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1.
分析2013—2019年中国西北部分省区不同基因亚型牛病毒性腹泻病毒（BVDV）抗原基因Erns的分子特征,了解其遗传演化规律。从甘肃、青海、宁夏规模化牛场送检的疑似牛病毒性腹泻发病牛150份EDTA抗凝血提取总RNA,利用RT-PCR扩增病毒基因组Erns-E1区,克隆测序后比对,构建系统进化树进行遗传演化关系分析。利用牛肾细胞MDBK对检出的不同基因亚型BVDV进行分离,并鉴定其生物型。RT-PCR扩增结果表明,BVDV总体阳性率为37.33%,其中甘肃省、青海省、宁夏回族自治区BVDV阳性率分别为37.68%、35.71%、40.00%。获得56份Erns-E1 DNA,克隆测序获得33条不同的Erns序列,长度均为681 bp,分析表明流行株分属10个BVDV基因亚型：BVDV-1a （2株）、BVDV-1b （5株）、BVDV-1c （1株）、BVDV-1d （3株）、BVDV-1m （11株）、BVDV-1o （1株）、BVDV-1p （4株）、BVDV-1q （4株）、BVDV-1v （1株）、BVDV-2a （1株）。分离获得BVDV-1a亚型、BVDV-1b亚型、BVDV-1v亚型、BVDV-2a亚型分离株各1株,BVDV-1 d亚型分离株2株,均为非致细胞病变型。各亚型株间Erns基因核苷酸相似性以BVDV-1a～1d经典亚型株（79.8%～85.9%）或1m～1q及1v新亚型株（81.0%～87.3%）较高,以BVDV-1 m和BVDV-1p流行株亚型间相似性最高（87.3%）。各亚型株Erns基因编码蛋白的RNA酶活性位点以及双链RNA作用基序（139KKGK142）保守,但Erns第26位糖基化位点（26 NRSL）在1m～1q、1v亚型株移位（24 NVSR）。首次以Erns核苷酸序列构建系统进化树,结果显示1m～1q及1v等亚型BVDV株在进化上关系较为密切。本研究首次选用Erns靶标基因对甘肃、青海、宁夏部分省区牛源BVDV株进行同源性及系统进化分析,发现10个基因亚型流行株,以1m亚型株最为普遍,1m～1q及1v等亚型株亲缘关系密切。  相似文献   

2.
Bovine viral diarrhea virus (BVDV) field isolates show genetic and antigenic diversity. At least 14 subgenotypes of BVDV-1 and 4 of BVDV-2 have been identified in Artiodactyla worldwide. Of these, 6 subgenotypes of BVDV-1 and 1 of BVDV-2 have been isolated in Japan. Previously, we reported that each subgenotype virus expresses different antigenic characteristics. Here we investigated the reactivity of neutralizing antibodies against representative strains of Japanese BVDV subgenotypes using sera from 266 beef cattle to estimate the prevalence of this epidemic virus among cattle in Japan. Antibody titers at concentrations at least 4-fold higher than antibodies against other subgenotype viruses were considered subgenotype specific. Subgenotype-specific antibodies were detected from 117 (80.7%) of 145 sera samples (69.7% against BVDV-1a, 1.4% against BVDV-1b, 8.3% against BVDV-1c, and 1.4% against BVDV-2a). The results suggest that neutralization tests are useful in estimating currently epidemic subgenotypes of BVDV in the field.  相似文献   

3.
Genotypes and subgenotypes of bovine viral diarrhea virus (BVDV) field isolates from Japan, Germany and the United States of America (USA) were identified, and the prevalent pattern of BVDV in individual countries was estimated genetically. Subgenotypes were determined based on phylogenetic analyses of nucleotide sequences of a part of the E2-coding gene of BVDV. Forty-five, 61 and 56 BVDV strains were isolated from naturally infected cattle in Japan, Germany and USA, respectively, between 1980 and 2003. The most prevalent BVDV in these three countries was BVDV-1b. The second most prevalent BVDV strains were 1a, 1d and BVDV-2 in Japan, Germany and USA, respectively. The most prevalent subgenotype 1b in each country constructed individual small clusters in the subgenotype 1b branch in the phylogenetic tree. Although cattle and/or cattle products were moving among the three countries as part of international trade, the distribution of BVDV in the field in each country showed long-standing individual patterns.  相似文献   

4.
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5.
Vilcek S  Durkovic B  Kolesarova M  Paton DJ 《Preventive veterinary medicine》2005,72(1-2):31-5; discussion 215-9
Genetic typing of bovine viral diarrhoea virus (BVDV) is important for the precise classification of viruses as well as for the development of molecular epidemiology. BVDV isolates were usually typed based on comparison of genomic sequences from the 5'-untranslated region (5'-UTR), N(pro) and E2 region. Recently we have identified 11 genetic groups (subgenotypes) of BVDV-1. Our further experiments confirmed a new subgenotype, BVDV-1k, isolated from cattle in Switzerland. BVDV isolates from India were typed as BVDV-1b whereas BVDV-1c is a predominant subgenotype in Australia. The results of genetic typing of BVDV indicate that distribution of subgenotypes has no relationship to the geographic origin of viral isolates.  相似文献   

6.
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7.
Five BVDV species 2 (BVDV-2) isolates were detected from cattle in Turkey. Phylogenetic analysis was performed based on the 5′ untranslated regions (UTRs) and E2 coding gene regions, respectively. The isolates were closely related to BVDV-2a strains from North America and Canada used as references. This is the first report of the detection of BVDV-2 in naturally infected Turkish cattle. It is important to consider BVDV-2 for planning future BVDV control and vaccination programs in Turkey.  相似文献   

8.
为了解中国农业科学院特产研究所分子生物学重点实验室前期分离的牛病毒性腹泻病毒BVDV-JL毒株完整的基因序列信息,本试验对BVDV-JL F6代毒株进行了完整基因序列测定。利用反转录—聚合酶链式反应(RT-PCR)方法分段扩增了BVDV-JL分离毒株的7段cDNA片段,分别克隆于pMD18-T载体并进行测序。BVDV-JL株基因组序列全长为12276 bp,编码3901个氨基酸。基因组两端为非编码区5'UTR和3'UTR。基因比对及进化树分析结果表明BVDV-JL与BVDV CP7同源性最高,核苷酸同源性为93.2%,归类于BVDV-1b2基因亚型。BVDV-JL是第1个在中国报道的BVDV-1b2亚型毒株。了解BVDV-JL完整基因序列有利于中国BVDV流行病学调查。  相似文献   

9.
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10.
Several tests for Bovine viral diarrhea virus (BVDV) were applied to samples collected monthly from December 20, 2005, through November 27, 2006 (day 0 to day 342) from 12 persistently infected (PI) cattle with BVDV subtypes found in US cattle: BVDV-1a, BVDV-1b, and BVDV-2a. The samples included clotted blood for serum, nasal swabs, and fresh and formalin-fixed ear notches. The tests were as follows: titration of infectious virus in serum and nasal swabs; antigen-capture (AC) enzyme-linked immunosorbent assay (ELISA), or ACE, on serum, nasal swabs, and fresh ear notches; gel-based polymerase chain reaction (PCR) testing of serum, nasal swabs, and fresh ear notches; immunohistochemical (IHC) testing of formalin-fixed ear notches; and serologic testing for BVDV antibodies in serum. Of the 12 animals starting the study, 3 died with mucosal disease. The ACE and IHC tests on ear notches had positive results throughout the study, as did the ACE and PCR tests on serum. There was detectable virus in nasal swabs from all the cattle throughout the study except for a few samples that were toxic to cell cultures. The serum had a virus titer ≥ log10 1.60 in all samples from all the cattle except for 3 collections from 1 animal. Although there were several equivocal results, the PCR test most often had positive results. The BVDV antibodies were due to vaccination or exposure to heterologous strains and did not appear to interfere with any BVDV test. These findings illustrate that PI cattle may be identified by several tests, but differentiation of PI cattle from cattle with acute BVDV infection requires additional testing, especially of blood samples and nasal swabs positive on initial testing. Also, calves PI with BVDV are continual shedders of infectious virus, as shown by the infectivity of nasal swabs over the 11-mo study.  相似文献   

11.
To acquire epidemiological data on the bovine viral diarrhea virus (BVDV) and identify cattle persistently infected (PI) with this virus, 4,327 samples from Holstein dairy cows were screened over a four-year period in Beijing, China. Eighteen BVD viruses were isolated, 12 from PI cattle. Based on genetic analysis of their 5''-untranslated region (5''-UTR), the 18 isolates were assigned to subgenotype BVDV-1m, 1a, 1d, 1q, and 1b. To investigate the innate immune responses in the peripheral-blood mononuclear cells of PI cattle, the expression of Toll-like receptors (TLRs), RIG-I-like receptors, interferon-α (IFN-α), IFN-β, myxovirus (influenza virus) resistance 1 (MX1), and interferon stimulatory gene 15 (ISG15) was assessed by qPCR. When compared with healthy cattle, the expression of TLR-7, IFN-α, and IFN-β mRNA was downregulated, but the expression of MX1 and ISG-15 mRNA was upregulated in PI cattle. Immunoblotting analysis revealed that the expression of interferon regulatory factor 3 (IRF-3) and IRF-7 was lower in PI cattle than in healthy cattle. Thus, BVDV-1m and 1a are the predominant subgenotypes in the Beijing region, and the strains are highly divergent. Our findings also suggest that the TLR-7/IRF-7 signaling pathway plays a role in evasion of host restriction by BVDV.  相似文献   

12.
Bovine viral diarrhea virus (BVDV) is one of the most important pathogens to the cattle industry, causing a significant economic loss throughout the world. Despite the wide use of various control measures for BVDV, the disease remains prevalent. In this study, we achieved an efficient inhibition of NADL strain replication by plasmid-mediated shRNA targeting conserved regions of the viral genome. To further enhance the inhibiting efficiency, a dual shRNA expression plasmid, which could simultaneously express two different shRNA, was established and showed stronger inhibitory effects on virus replication. Moreover, the antiviral activity induced by the dual shRNA expression system was also evident on other BVDV-1 subgenotypes (BVDV-1a, BVDV-1b and BVDV-1c). Therefore, the dual shRNA system provides a more powerful strategy for inhibiting BVDV replication in a cross-resistance manner.  相似文献   

13.
The genetic characteristics, of 38 field isolates of bovine viral diarrhoea virus (BVDV) collected in 1999 from sick or healthy and persistently infected cattle of dairy farms situated in northern Italy, were investigated. A partial 5-untranslated region (5-UTR) sequence of each isolate was determined and a phylogenetic analysis was performed. All the isolates were classified as belonging to the BVDV-1 genotype and could be assigned to different BVDV-1 groups, namely BVDV-1b (n = 20), BVDV-1d (n = 6) and BVDV-1e (n = 10). Two remaining isolates could be classified as BVDV-1f and BVDV-1h, respectively. These results provided evidence for genetic heterogeneity of BVDV in Italy, and contribute to a better knowledge of the circulation of BVDV strains, and to their classification.  相似文献   

14.
The prevalence of bovine viral diarrhoea virus (BVDV) biotypes and subgenotypes was determined from 131 BVDV positive samples from a diagnostic laboratory. The majority of the isolates were from Oklahoma; however, other states including Kansas, Texas, and Arkansas were represented. These BVDV samples were from submissions of 76 live animals and 55 necropsy samples. There were 131 BVDV samples represented by 117 noncytopathic (NCP), 11 cytopathic (CP) and 3 cases with mixed NCP and CP biotypes. The NCP isolates were more common (P < 0.05) than the CP and NCP/CP combination. The BVDV samples were segregated into three subgenotypes by differential PCR and sequencing of a viral genomic region, 5'-untranslated region (5'-UTR). There were more BVDV1b subgenotypes 60/131 (45.8%) than BVDV1a, 37/131 (28.2%) or BVDV2a, 34/131 (26.0%) (P < 0.05). The organ system involvement included the major categories such as respiratory, digestive, mixed/multiple organs, abortions, and persistent infections (PI). All three BVDV subgenotypes were found in persistently infected (PI) cattle and respiratory diseases, both major requests for BVDV diagnosis. Only one of the 131 viruses was genetically similar to the strains present in U.S. vaccines.  相似文献   

15.
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16.
牛病毒性腹泻病毒（BVDV）是引起牛病毒性腹泻/黏膜病的重要病原,也是牛血清及其制品污染中的常见病原体。本研究从商品化胎牛血清中分离到一株致细胞病变（CP）型BVDV（GS2018株）,利用电镜观察、免疫荧光检测、分子鉴定、基因组测序及遗传进化分析对其进行鉴定。结果表明,GS2018株接种MDBK细胞后可见明显的细胞病变（CPE）,培养第4天病毒滴度达1×106.2·0.1 mL-1。病毒粒子呈圆形,直径为50~60 nm,间接免疫荧光检测为阳性;其5'UTR扩增片段与BVDV-2相应序列高度相似,病毒基因组包含12 235个核苷酸（nt）。5'UTR、Npro及E2基因系统进化分析发现,GS2018株与美国BVDV-2 USMARC-60764分离株核苷酸一致性达98%,证明其属于CP型BVDV-2a亚型。但GS2018株在NS2/3区无核酸片段插入,这与大多数CP型BVDV-2明显不同,说明BVDV致细胞病变可能涉及更复杂的机制。  相似文献   

17.
In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5′-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.  相似文献   

18.
Bovine viral diarrhea virus (BVDV) has various economic impacts associated with diarrhea, poor performance, an increase in the frequency of other infections and lethal outcomes. Both genotypes, namely BVDV-1 and BVDV-2, as well as different subgroups within these genotypes have been reported worldwide. Understanding the serological differences among the BVDV subgroups is important for disease epidemiology and prevention as well as vaccination programs. The aim of this study was to determine the serological relatedness among the subgroups in BVDV-1. For that purpose, sheep hyperimmune sera were collected against representative strains from 6 of the subgroups of BVDV-1 (BVDV-1a, -1b, -1d, -1f, -1h and -1l). The serum samples that gave the peak antibody titer to the homologous strains were used to perform cross neutralization assays. The highest homologous antibody titer (1:5160) was obtained against BVDV-1h. Regarding the cross neutralizing (heterologous) antibodies, the lowest titer (1:20) was produced by the BVDV-1f antiserum against the BVDV-1a and BVDV1-b viruses. The highest cross neutralizing titer (1:2580) achieved by the BVDV-1h antiserum was against the BVDV-1b strain. The cross neutralization results indicated particular serological differences between the recently described subgroup (BVDV-1l) and BVDV-1a/-1b, which are widely used in commercial vaccines. Considering the cross neutralization titers, it is concluded that selected BVDV-1l and BVDV-1h strains can be used for the development of diagnostic and control tools.  相似文献   

19.
The 475 strains of bovine viral diarrhea virus (BVDV) isolated from cattle in 12 prefectures of Japan in the last 7 years were phylogenetically classified as BVDV-1 or BVDV-2 on the basis of the nucleotide sequence of the 5'-untranslated region. BVDV-1 strains were further subtyped as 1a (101 strains), 1b (163), 1c (128), 1j (3), and So CP/75-like (1), and all of the 79 BVDV-2 strains belonged to subtype 2a. These 2a BVDVs contain two isolates that had high nucleotide identities with those of highly pathogenic BVDV-2 strains reported in North America (Pellerin et al., 1994). However, acute infection with severe mortality like North American outbreak was not observed and most of the present BVDV-2 strains were isolated from persistently infected (PI) cattle showing mild or no clinical sign. Moreover, it was revealed that 61.5% of the 39 PI cattle with cytopathogenic BVDVs did not show typical mucosal disease and 54.6% of the 405 PI animals only with non-cytopathogenic BVDVs were apparently healthy. The present results indicate that the prevention of the infection with an appropriate vaccine and active surveillance covering healthy cattle are required for the control of BVD.  相似文献   

20.
In the last decade, several studies were performed to characterise bovine viral diarrhoea virus (BVDV) isolates and define genetic groups by genotyping. Much data is now available from GenBank, predominantly sequences from the 5' untranslated region (5'-UTR). In order to find out whether genetic grouping of isolates from different countries could be harmonised, 22 new isolates from five countries were analysed in combination with published sequences. Eighteen of these isolates were typed as BVDV genotype 1 (BVDV-1), and one isolate from Argentina and three isolates from Brazil were typed as BVDV-2. BVDV-1 isolates were clustered into five previously defined genetic groups: BVDV-1a, b, d, e and f. Two isolates from Finland and one from Egypt formed a group which was tentatively labelled as BVDV-1j, since statistical support was low. By using a fragment of the Npro gene for typing, we found that these isolates fall into the same group as a deer strain, and are statistically significant. Some Swiss BVDV strains taken from GenBank were found in a new genetic group which was designated as BVDV-1k. The BVDV-2 isolates included in this study seemed to fall into two genetic groups.  相似文献   

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