd level by detection of antibody to non structural proteins of FMD virus. The positive predictive value of pastoralist’s diagnosis of FMD at herd level was 93.1%. The annual age-specific incidence and mortality of acute FMD in 50 herds was estimated using proportional piling. The estimated mean incidence of acute FMD varied from in 18.5% in cattle less than two years of age to 14.0% in cattle three to four years of age. The estimated mean mortality due to acute FMD varied from 2.8% in cattle less than two years of age to 0.3% in cattle three of age or older. Pearson correlation coefficients for acute FMD by age group were −0.12 (p > 0.05) for incidence and −0.59 (p < 0.001) for mortality. Estimates of the annual incidence of chronic FMD varied from 0.2% in cattle less than two years of age to 1.8% in cattle three to four years of age. The Pearson correlation coefficient for the incidence of chronic FMD by age group was 0.47 (p < 0.001). Outbreaks of FMD peaked in Borana cattle during the two dry seasons and were attributed to increased cattle movement to dry season grazing areas. The mean seroprevalence of FMD was estimated at 21% (n = 920) and 55.2% of herds (n = 116) tested seropositive. Serotyping of 120 seropositive samples indicated serotypes O (99.2%), A (95.8%), SAT 2 (80%) and C (67.5%). The endemic nature of FMD in Borana pastoral herds is discussed in terms of the direct household-level impact of the disease, and the increasing export of cattle and chilled beef from Ethiopia.  相似文献   

14.
Foot-and-mouth disease (FMD) in South American camelids, in dromedaries and Bactrians is reviewed. Recent well-executed experimental studies in New World camels indicate that, although the llama and alpaca can be infected with FMD virus (FMDV) by direct contact, they are not very susceptible and do not pose a risk in transmitting FMD to susceptible animal species. They do not become FMDV carriers. Reports on FMD in dromedaries are, however, conflicting. Serological investigations in Africa and the United Arab Emirates (UAE) on thousands of camel sera were negative and experimental infections have been conducted on only a few dromedaries with one serotype and in one country. The design and execution of most of these experiments were poor and therefore the conclusions are questionable. From these investigations, it seems that dromedaries can contract the disease after experimental infection and through close contact with FMD diseased livestock, but do not present a risk in transmitting FMD to susceptible animals. They do not become FMDV carriers. Recent reports from Mongolia describe similar FMD lesions in Bactrian camels. However, so far no samples have tested positive for FMD. To clarify the situation in Bactrians, samples from suspected clinical cases should be tested because other viral vesicular diseases cannot be distinguished from FMD. Thus, further research on the epidemiology of FMD in camelids is necessary. This would include large-scale serological investigations and experimental infections with different FMD serotypes in connection with susceptible contact animals. The Office International des Epizooties (OIE) Code chapter on FMD includes camelids as being susceptible species to FMD, giving the impression that they are similar to cattle, sheep, goats and pigs in their potential involvement in the epidemiology of FMD. This is clearly not the case, and this issue should be re-addressed by the relevant authorities.  相似文献   

15.
In northern Pakistan, many farming communities rely on domestic yak (Bos grunniens) as a principle source of income. A 2006 participatory disease surveillance report from this region indicated that foot-and-mouth disease (FMD) is the most prevalent annual disease of yak. Our objectives of this study were to determine exposure levels of yak to FMD virus; implement a vaccination program based on current, regional FMD virus serotypes and subtypes; and quantify immune responses following vaccination. Blood samples were used to determine pre-vaccination exposure of animals to FMD virus by antibody presence to non-structural proteins of FMD virus using a 3-ABC trapping indirect ELISA. Vaccine used consisted of FMD serotypes ‘O’ (PanAsia-2), ‘A’ (Iran-05), and ‘Asia-1’ (Shamir), but changed later during the study to match newly circulating viruses in the country (‘O’-PanAsia-2; ‘A’-Turk-06 and Asia-1-Sindh-08). Three hundred sixty-three blood samples were tested from selected villages to determine pre-vaccination FMD virus exposure in yak with an average of 37.7%. Immune responses from initial vaccination and booster dose 30 days later showed clear protective levels (as mean percent inhibition) of antibodies against structural proteins of serotypes ‘O,’ ‘A,’ and ‘Asia-1.’ These responses remained above threshold positive level even at day 210 following initial vaccination. Results of sero-surveillance and anecdotal information of repeated FMD outbreaks demonstrate the persistence of FMD virus of yak in northern Pakistan. Laboratory results and field observations clearly indicated that yak can be protected against FMD with a good quality vaccine with FMD serotype(s) matching current, regionally circulating FMD virus.  相似文献   

16.
A retrospective study on the outbreaks of foot-and-mouth disease (FMD) in Bhutan, between the years 1996 and 2008, based on the data collected through passive surveillance, was undertaken. A total of 230 outbreaks of FMD at sub-district level were recorded in 299 villages located in 19 out of the 20 districts in the country. There were no significant differences between the years (P = 0.998) or months (P = 0.989) on the incidence of FMD. The sub-districts in the north (altitude >1,000 m above mean sea level) had significantly (P = 0.008) higher incidences of outbreaks in winter than in summer. The sub-districts that shared border with India had significantly more outbreaks than those that didn't (P = 0.001). Cattle were the most predominant species affected being involved in all of the outbreaks reported. Serotype O, which constituted 70.6% of the outbreaks typed was the most predominant serotype prevalent in Bhutan followed by A (16.7%), Asia 1 (8.8%), and C (3.9%). Cattle density was significantly positively correlated (P = 0.023) with the incidence of disease. Three waves of outbreaks of epidemic proportions were reported in 1997/1998, 2002/2003, and 2007/2008 due to the PanAsia strain of the O serotype. The study highlights the incursion of the PanAsia strain of the O serotype into the country, possibly, through the transboundary movement of animals and the need for active surveillance of FMD, especially at the border areas. The study also highlights the significance of the O serotype and cattle as the main indicator species in the epidemiology of FMD in Bhutan. The findings from this study can be used as baseline epidemiological data for further research to understand the epidemiology of FMD in Bhutan.  相似文献   

17.
This study reports on an outbreak of disease that occurred in central Algeria during July 2006. Sheep in the affected area presented clinical signs typical of bluetongue (BT) disease. A total of 5245 sheep in the affected region were considered to be susceptible, with 263 cases and thirty-six deaths. Bluetongue virus (BTV) serotype 1 was isolated and identified as the causative agent. Segments 2, 7 and 10 of this virus were sequenced and compared with other isolates from Morocco, Italy, Portugal and France showing that they all belong to a ‘western’ BTV group/topotype and collectively represent a western Mediterranean lineage of BTV-1.  相似文献   

18.
Foot-and-mouth disease (FMD) is endemic in Kenya and has been well studied in cattle, but not in pigs, yet the role of pigs is recognised in FMD-free areas. This study investigated the presence of antibodies against FMD virus (FMDV) in pigs sampled during a countrywide random survey for FMD in cattle coinciding with SAT 1 FMDV outbreaks in cattle. A total of 191 serum samples were collected from clinically healthy pigs in 17 districts. Forty-two of the 191 sera were from pigs vaccinated against serotypes O/A/SAT 2 FMDV. Antibodies against FMDV non-structural proteins were found in sera from 30 vaccinated and 71 non-vaccinated pigs, altogether 101/191 sera (53 %), and 91 % of these (92/101) also had antibodies measurable by serotype-specific ELISAs, predominantly directed against SAT 1 with titres of 10–320. However, only five high titres against SAT 1 in vaccinated pigs were confirmed by virus neutralisation test (VNT). Due to high degree of agreement between the two ELISAs, it was concluded that positive pigs had been infected with FMDV. Implications of these results for the role of pigs in the epidemiology of FMD in Kenya are discussed, and in-depth studies are recommended.  相似文献   

19.
The complete VP1 encoding (1D) gene of 54 foot-and-mouth disease (FMD) virus serotype Asia1 field isolates, most of which were isolated during 2000 and 2001, was sequenced. The phylogenetic analysis identified a novel subgroup (>10% nucleotide divergence) within the widely circulating lineage of this serotype. The newly emerged viruses were responsible for disease outbreaks in both cattle and buffaloes and were present in six different states in the country. Amino acid sequence comparison of these isolates revealed significant sequence divergence at many of the amino acid positions in comparison to those of lineage VI-A and C. Emergence of such viruses may affect the efficacy of vaccine strain currently used for protection against FMD in India.  相似文献   

20.
The results of a serological survey of livestock in Kazakhstan, carried out in 1997--1998, are reported. Serum samples from 958 animals (cattle, sheep and goats) were tested for antibodies to foot and mouth disease (FMD), bluetongue (BT), epizootic haemorrhagic disease (EHD), rinderpest (RP) and peste des petits ruminants (PPR) viruses, and to Brucella spp. We also investigated the vaccination status of livestock and related this to changes in veterinary provision since independence in 1991. For the 2 diseases under official surveillance (FMD and brucellosis) our results were similar to official data, although we found significantly higher brucellosis levels in 2 districts and widespread ignorance about FMD vaccination status. The seroprevalence for BT virus was 23%, and seropositive animals were widespread suggesting endemicity, despite the disease not having being previously reported. We found a few seropositives for EHDV and PPRV, which may suggest that these diseases are also present in Kazakhstan. An hierarchical model showed that seroprevalence to FMD and BT viruses were clustered at the farm/village level, rather than at a larger spatial scale. This was unexpected for FMD, which is subject to vaccination policies which vary at the raion (county) level.  相似文献   

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