Bovine viral diarrhea virus subgenotype 1b in water buffalos (Bubalus bubalis) from Brazil

Tropical Animal Health and Production - Serological studies have characterized the presence of the bovine viral diarrhea virus (BVDV) infection in water buffalo herds worldwide. However, the...     

Associations between Campylobacter fetus, Haemophilus somnus, Leptospira hardjo and bovine viral diarrhea virus antibody titers in dairy cattle from a California herd

In a cross-sectional study, the associations of age, serological status against Campylobacter fetus (CF), Haemophilus somnus (HS) and Leptospira hardjo (LH) with the seroprevalence of bovine viral diarrhea virus (BVDV) in dairy cattle were evaluated. Six hundred and thirty cattle from a herd in Tulare county of California were included in the study. Blood samples from the cattle were collected in December 1986. Enzyme-linked immunosorbant assay (ELISA) was used to determine the positive or negative status of cows against CF, HS, LH and BVDV antigens. Loglinear analysis was used to describe the relationships of four categorical variables with the seroprevalence of BVDV. The final loglinear model was interpreted as a logit model and obtained by conditioning on explanatory variables in the model found to relate significantly with BVDV seropositivity. The hierarchical logit model included two two-way interactions (BVDV × HS and BVDV × LH) and a three-way interaction (BVDV × CF × age). HS-seronegative cattle had 4.7 times greater odds of being BVDV-seropositive compared with HS-seropositive cattle. In contrast, LH-seropositive cattle had 2.7 times increased odds of BVDV seropositivity compared with LH-seronegative cattle. The presence of the three-way interaction term in the model involving age, CF and BVDV seroprevalence implies that among heifers, CF-seronegative and CF-seropositive animals had about the same odds of BVDV seropositivity (e.g. adjusted odds ratios = 20.5 vs. 24.5), whereas, among cows, CF-seronegative animals had at least twice the odds of being BVDV-seropositive than those of CF-seropositive animals (e.g. adjusted odds ratios = 23.0 vs. 11.0).     

牛病毒性腹泻病毒基因组结构与蛋白功能研究进展

牛病毒性腹泻病毒为黄病毒科(Flaviviridae)瘟病毒属(Pestivirus)的代表种,这个属的成员中还包括羊边界病毒(BDV)和猪瘟病毒(CSFV)。病毒基因组为单股正链RNA。论文就牛病毒性腹泻病毒已定位的4种结构蛋白、8种非结构蛋白以及3′和5′非翻译区的基因结构特征及其编码蛋白的合成与功能研究进行了综述,为牛病毒性腹泻的防控和疫苗研制提供参考。     

牛病毒性腹泻病毒E2蛋白单克隆抗体的制备及鉴定

为制备牛病毒性腹泻病毒(BVDV)的特异性单克隆抗体(MAb),用含有BVDV E2基因的真核表达质粒pcDNA-E2免疫4周龄～6周龄BALB/c鼠,取其脾细胞与骨髓瘤细胞SP2/0进行融合,以BVDV作为抗原建立间接ELISA筛选及4次连续克隆获得3株能稳定分泌抗E2MAb的杂交瘤细胞系,分别命名为2E2、3D12、4D6。MAb亚类鉴定表明,2E2和4D6为IgM类,3D12为IgG2a亚类,轻链均为κ链。经western blot和间接免疫荧光检测证明3株MAb针对E2的构象表位,并且3D12株MAb能与BVDV及猪瘟病毒(CSFV)结合,2E2和4D6MAb只能与BVDV结合。     

Investigation of bovine viral diarrhea virus infections in a range beef cattle herd

Bovine viral diarrhea virus (BVDV) infections resulting in clinical disease developed in calves, despite vaccination of dams and high maternal BVDV antibody titers in calves. Eight persistently infected (PI) calves born to immunocompetent dams were identified in the herd. Neutralizing BVDV antibody titers of PI calves had decreased greatly by the time the calves were 1 to 2 months old. Antibody titers of PI calves decreased more rapidly than antibody titers of calves that were not PI. Reduced antibody titers in PI calves allowed detection of BVDV in serum specimens of all PI calves by the time they were 8 weeks old. Persistent infection in suspect calves was detectable serologically and was confirmed by virologic examination of serum specimens 4 months after weaning, when the calves were 9 months old. Growth rates were reduced in viremic calves.     

牛病毒性腹泻病毒CC13B株全基因组序列及分析

从长春地区某牛场发生疑似为牛病毒性腹泻-黏膜病的病牛粪样中分离到1株病毒,经序列测定为牛病毒性腹泻病毒命名为BVDV CC13B株。核苷酸序列的测定结果显示,CC13B毒株的完全基因组序列由12 265个核苷酸组成,其中5′端非编码区包含380个核苷酸,3′端非编码区包含188个核苷酸。病毒基因组含有1个大的读码框架,编码1个由3 898个氨基酸组成的前体多聚蛋白。序列对比结果显示,CC13B毒株的核苷酸和氨基酸序列与国外CP-5A毒株同源性最高,分别为为96.2%和97.3%;而与国内分离株JZ05-1的同源性最低,分别为69.8%和71.0%。系统进化树分析结果表明,CC13B毒株与国内分离的长春184、Xinjiang-3156和H等分离株归类为BVDV基因Ⅰ型的Ib基因亚型。结果表明,长春地区近年发生的牛病毒性腹泻-黏膜病依然主要由BVDV基因Ⅰ型毒株引起。     

The use of a mass-action model to validate the output from a stochastic simulation model of bovine viral diarrhoea virus spread in a closed dairy herd

The spread of bovine virus diarrhoea virus (BVDV) in a closed dairy herd maintained under typical management conditions is studied using two approaches. In the first instance a stochastic computer model is used to simulate the month-to-month changes in the infection status of each animal. These results are contrasted with the results of a mass-action model which uses three differential equations. A comparison of the two approaches indicates that the results are in broad agreement. The stochastic approach has the benefit of providing an estimate of the probability of the infection becoming extinct and the herd becoming BVDV-free for different herd sizes.     

Pathogenicity of an Indian isolate of bovine viral diarrhea virus 1b in experimentally infected calves

The aim of this study was to determine the pathogenicity of an Indian bovine viral diarrhea virus (BVDV) 1b isolate in 7-9-months-old male calves. Infected (four) and control (two) calves were bled at three days interval for hematological, virological and serological studies until day 27. All infected calves developed respiratory illness, biphasic pyrexia, mild diarrhea, leucopenia and mild thrombocytopenia. Viraemia was demonstrated between 3 and 15dpi and the infected calves seroconverted by 15dpi. Prominent kidney lesions were endothelial cell swelling, proliferation of mesangial cells and podocytes leading to glomerular space obliteration. Degeneration and desquamation of cells lining seminiferous tubules were observed in two infected calves. Consolidation of lungs with interstitial pneumonia, mild gastroenteritis and systemic spread were also evident. It was concluded that Indian BVDV isolate induced moderate clinical disease in calves and glomerulonephritis resulting from acute BVDV infection was observed for the first time.     

Identification and eradication of bovine viral diarrhea virus in a persistently infected dairy herd.

A milking herd consisting of 55 Holstein cows had experienced abortions in several cows, as well as congenital malformations in 1 newborn calf. Bovine viral diarrhea virus was isolated from blood mononuclear cell samples obtained from several cattle, documenting 1 acute infection and 8 persistently infected carriers identified by clinical appearance and laboratory testing. Initial suspicion of persistently infected status in some, but not all animals, was facilitated by poor growth rates in some calves. Virus isolation was performed on transtracheal wash fluid obtained from acutely and persistently infected cattle with respiratory tract infection. We describe the measures taken to identify and characterize the infecting virus strain, and the series of actions taken to identify and eliminate persistently infected carriers in a herd experiencing several related problems that were shown to be caused by bovine viral diarrhea virus.     

牛病毒性腹泻病毒感染对猪瘟免疫的影响

猪瘟病毒（CSFV）与同属的牛病毒性腹泻病病毒（BVDV）同源性较高,抗原性上有交叉。本次调查对368份猪瘟免疫猪血清样本进行BVDV抗原检测,其中7份呈阳性,阳性率1.90%。对7份BVDV阳性血清采用ELISA和IHA两种方法检测猪瘟（CSFV）抗体水平,抗体合格率偏低,两者的结果符合率为71%。研究表明：BVDV在一定程度上干扰了猪瘟疫苗的免疫效果,影响抗体水平。     

牛病毒性腹泻病毒石河子株的分离与基因型鉴定

牛病毒性腹泻病毒(Bovine viral diarrhoea virus,BVDV)不同的基因型在抗原性方面存在差异,使疫苗免疫难以收到预期效果。本试验对分离到的BVDV石河子株和其他石河子分离株进行基因型鉴定,通过对病毒的遗传分类研究,为该病的防治和开发新的基因工程疫苗提供一定依据。采用免疫学试验、电镜观察、理化特性测定以及PCR技术、同源性比较等方法分离、鉴定1株BVDV石河子分离株,命名为BVDV shz132株,并应用系统发生分析方法鉴定该株与其他石河子分离株Manasis、hihezi148和Letuyi株的基因型。将免疫学鉴定为阳性的样品进行病毒分离,电镜观察分离的BVDV shz132株病毒直径为40~60 nm,为有囊膜的球形颗粒。理化鉴定结果与参考株BVDV Oregon C24V一致。根据BVDV基因组5-′UTR基因设计引物在发病牛淋巴结、肠道分泌物制备的悬液及其分离的病毒细胞培养物中均扩增得到了大小为267 bp的片段。核苷酸同源性分析结果表明BVDV shz132株与BVDV Osloss株的同源性最高(97.5%),BVDV Manasi株等与BVDV NADL株的同源性最高(97.8%);系统发生分析表明上述所有石河子分离株均属于BVDV-Ⅰ型。     

用RT-PCR方法检测猪瘟细胞苗中污染牛病毒性腹泻病毒

参考GenBank中牛病毒性腹泻病毒(BVDV)和猪瘟兔化弱毒病毒(HCLV)序列,设计和建立了一种PCR检测方法,通过试验证明,所建方法能够对HCLV和BVDV进行鉴别诊断;用此方法对23个批次的猪瘟细胞苗进行检测,发现有5批疫苗污染BVDV,均为BVDV I型,污染率为21.74%。测定序列与BVDV Oregon C24V株(AF091605)的核苷酸相似性为83.2%~83.5%,与NADL株(M31182)的核苷酸相似性为86.4%~86.7%。     

Diagnostic investigation of bovine viral diarrhea infection in a Minnesota dairy herd

Bovine viral diarrhea (BVD) virus infection was diagnosed in neonatal calves with enteritis. Successful diagnostic procedures included direct immunofluorescence of frozen tissue sections, histopathology, and virus isolation. Virus isolation from buffy coats and serum was successful in detecting infected animals, whereas direct immunofluorescence of buffy coat samples was found to be less reliable. Virus was not isolated from any fecal samples. Booster vaccinations and the culling of animals shedding virus resulted in improved calf viability in this herd. It is suggested that procedures for the diagnosis of BVD virus infection should always be included in the diagnosis of neonatal calf enteritis.     

Prevalence of bovine viral diarrhea virus in dairy cattle herds in eastern China

Tropical Animal Health and Production - Bovine viral diarrhea virus (BVDV) is a worldwide spreading pestivirus affecting cattle and other ruminants; however, there have been few reports on...     

Effect of the bovine viral diarrhoea virus (BVDV) infection on dairy calf rearing

The aim of this study was to compare the cumulative incidence of mortality, clinical diarrhoea and respiratory disease in calves, during their first six months of age, in herds with different bovine viral diarrhoea virus (BVDV) infection status. Calves’ health indicators were tested by comparing proportions in 101 farms with dissimilar infection condition. The results indicate that there was a significant relationship between the BVDV status (actively infected herd or not) and the cumulative incidence of mortality and respiratory disorders.