An Inactivated Vaccine from a Field Strain of Bovine Herpesvirus-1(BoHV-1) has High Antigenic Mass and Induces Strong Efficacy in a Rabbit Model

Bovine Herpesvirus-1 （BoHV-1） is a DNA virus belonging to the family Herpesviridae, subfamily Alfaherpesvirinae; it is a worldwide pathogen, causing serious economic losses in livestock. In Colombia there have been multiple isolates of BoHV-1 that have been subjected to molecular characterization, classifying most of the country isolates as BoHV-I.1. In the present study we developed and evaluated an ethyleneimine binary inactivated isolate from the native BoHV-1 strain （C6rdoba-2） in a rabbit model of vaccination and infection. The vaccine was evaluated in two phases, one of immunogenicity with vaccination and a booster after 21 days, and an evaluation phase of protection against challenge with a highly virulent reference strain. The results demonstrate optimum serum-conversion, with protective neutralizing antibody titers 28 days post vaccination and optimal protection against challenge with the reference strain with decreased clinical signs of infection, protection against the onset of fever and decrease of virus excretion post challenge. In conclusion, our results show the enormous potential that an immunogenic inactivated vaccine has produced from the native BoHV-I.1 strain, which produces a high antigen mass to the vaccine to induce optimal immunity and protection, and it is a strong candidate for evaluation and possible future use in different cattle populations.

A Review: Interactions of Equine Herpesvirus-1 with Immune System and Equine Lymphocyte

Equine herpesvirus-1 (EHV-1) remains one of the most common viral pathogens affecting horses worldwide presenting as a persistent infection which can establish latency in nerve ganglia (trigeminal ganglion), lymphoid tissues of the respiratory tract and peripheral blood lymphocytes. EHV-1 infection induces both humoral and cellular immune responses in horses. Virus neutralising antibody, particularly in the nasopharynx, is to kill free virus shed from infected epithelial cells. Hence this antibody has important functions in reducing virus shedding and spreading infection to cohorts. Cellular immune responses, particularly those carried out by cytotoxic T lymphocyte (CTL), have been shown to be effective in killing virus-infected cells in vitro. This review underlines the state of knowledge regarding immunity to EHV-1 and also its interaction with equine lymphocyte. Finally, the review also includes the importance of the viral immediate early (IE) protein in the pathogenesis of EHV-1. This information can be used as the basis for future research.

Cloning and Sequence Analysis of Glycoprotein D Gene of Bovine Herpesvirus-1 Strain Luojing

By means of PCR,the gene encoding gD of bovine herpesvirus-1 (BHV-1) strain Luojing was amplified,cloned and sequenced.The nucleotide sequence of this gD gene was (1 251 bp,)encoding 417 amino acids.Comparied with the published P8-2 strain,the homology of the necleotide sequence is 99.92%,and that of the deduced amino acid sequence is 100%.The results indicated that gD of BHV-1 was highly conservative.

新疆部分地区马疱疹病毒1型感染的血清学调查

旨在了解新疆地区马疱疹病毒1型感染的流行现状和特点,本研究于2019—2020年从新疆乌鲁木齐、昌吉州、伊犁州、巴州16处规模化马场收集1657份马血清样品,采用酶联免疫吸附试验(ELISA)进行抗体检测,对不同地区、品种、性别及年龄马匹的马疱疹病毒1型抗体阳性率进行统计分析。结果显示,乌鲁木齐、伊犁州、昌吉州、巴州马疱疹病毒1型抗体阳性率分别为39.34%、22.56%、90.52%、5.00%;纯血马、混血马、哈萨克马、伊犁马、焉耆马、普氏野马的EHV-1抗体阳性率分别为20.34%、32.93%、44.92%、19.35%、5.00%、90.52%;普氏野马与家马的EHV-1抗体阳性率分别为90.52%和29.32%;家马中新疆本土品种马与引进品种马的EHV-1抗体阳性率分别为31.70%和25.50%;母马与公马的EHV-1抗体阳性率分别为38.84%和22.00%;处于幼年、青年、成年、老年阶段的马匹EHV-1抗体阳性率分别为35.37%、33.00%、34.31%、23.81%。结果提示,新疆乌鲁木齐、伊犁州、昌吉州、巴州规模化养殖场普遍存在EHV-1感染,且不同地区、品种、性别及年龄的马EHV-1感染率差异显著(P<0.05)。本研究为新疆地区EHV-1感染的探讨和防控工作提供调查数据。

Ⅷ群神经致病型马疱疹病毒1型的分离及鉴定

为研究伊犁马是否存在Ⅷ群神经致病型马疱疹病毒1型(EHV-1)的感染,并分析其遗传进化特征,本研究采集新疆伊犁昭苏县某马场93份伊犁马流产胎儿肺组织样品,经PCR鉴定为EHV-1阳性后,将部分EHV-1阳性的肺组织研磨上清液接种MDBK细胞,盲传3代,待出现细胞病变时收集细胞及培养上清,通过PCR及透射电镜对EHV-1进行鉴定,并对其进行不同基因的遗传进化分析。结果显示,93份临床样品中有43份样品呈EHV-1阳性。将其中11份阳性样品接种MDBK细胞盲传3代后,有4份出现细胞病变,电镜观察可见疱疹病毒典型的形态特征,且均经PCR检测到EHV-1 g B基因,表明分离到4株EHV-1,分别命名为XJ-YLZS-21、XJYLZS-22、XJ-YLZS-29和XJ-YLZS-31。同源性分析结果显示,4株EHV-1分离株gB基因序列与EHV-1参考株Ab4相应基因序列的同源性为100%。ORF30基因序列分析结果显示,4株分离株第2 254位均为鸟嘌呤(G),编码天冬氨酸(D),表明4株EHV-1分离株为神经致病型EHV。ORF68基因及其编码氨基酸序列的遗传进化分析结果显示,4株EHV-1分离株的核苷酸及氨基酸序列同源性均为100%,并处于独立的进化分支,将其划分为Ⅷ群神经致病型EHV-1。本研究首次在国内鉴定并分离到Ⅷ群神经致病型EHV-1,丰富了EHV-1的流行病学数据库,为EHV-1感染所致马流产的防控奠定了流行病学基础。

Importance of Viral Disease in Dairy Cow Fertility

Many viral diseases are endemic in cattle populations worldwide. The ability of many viruses to cross the placenta and cause abortions and fetal malformations is well understood. There is also significant evidence that viral infections have additional actions in dairy cows, which are reflected in reduced conception rates. These effects are, however, highly dependent on the time at which an individual animal first contracts the disease and are less easy to quantify. This paper reviews the evidence relating to five viruses that can affect fertility, together with their potential mechanisms of action. Acute infection with non-cytopathic bovine viral diarrhea virus (BVDV) in mid-gestation increases abortion rates or causes the birth of persistently infected calves. BVDV infections closer to the time of breeding can have direct effects on the ovaries and uterine endometrium, which cause estrous cycle irregularities and early embryo mortality. Fertility may also be reduced by BVDV-induced immunosuppression, which increases the susceptibility to bacterial infections. Bovine herpesvirus (BHV)-1 is most common in pre-pubertal heifers, and can slow their growth, delay breeding, and increase the age at first calving. Previously infected animals subsequently show reduced fertility. Although this may be associated with lung damage, ovarian lesions have also been reported. Both BHV-1 and BHV-4 remain latent in the host following initial infection and may be reactivated later by stress, for example associated with calving and early lactation. While BHV-4 infection alone may not reduce fertility, it appears to act as a co-factor with established bacterial pathogens such as Escherichia coli and Trueperella pyogenes to promote the development of endometritis and delay uterine repair mechanisms after calving. Both Schmallenberg virus (SBV) and bluetongue virus (BTV) are transmitted by insect vectors and lead to increased abortion rates and congenital malformations.BTV-8 also impairs the development of hatched blastocysts;furthermore, infection around the time of breeding with either virus appears to reduce conception rates. Although the reductions in conception rates are often difficult to quantify, they are nevertheless sufficient to cause economic losses, which help to justify the benefits of vaccination and eradication schemes.

Infectious laryngotracheitis virus in chickens

Infectious laryngotracheitis(ILT) is an important respiratory disease of chickens and annually causes significant economic losses in the poultry industry worldwide. ILT virus(ILTV) belongs to alphaherpesvirinae and the Gallid herpesvirus 1 species. The transmission of ILTV is via respiratory and ocular routes. Clinical and post-mortem signs of ILT can be separated into two forms according to its virulence. The characteristic of the severe form is bloody mucus in the trachea with high mortality. The mild form causes nasal discharge, conjunctivitis, and reduced weight gain and egg production. Conventional polymerase chain reaction(PCR), nested PCR, real-time PCR, and loop-mediated isothermal amplification were developed to detect ILTV samples from natural or experimentally infected birds. The PCR combined with restriction fragment length polymorphism(RFLP) can separate ILTVs into several genetic groups. These groups can separate vaccine from wild type field viruses. Vaccination is a common method to prevent ILT. However, field isolates and vaccine viruses can establish latent infected carriers. According to PCR-RFLP results, virulent field ILTVs can be derived from modified-live vaccines. Therefore, modified-live vaccine reversion provides a source for ILT outbreaks on chicken farms. Two recently licensed commercial recombinant ILT vaccines are also in use. Other recombinant and gene-deficient vaccine candidates are in the developmental stages. They offer additional hope for the control of this disease. However, in ILT endemic regions, improved biosecurity and management practices are critical for improved ILT control.

马疱疹病毒1型TaqMan实时荧光定量PCR检测方法的建立

为快速准确地检测马疱疹病毒1型(equine herpesvirus 1,EHV-1),本研究根据EHV-1基因组序列进化分析筛选出特异性较高的ORF68基因的保守区域设计引物与探针,建立了TaqMan实时荧光定量PCR检测方法。结果显示该方法线性关系良好,相关系数为0.999;灵敏度高,最低检测量为10.2拷贝/μL,比常规PCR敏感1000倍;特异性强,检测EHV-2、EHV-4、EHV-5、马动脉炎病毒和马流感病毒均无交叉反应;重复性好,组内及组间样本检测的Ct值均小于等于2%;对2020年收集的60份伴有呼吸道症状的马匹鼻试子进行检测分析显示本方法的阳性检出率(26.67%)高于SYBR GreenⅠ荧光定量PCR(23.33%)和常规PCR(21.67%)。本研究建立了一种快速、灵敏、稳定、特异性强的TaqMan荧光定量PCR检测方法,可用于EHV-1的快速诊断和核酸定量检测,为EHV-1的防控工作提供了有力手段。