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1.
A serological survey was conducted in apparently healthy, unvaccinated indigenous Tswana goats and sheep in Kasane, Maun and Shakawe districts in northwestern Botswana in order to determine in these animals, the levels of exposure to the South African Territories (SAT) serotypes: SAT 1, SAT 2 and SAT 3 of foot-and-mouth disease virus (FMDV). A total of 250, 142 and 134 goat sera originating respectively from Kasane, Maun and Shakawe districts were tested for FMDV antibodies against the three SAT serotypes by the liquid phase blocking enzyme-linked immunosorbent assay and 26 of 250 (10.4%), 5 of 142 (3.5%) and 18 of 134 (13.4%) were positive either to SAT 1 or SAT 3, or to both serotypes. None of the goats' sera was positive to SAT 2 serotype. All sheep sera (n = 9) tested negative against all three serotypes of the virus. The findings are discussed in relation to results of other serological surveys carried out elsewhere.  相似文献   

2.
The study was conducted in three regional states of Ethiopia: Amhara, Oromia, and Addis Ababa from August 2008 to April 2009 with the objectives of identifying the genetic diversity of serotypes and topotypes in Ethiopia, and determining the attack rate and associations of potential risk factors with foot-and-mouth disease (FMD) seropositivity. A total of 496 cattle were clinically and serologically examined for presence of specific lesions and nonstructural protein for FMD, respectively. Of which, 140 (28.2%) manifested clinical signs and lesions suggestive of FMD, and 219 (44.2%) were seropositive. From a total of 7,781 animals observed and recorded on a designed format in six districts, 1,409 (19.6%) were infected, and 15 (0.12%) died during outbreaks of FMD. Epidemiological investigations revealed that the morbidity rate of the disease was 21.1% in Akaki-kality sub-city, but the mortality rate was <2% in all districts. Furthermore, the mortality and case fatality rates were relatively higher, 1.6% and 8.9% in calves than the other age groups, respectively. From a total of 33 bovine epithelial tissue-cultured samples, 19 (57.6%) showed CPE for FMD virus, in which 16 samples had serotype O and EA-3 topotype, while three samples had found serotype A, Africa topotype, and G-VII strain. Various strains of FMD viruses were isolated in Ethiopia in this study, and therefore, further detailed studies on the evaluation of available vaccines and the development of a vaccine which contains cocktails of antigens of FMD virus strains in the country should be encouraged.  相似文献   

3.
4.
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   

5.
针对编码非结构蛋白的3D基因合成一对引物进行口蹄疫病毒RT-PCR扩增,不同血清型病毒的RNA样本均显现一条457bp的目的带,与预期设计的长度相符合。在敏感性试验中,O型、A型和AsiaⅠ型病毒的最小RNA检出量分别为0.8ng、8ng和8ng。根据GenBank发表的口蹄疫病毒VP1和2A基因序列,采用多重RT-PCR鉴别口蹄疫病毒血清型,O型、A型和AsiaⅠ型病毒的特异性扩增片段分别为200bp、340bp和500bp。对9份乳鼠感染病料进行检测,确诊为O血清型口蹄疫病毒感染。  相似文献   

6.
7.
Analysis of synonymous codon usage in foot-and-mouth disease virus   总被引:1,自引:1,他引:0  
In this study, we calculate the relative synonymous codon usage (RSCU) values and codon usage bias (CUB) values to carry out a comparative analysis of codon usage pattern for open reading frames (ORFs) among 85 samples which belong to all seven serotypes of foot-and-mouth disease virus (FMDV). Although the degree of CUB for ORFs is a relatively slight, there is a significant variation for CUB among different serotypes, which is mainly determined by codon usage pattern depending on RSCU. By comparison with RSCU values for all samples, although RSCU values fail to show the relationship of specific-lineage serotype, there are two main genetic populations existing in FMDV, namely (i) serotypes Asia 1, A, C &O; (ii) serotypes SAT 1, 2 & 3. This interesting characteristic may be formed by the mechanism of RNA virus recombination. The analysis of quantitative & qualitative evaluation based on CUB indicates interesting characteristic of codon usage, which suggests that more FMDV genome diversity may exist in specific-lineage serotypes rather than exist randomly. Furthermore, the relationship between amino acids and codon usage pattern indicates that mutation pressure rather than translational selection in nature is the important determinant of the codon usage bias observed. Our work might give some sight into some characteristics of FMDV ORF and some evolutionary information of this virus.  相似文献   

8.
The mucosal immune response to foot-and-mouth disease virus (FMDV) type Asia 1 was examined in experimentally infected cattle by assaying antibodies by the virus-neutralizing test (VNT) and IgA ELISA in two secretory fluids, oesophageal pharyngeal fluid (OPF) and oro-nasal fluid (ONF). Out of 17 animals infected by the intradermo-lingual route, 12 became persistently infected (carriers), as defined by positive antigen capture RT-PCR reactions for FMDV RNA in OPF samples collected at 28 days or later after exposure. This proportion of carriers (71%) with FMDV Asia 1 is comparable to other serotypes of the virus. When the two groups were examined, the carriers and non-carriers showed no difference in the serum antibody titre until the end of the experiment at 182 days post-infection (DPI). However, despite an initial similarity significantly higher neutralizing antibody titres and FMDV-specific IgA response were detected among the carriers than the non-carriers in both of the secretory fluids. The response was higher and more stable in ONF compared to OPF. Thus, mucosal antibody assays have the potential to be used as a means of differentiating carrier from non-carrier cattle. Furthermore, the findings are consistent with the higher mucosal antibody response in carriers being an effect of persistent infection rather than the cause.  相似文献   

9.
A novel proximity ligation assay (PLA) using a pan-serotype reactive monoclonal antibody was developed and evaluated for the detection of foot-and-mouth disease virus (FMDV) in clinical samples collected from field cases of disease. The FMDV-specific PLA was found to be 100 times more sensitive for virus detection than the commonly used antigen capture-ELISA (AgELISA). As few as five TCID50 were detected in individual assays, which was comparable with the analytical sensitivity of real-time RT-PCR. Although this assay was capable of detecting diverse isolates from all seven FMDV serotypes, the diagnostic sensitivity of the PLA assay was lower than real-time RT-PCR mainly due to a failure to detect some SAT 1, SAT 2 and SAT 3 FMDV strains. In conclusion, this new PLA format has high analytical sensitivity for the detection of FMDV in clinical samples and may prove valuable as a rapid and simple tool for use in FMD diagnosis.  相似文献   

10.
The epidemiology of serotype SAT-2 foot-and-mouth disease was investigated in sub-Saharan Africa by phylogenetic analysis using the 1D gene encoding the major antigenic determinant. Fourteen genotypes were identified of which three are novel and belong to East Africa, bringing the total number of genotypes for that region to eight. The genotypes clustered into three lineages that demonstrated surprising links between East, southern and south-western Africa. One lineage was unique to West Africa. These results established numerous incursions across country borders in East Africa and long term conservation of sequences for periods up to 41 years. Ethiopia, Kenya and Uganda have all experienced outbreaks from more than one unrelated strain, demonstrating the potential for new introductions. The amount of variation observed within this serotype nearly equalled that which was found between serotypes; this has severe implications for disease control using vaccination.  相似文献   

11.
根据口蹄疫病毒VP1基因序列,利用Primer Premier 5.0软件设计4条特异性引物,通过对退火温度等反应条件进行优化,建立能够同时扩增出O型、A型、Asia-1型口蹄疫病毒的多重RT-PCR检测方法。结果表明,建立的方法最低可以检测出约含1 pg/μL的病毒样品;该方法对猪瘟病毒、猪细小病毒、猪伪狂犬病毒、猪繁殖与呼吸综合征病毒、猪圆环病毒等其他相关病毒的检测结果均为阴性,特异性良好。建立的方法能够对口蹄疫O型、A型、Asia-1型病毒准确定型,可广泛用于口蹄疫病毒3个血清型的快速检测和分子流行病学调查。  相似文献   

12.
A single step RT-PCR was tested for detection of foot and mouth disease virus (FMDV) and immunoenzymatic determination of amplified products in a microplate hybridization assay. Inactivated reference strains (ELISA antigen) of all seven serotypes were used to optimize the test. Oligonucleotide primers were selected from two different genomic regions coding for RNA polymerase and VP1 protein, respectively. The RT-PCR used to amplify the polymerase gene specific RNA detected FMDV strains A, C, O, Asial and SAT1, and the identity of the fragments obtained was confirmed with a specific internal biotin-labelled capture probe. For the amplification of the VP1 genome region, two sets of oligonucleotide primers were used. One primer pair was successfully applied for the detection of serotypes A, C, O and Asial and a second one for serotypes SAT1, SAT2, SAT3. The specific probe enabled the detection of all the amplified products in a PCR ELISA test. By comparison with antigen ELISA, the PCR ELISA method allowed the detection of smaller amounts of FMDV in the inactivated material examined. The application of molecular diagnostic methods to inactivated antigens offers a good alternative procedure for developing and optimizing a sensitive method for detection of FMDV in laboratories that are not allowed to work with viable FMDV.  相似文献   

13.
FMDV infection can cause a long lasting virus carrier state in the oesophageal-pharyngeal (OP) region of cattle, sheep, goats, African buffalo, wildebeest and kudu. Virus can be recovered from OP fluids with low titres for several months up to more than 2 years. During this time phases of positive virus recovery are interrupted by negative phases. The number of virus carriers decreases as time progresses. The virus carrier state is always accompanied by FMDV antibodies in serum and OP fluid. Vaccinated animals also become virus carriers after FMDV infection, to the same extent as unvaccinated animals. No virus carrier state has been proven in pigs, but it cannot be excluded in some species of deer. Epizootic importance of carrier animals (in FMD) has not been found. Experimental contact transmissions of carrier virus to cattle, sheep and goats have failed. Only buffalo transmit carrier virus to the own species and perhaps to cattle. Nevertheless, virus carriers represent a natural reservoir of FMDV in infected areas and a potential source of antigenically altered virus variants, since continuous variations of the virus and selection of virus mutants take place in the animal during the carrier state.  相似文献   

14.
A study to estimate the seroprevalence of Contagious Caprine Pluropneumonia (CCPP) in southern Ethiopia was conducted from November 2005 to June 2006. Two districts from sedentary (Arbaminch and Boreda) and pastoral (Hammar and Bena-Tsemay) production systems were included in the study. Sera samples were collected from 913 goats (234 from sedentary and 679 from pastoral) to check for CCPP serostatus. The animals were sampled from 155 flocks (44 pastoral and 111 sedentary). Five clinically suspected CCPP cases were also sacrificed and attempt was made to isolate Mycoplasma capricolum capripneumoniae (MccP) from lung tissue, nasal swab and plural exudates. Sera samples were tested for the presence of CCPP antibodies using CFT. The overall seroprevalence recorded in the study was 18.61%. The corresponding seroprevalences for sedentary and pastoral production systems were 27.78% and 15.46% respectively. Regarding districts, the prevalence in Hammar was 15.63% while that of Bena-Tsemay 15.29%. In Arbaminch and Boreda the percent of seroreactors were 23.01 and 32.23% respectively. Out of 44 pastoral and 111 sedentary flocks, 50.45% of pastoral and 65.91% of sedentary flocks had at least one seroreactor goat per flock respectively. Both in the univariable and multivariable logistic regression analysis, seropositivity was found to have strong association with sedentary production system (P < 0.05, OR = 2.24) and adult age (P < 0.05, OR = 1.77). In microbiological study, two broth cultures from thoracic fluid and two broth cultures from lung tissue samples were found to be positive for Mycoplasma capricolum capripneumoniae (MccP). In conclusion, both the serological study and bacteriological isolation confirmed the disease CCPP being an important disease that demands serious attention in both production systems.  相似文献   

15.
Tongue epithelia infected with each of the 7 serotypes of foot-and-mouth disease virus (FMDV) were used to evaluate in vivo and in vitro systems for the detection of FMDV. Cattle inoculated by the intradermal route in the tongue (IDL) and suckling mice inoculated intraperitoneally were compared for susceptibility to FMDV with freshly prepared bovine thyroid cell cultures; cultures from cryopreserved bovine thyroid, bone marrow, mammary gland, myocardium, tongue, ovary and kidney cells; cultures from cryopreserved embryonic ovine kidney, newborn ovine kidney, ovine testicle, bone marrow, and chloroid plexus cells; and the continuous porcine kidney cell lines MVPK-1 and S6. The mean titers determined for each serotype in each system were statistically compared. The FMDV titers obtained in freshly prepared bovine thyroid cell cultures and by cattle IDL inoculation were the highest and were statistically indistinguishable. The titers obtained by suckling mouse inoculation were significantly lower than the titers obtained in thyroid cultures for serotypes A, C, Asia 1, and SAT 3. The cattle IDL assay was significantly more sensitive than the mouse assay for serotype A. The cell cultures from the cryopreserved newborn ovine kidney and embryonic ovine kidney were significantly less susceptible to serotype Asia 1 when compared with the fresh bovine thyroid cultures, but not significantly different when compared with the cattle assay for all serotypes. Cryopreservation of bovine thyroid cells directly after trypsinization resulted in the loss of susceptibility to FMDV serotype SAT 2. The other cryopreserved cell culture systems exhibited no or minimal susceptibility to all 7 serotypes, or exhibited considerable inconsistency. The established cell lines MVPK-1 and S6 were not susceptible to serotype A, and were less sensitive to serotype C than other culture systems. Quality control of cell cultures used to evaluate field specimens for FMDV was critical. The cell cultures of cryopreserved ovine kidney cells provided the most practical diagnostic system.  相似文献   

16.
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   

17.
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   

18.
应用荧光RT-PCR检测亚欧型口蹄疫病毒   总被引:1,自引:0,他引:1  
根据口蹄疫病毒基因组的5’非翻译区序列比较保守的特点,采用软件设计亚欧型(A、O、C及Asia-1型)FMDV通用的引物和探针,经对反应条件和反应体系进行优化,建立了亚欧型FMDV的实时荧光RT-PCR检测方法。研究表明,该方法检测阳性质粒模板的线性范围为1.9×107-1.9×10拷贝,最低可检测19个拷贝。通过对FMDV各血清型(A、O、C、Asia-1及SAT-1,2,3型)的检测,证实该方法对亚欧型FMDV具有良好的特异性,能有效区分亚欧型和南非型FMDV感染。本研究为亚欧型口蹄疫的快速诊断和流行病学调查提供了新的方法。  相似文献   

19.

Foot-and-mouth disease (FMD) is a highly contagious and transboundary viral disease of domesticated and wild cloven-hoofed animals. The present study summarizes the knowledge generated from the epidemiology, diagnosis, and surveillance of the disease in the Maghreb (2014–2015) in assessing its threat to southern European countries. Currently, two serotypes of the FMD virus (O and SAT-2) and four lineages are circulating in the Maghreb region. The introduction of serotype SAT-2 in Libya and Mauritania in 2012 and 2015 respectively sets their neighbors and subsequently south European countries at constant risk of FMD re-emergence. The potential pathways of FMD introduction to southern European countries from the Maghreb are the illegal introduction of infected animals and animal products, particularly meat or meat products carried by refugees.

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20.
The present study was undertaken to determine the prevalence and distribution of Salmonella from apparently healthy slaughtered camels in Eastern Ethiopia. A total of 714 samples (faeces, mesenteric, lymph nodes, spleen, liver, abdominal and diaphragmatic muscles) from 119 slaughtered camels were analysed. Salmonellae were detected from 116 (16.2%) of the 714 samples examined. Eighteen (15.1%) faeces, 19 (15.9%) mesenteric lymph nodes, 14 (11.8%) livers and 17 (14.3%) spleen samples (n = 119 for each) were positive for Salmonella. Salmonellae were found in 20.1% of the abdominal and diaphragmatic muscles. A total of sixteen different serotypes were identified of which Salmonella saintpaul (38.8%) and S. braenderup (22.4%) were the most prevalent followed by S. muenchen (8.6%), S. kottbus (6.0%) and S. havana (5.2%). Other serotypes, including S. typhimurium, S. heidelberg and S. enteritidis were also detected from Ethiopian camels.  相似文献   

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