猪瘟猪O型口蹄疫高致病性猪蓝耳病疫苗联合免疫试验报告

为了评价猪瘟、口蹄疫、猪蓝耳病疫苗联合免疫效果,采用猪瘟脾淋苗、猪O型口蹄疫缅甸98灭活疫苗和猪繁殖与呼吸综合征活疫苗对33～50日龄健康仔猪同时分点注射进行联合免疫,用正向间接血凝试验和ELISA试验检测其免疫效果。结果表明,3种疫苗联合免疫具有较高安全性,猪瘟脾淋苗、猪O型口蹄疫缅甸98灭活疫苗(浓缩)和高致病性猪蓝耳病灭活苗同时分点注射,对猪瘟脾淋苗和猪O型口蹄疫缅甸98灭活疫苗免疫效果无明显的免疫抑制或干扰作用,但对高致病性猪蓝耳病灭活苗免疫效果有显著的抑制或干扰作用。猪瘟脾淋苗、猪O型口蹄疫缅甸98灭活疫苗可进行联合免疫,但高致病性猪蓝耳病灭活疫苗应单独免疫。     

口蹄疫O型重组病毒的构建及其生物学特性分析

传统灭活疫苗的免疫接种是预防和控制口蹄疫的重要手段,但口蹄疫病毒极易发生变异而常导致新突变株的产生,从而使现有疫苗不能有效防控当前流行的口蹄疫,经常需要筛选与当前流行毒株抗原匹配性好、免疫原性和复制特性优良的疫苗候选毒株。在比对分析Cathay和Pan-Asia谱系不同时间经典疫苗毒株和我国当前主要流行毒株(SEA-Mya98谱系)VP1结构蛋白的基础上,借助反向遗传操作技术,在已构建含当前流行毒株VP1基因全长感染性克隆的骨架上,引入2个氨基酸的替换(VP1 H28Q+S47Q),构建重组全长质粒,并通过转染表达T7RNA聚合酶的BSR/T7细胞成功拯救到活的重组病毒。重组病毒具有和亲本病毒相似的噬斑表型和一步生长曲线,却降低热稳定性,增强了对乳鼠的致病力。研究结果为进一步开发与当前流行毒株抗原匹配性好、免疫原性和复制特性优良的FMD疫苗候选毒株奠定了基础。     

融合表达牛疱疹病毒Ⅰ型VP22基因和O型口蹄疫病毒P12A3C基因的DNA疫苗的构建及其免疫应答

用小鼠模型评价融合表达牛疱疹病毒Ⅰ型VP22基因和O型口蹄疫病毒P12A3C基因的DNA疫苗和不同免疫策略的免疫应答.用PCR方法扩增牛疱疹病毒Ⅰ型VP22基因和O型口蹄疫病毒P12A3C基因,分别克隆到pMD18-T载体并测序验证正确后将其克隆到质粒pcDNA的相应位点获得质粒pcDNA-VP22-P12A3C.然后将BALB/c小鼠分成7组进行免疫.结果表明,DNA疫苗pcDNA-VP22-P12A3C诱导的细胞免疫水平超过了灭活疫苗,DNA疫苗与灭活疫苗联合免疫组体液免疫水平接近灭活疫苗组而细胞免疫水平远高于灭活疫苗组,为进一步研究VP22和P12A3C融合表达的基因工程疫苗奠定了基础.     

猪口蹄疫O型合成肽疫苗免疫效果试验

为了更好地了解猪口蹄疫O型合成肽疫苗与灭活疫苗免疫后抗体水平之间的差异．在梅小市选择2个规模化养猪场,每个猪场分2组,对试验猪分别免疫猪口蹄疫O型合成肽疫苗和猪口蹄疫O型灭活疫苗．对接种疫苗的试验猪进行免疫应激观察,结果显示：注射合成肽疫苗试验猪未出现不良免疫副反应．说明用合成肽疫苗临床使用的安全性较高;采用猪O型口蹄疫VP1抗体检测试剂盒和正向间接血凝试验分别对使用上述两种口蹄疫疫苗免疫21d后的猪血清进行检测,结果表明：免疫猪口蹄疫O型合成肽疫苗用猪O型口蹄疫VP1抗体检测试剂盒检测．抗体阳性合格率达到92．50％,免疫猪口蹄疫O型灭活疫苗用正向间接血凝试验检测,免疫合格率为35．83％,说明猪口蹄疫O型合成肽疫苗接种后的免疫效果明显优于传统灭活疫苗。     

三种试剂盒检测猪口蹄疫O型抗体的对比试验

使用三种猪口蹄疫O型抗体检测试剂盒分别检测接种猪口蹄疫O型合成肽疫苗和猪口蹄疫O型灭活疫苗的免疫抗体,以探讨三种抗体检测试剂盒的相关性。结果发现,猪口蹄疫病毒VP1结构蛋白抗体ELISA试剂盒和猪口蹄疫O型液相阻断ELISA试剂盒都可检测猪口蹄疫O型合成肽疫苗,两种试剂盒的相关性达90.8%,而间接血凝试剂盒不能用来检测猪口蹄疫O型合成肽疫苗;猪口蹄疫O型液相阻断ELISA试剂盒和间接血凝试剂盒可用来检测猪口蹄疫O型灭活疫苗,两种试剂盒的相关性达93.7%,而猪口蹄疫病毒VP1结构蛋白抗体ELISA试剂盒不能用来检测猪口蹄疫O型灭活疫苗。     

不同口蹄疫疫苗免疫效果及检测方法评估

为更好地了解猪口蹄疫O型合成肽疫苗与猪口蹄疫O型灭活疫苗的免疫效果与合理的检测方法,广西农垦永新畜牧集团有限公司良圻原种猪场在某肥育场进行了此次试验。试验猪分3组,分别注射不同厂家生产的猪口蹄疫O型合成肽疫苗和猪口蹄疫O型OS／99株灭活疫苗,并采用猪O型口蹄疫VP1抗体检测试剂盒和正向间接血凝试验（HI）分别对使用上述口蹄疫疫苗免疫效果进行检测。结果表明,猪注射口蹄疫O型合成肽疫苗后,用猪0型口蹄疫VP1抗体检测试剂盒检测,抗体阳性率达到100％;用正向间接血凝试验方法检测不到注射合成肽疫苗后产生的抗体效价。免疫猪口蹄疫O型OS／99株灭活疫苗后,用VP1抗体检测试剂盒检测,抗体阳性率只有30％;用HI方法进行检测,抗体阳性率为60％。     

口蹄疫基因工程疫苗研制成功

一项具有自主知识产权的猪口蹄疫O型基因工程苗在上海通过由教育部主持的成果鉴定。据该项目主持人郑兆鑫教授介绍，猪口蹄疫O型基因工程疫苗在生产过程中不需要像灭活疫苗那样培养大量高致病性强毒，不存在散毒的问题，在生产和使用中是安全的，这项研究技术创新表现在疫苗基因的构建上，找到了最佳病毒抗原表位基因结合串联结构；连接肽和表达载体设计新颖。科研人员还建立了常规方法不同的免疫蛋白变性和复性以及发酵的工艺路线，通过免疫实践证明，该疫苗具有很强的免疫保护作用。     

安徽省2015年规模场秋季重大动物疫病免疫抗体监测与评价

为评估安徽省2015年秋季政府采购重大动物疫病疫苗的临床免疫效果,在全省16个市、2个直管县,随机选取427个规模养殖场,采集畜禽血清9 918份,利用ELISA、HA/HI试验进行血清学抗体检测。结果显示：猪瘟活疫苗（细胞源）、口蹄疫O型合成肽苗、A型口蹄疫灭活疫苗、小反刍兽疫弱毒疫苗、高致病性猪蓝耳病活疫苗、禽流感灭活苗（H5）的免疫抗体合格率分别为88.0%、86.8%、94.3%、89.6%、87.8%、82.0%;而3种灭活疫苗的免疫效果较差,猪O型口蹄疫灭活苗、牛羊O－亚I型口蹄疫灭活苗、高致病性猪蓝耳病灭活苗的免疫抗体合格率分别为41.0%、41.3%、50.5%。建议今后要加强O型和亚I型口蹄疫灭活疫苗以及高致病性猪蓝耳病灭活疫苗的使有效果监测。     

集约化养猪场口蹄疫免疫程序探讨

本试验采用中国农业科学院兰州兽医研究所提供的液相阻断ELISA和上海优耐特生物医药有限公司提供的口蹄疫病毒结构蛋白VP1猪用酶标试剂,检测猪血清样品中口蹄疫疫苗中和抗体,探讨猪O型口蹄疫灭活疫苗免疫效果,为集约化养猪场建立合理的口蹄疫免疫程序提供科学依据。     

科技

正兰州兽医所创制全球首例口蹄疫病毒标记疫苗10月16日,由中国农业科学院兰州兽医研究所联合相关企业创制的口蹄疫病毒标记疫苗"猪口蹄疫O型病毒3A3B表位缺失灭活疫苗(O/r V-1株)"成功获批注册。该疫苗是国际上首例能够精准鉴别口蹄疫病毒感染与疫苗免疫动物的新型生物制品。     

O型口蹄疫病毒不同基因型联合RT-PCR检测方法的建立

在比较国内外口蹄疫病毒(FMDV)流行毒株序列的基础上，设计了检测FMDV的PCR引物及O型FMDV不同基因型即中国型(Cathay)与乏亚株(PanAsia)的二联PCR引物。在确定单项RT-PCR反应条件的基础上，建立、优化了二联RT-PCR反应体系和条件，并进行了相关病毒检测试验。结果表明，建立的检测O型FMDV不同基因型中国型与泛亚株的二联RT-PCR，有效、特异且敏感，为FMD的诊断、流行病学调查及疫苗应用奠定了基础。     

2019—2021年伊吾县牛羊口蹄疫免疫抗体监测与分析

为掌握伊吾县牛羊口蹄疫免疫抗体水平,采用液相阻断ELISA抗体检测(LPB-ELISA)方法,收集6个乡镇2019—2021年抽检春秋两季牛1258头、羊2496只,进行时间、地域分布描述。实验显示,口蹄疫A型总体合格率90.86%、90.91%,O型口蹄疫免疫抗体总体合格率94.12%、94.03%,免疫抗体效价大于70%。不同区域前山乡口蹄疫整体免疫水平最高,吐葫芦乡牛A型口蹄疫免疫抗体较低仅为74.67%。结果表明,全县牛羊口蹄疫免疫抗体检测效果整体良好,部分乡镇免疫较低。需做好基层牛羊口蹄疫免疫调研,查找原因,提出了今后的工作方向,加强对防疫员开展从疫苗保存、免疫部位选择、免疫剂量技术指导,特别是动物检疫站监管,为伊吾县畜牧业高质量健康发展提供依据。     

The application of time series analysis to determine the pattern of foot-and-mouth disease in cattle in Paraguay

The temporal distribution of foot-and-mouth disease (FMD) in cattle in Paraguay, from 1972 to 1979, was examined using time series analysis. This technique was used to remove data irregularities which may complicate data analysis. The results showed that one secondary peak and two major cycles occurred during that period. It was determined that the secondary peak was due to a sporadic outbreak of FMD caused by type C virus. The two major cycles were predominantly due to type O virus which was found to have a 3 to 4 year frequency. This temporal pattern may aid administrators by elucidating times when increased control activities should be implemented to counteract the periodic epidemics. Time series analysis may be used to evaluate the temporal pattern of other diseases in addition to FMD, and aid in their control programs.     

Increased humoral antibody response of foot-and-mouth disease virus vaccine in growing pigs pre-treated with poly-γ-glutamic acid

This study was conducted to determine if humoral antibody response of foot-and-mouth disease (FMD) vaccine improved in 8-week-old growing pigs born to well-vaccinated sows pre-treated with 60 mg of poly-γ-glutamic acid (γ-PGA) three days before vaccination. Antibody against FMD virus serotype O was measured 0, 2, 4 and 6 weeks post-vaccination, using a PrioCHECK FMDV type O ELISA kit. The results showed that positive antibody reactions against FMDV serotype O antigen among a component of the vaccine significantly increased in response to pre-injection with γ-PGA.     

An enzyme-linked immunosorbent assay (ELISA) for the primary diagnosis of foot-and-mouth disease. Characterization and comparison with complement fixation

A sandwich type ELISA for foot-and-mouth disease (FMD) virus types O, A and C was established, using a combination of rabbit anti-146 S and guinea pig hyperimmune antibodies. This method was found to be highly efficient for the detection of both 146 S particles and 12 S subunits. The ELISA was approximately 500 times more sensitive than complement fixation (CF) when examining epithelial samples of FMD vesicles. An early primary diagnosis of FMD was obtained by both CF and ELISA in 19 out of 21 confirmed cases. The remaining 2 cases were initially negative in CF but positive in ELISA.     

Experimental placental transfer of foot-and-mouth disease virus in mice.

An attenuated type O foot-and-mouth disease (FMD) virus which was virulent for infant, but not for pregnant, mice proved to be superior to a virulent type C FMD virus in the development of a model system for the study of placental transfer of FMD in mice. When mice were inoculated at day 8 or 12 of gestation with type O FMD virus, the virus was detectable in the maternal pancreas for 3 days and in the placenta for 6 days. Viral levels in the fetus and the amniotic fluid were inconsistent and were apparently due to a spillover from the placental infection. The elimination of the virus from the placenta coincided with the expected production of maternal 7S antibody. Mice inoculated from days 0 to 12 of gestation did not have a significant increase in dead young by day 18 (the day of necropsy). Similarly inoculated mice, when permitted to go to term, produced and raised normal-size litters. Inoculation on day 15 of gestation resulted in an increased number of deaths due to morbidity of the dams. It was concluded that the placenta serves as an active site of infection for FMD virus in pregnant mice, but the fetus is relatively resistant to infection.     

牛口蹄疫病防治

牛口蹄疫是国家一类重特大传染性疾病,会严重威胁地区牛养殖产业的安全,给养殖户带来巨大经济损失,降低牛养殖产业的生产效益。再加上牛口蹄疫是一种人畜共患病,疾病传播流行中,如果没有做好个体防护很易造成病毒,向人扩散蔓延,威胁周边居民的生命财产安全。在充分掌握牛口蹄疫病发生现状的基础上,需要进行认真细致的分析,构建针对性的防控措施,降低疾病发生流行造成的危害。在充分掌握新宾县牛口蹄疫发生现状的基础上,对牛口蹄疫疾病的诊断和提出防治措施。     

Molecular epidemiological studies on foot-and-mouth disease type O Taiwan viruses from the 1997 epidemic

Sequence diversity was assessed of the complete VP1 gene directly amplified from 49 clinical specimens during an explosive foot-and-mouth disease (FMD) outbreak in Taiwan. Type O Taiwan FMD viruses are genetically highly homogenous, as seen by the minute divergence of 0.2-0.9% revealed in 20 variants. The O/HCP-0314/TW/97 and O/TCP-022/TW/97 viral variants dominated FMD outbreaks and were prevalent in most affected pig-raising areas. Comparison of deduced amino acid sequences around the main neutralizable antigenic sites on the VP1 polypeptide showed no significant antigenic variation. However, the O/CHP-158/TW/97 variant had an alternative critical residue at position 43 in antigenic site 3, which may be due to selective pressure in the field. Two vaccine production strains (O1/Manisa/Turkey/69 and O1/Campos/Brazil/71) probably provide partial heterologous protection of swine against O Taiwan viruses. The type O Taiwan variants clustered in sublineage A1 of four main lineages in the phylogenetic tree. The O/Hong Kong/9/94 and O/1685/Moscow/Russia/95 viruses in sublineage A2 are closely related to the O Taiwan variants. The causative agent for the 1997 epidemic presumably originated from a single common source of type O FMD viruses prevalent in neighboring areas.     

O型和Asia1型口蹄疫病毒感染RT-PCR鉴别诊断方法的建立

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。