畜禽痘病的病原与防治

<正>痘病是由痘病毒引起各种家畜、家禽和人类共患的急性、热性、接触性传染病。哺乳动物痘病的特征是在动物皮肤上出现痘疹,禽痘则在表现在禽皮肤上产生增生性和肿瘤样病变。1病原痘病的病原是痘病毒。痘病毒属于痘病毒科脊椎动物痘病毒亚科,与痘病有关的有六个属,正痘病毒属、山羊痘病毒属。禽痘病毒属、兔痘病毒属、猪痘病毒属和副痘病毒属,痘病毒为双股脱氧核糖核酸     

猪痘的诊断及防治

猪痘是由痘病毒引起的一种急性、热性传染病。以皮肤出现红斑、丘疹、脓疱、结痂等病变为特征。痘病毒可细分为猪痘病毒和痘苗病毒，猪痘病毒很少接触感染，多数经蚊虫、蝇虫等传染媒介。根据病猪体表以痘疮、丘疹、水疙、脓疱结痂、痊愈等特殊病理经过，结合流行病学调查，基本可初步诊断猪痘病毒。同时，此病易于水疱病、口蹄疫等相混淆，鉴别不清，应注意鉴别诊断。文章阐述此病发病基本情况的基础上，自预防和治疗两个角度就综合防控此病做汇总阐述，要点性知识以供参考和借鉴。     

兔痘的临床症状与剖检特征

兔痘是由兔痘病毒引起的家兔的一种热性、急性、高度接触性的传染病。该病以皮肤出现红斑、丘疹，眼炎，以及内脏器官发生结节性坏死为典型临床特征。兔痘病毒属正痘病毒科痘病毒属。该病毒可在多种动物培养细胞如H细胞、猪肾细胞、     

猪痘的防治措施

正猪痘是一种急性热性传染病。临床特征为皮肤和粘膜上发生痘疹。其病原体有两种:一种是猪痘病毒,仅能使猪发病;另一种是痘苗病毒,能使牛、猪等多种动物感染。1流行病学本病是由猪痘病毒引起的急性热性传染病,在皮肤及某些黏膜上出现痘疹,只感染猪,常呈地方流行。本病常发生于仔猪和小猪,成年猪的抵抗力较强,猪痘主要通过损伤皮肤传染,在猪虱和其他吸血昆虫甚多、卫     

猪痘病的防治

猪痘是由猪痘病毒引起的一种急性、烈性传染病,以在皮肤及某些部位的粘膜上出现痘疹为特征。     

猪痘综合防控措施

猪痘感染致病病毒,有猪痘病毒、痘苗病毒。猪痘病毒很少接触感染,多数经蚊虫、蝇虫等传染媒介。文章分析猪痘感染典型症状,提出根据病猪体表以痘疮、丘疹、水疙、脓疱结痂、痊愈等特殊病理经过,结合流行病学调查,基本可初步诊断猪痘病毒。在此基础上,提出了改善猪场养殖环境;注意灭虫、灭蚊、灭蝇;加强通风管理;出现疑似病例,及早隔离诊治;等预控措施。在治疗方面,建议采用局部治疗;清洗、消毒;预控并发症;尝试用中药制剂等综合性的疗法,疗效会更好一些     

猪痘的诊断与中药防治

<正>猪痘是由痘病毒引起猪的一种急性、热性、接触性传染病,常被称为天花。1病原介绍病原为两种形态近似的病毒,一是猪痘病毒,属痘病毒科的猪痘病毒属;另一个是痘苗病毒,属正痘病毒属。前者是发生猪痘的主要病原。病毒粒子为砖形或椭圆形,基因组为双股DNA,有囊膜大型病毒。痘病毒对理化学因素抵抗力较弱。上皮组织中的病毒,对冷和干燥有抵抗力,在干燥条件下可保存1年以上,冻干的病毒可保存几年,在干燥痘痂皮中     

猪痘的诊断和中西医疗法

正猪痘是由猪痘病毒或痘苗病毒引起的一种急性、热性、接触性传染病,以皮肤发红斑、丘疹和结痂为主要特征。本病一年四季均可发生,各种年龄的猪均易感,1月龄左右的仔猪多发,大猪很少发病,一般能自然痊愈。寒冷季节、饲养环境差多发,发病率高,但死亡率低。如有并发支气管肺炎、肠炎或其他传染病时,死亡率相应增高。1病原分析猪痘病毒只能在猪源组织细胞内增殖,并在细胞胞浆内形成空泡和包涵体。痘苗病毒能使猪和其他多种动物感染,能     

表达猪圆环病毒2型CAP蛋白和猪IL-18的重组禽痘病毒的构建

为了构建共表达猪圆环病毒2型(PCV2)CAP蛋白和猪IL-18的重组禽痘病毒,本研究将CAP基因和猪IL-18基因分别置于pSY538的痘病毒启动子LP2EP2下,然后插入到含有痘苗病毒启动子P11启动的LacZ基因的禽痘病毒转移载体pSY681/lacZ中,获得重组转移质粒pSY681/CAP/IL18。将重组质粒pSY681/CAP/IL18转染入鸡胚成纤维细胞内,使CAP基因、猪IL-18基因和LacZ基因同源重组到禽痘病毒S-FPV-017中,产生重组禽痘病毒,经多次蓝斑克隆筛选纯化后,最终得到共表达CAP蛋白和猪IL-18的重组禽痘病毒(rFPV-CAP/IL18)。以rFPVCAP/IL18感染CEF,通过RT-PCR检测,CEF细胞中含CAP基因和猪IL-18基因的mRNA,间接免疫荧光试验证实感染rFPV-CAP/IL18的CEF能表达CAP蛋白。重组禽痘病毒能表达具有生物学活性的CAP和猪IL-18,为进一步的免疫效力研究奠定了基础。     

保育猪发生猪痘的诊断及病毒分离

江西某猪场的部分保育猪皮肤出现数量不等的痘斑,为确定其病原,根据猪痘病毒(AF410153.1)设计1对引物,以该场发病猪的皮肤痘痂提取DNA,采用PCR的方法扩增出与预期大小相符的目的条带,测序结果表明该扩增片段为猪痘病毒核酸序列,与猪痘病毒参考毒株(AF410153.1)的同源性为98%。利用PK15细胞盲传从病猪皮肤痘痂中分离到一株猪痘病毒,该分离株在PK15细胞上不产生细胞病变(CPE)。采用间接ELISA方法对该场的24份猪血样进行猪痘病毒抗体检测,结果猪痘抗体阳性血清数12份(阳性率50%)。     

猪痘病毒江西株(SWPV-JX01株)的分离鉴定

本试验利用PK15细胞从江西省某猪场疑似猪痘的保育猪皮肤痘痂中分离到1株病毒,该分离毒株在PK15单层细胞上能连续盲传培养,不产生明显的细胞病变,通过PCR扩增猪痘病毒P35基因,扩增序列与猪痘病毒参考株(AF410153.1)P35基因的核苷酸同源性为97.9%,表明该分离病毒为猪痘病毒,并命名为SWPV-JX01。将SWPV-JX01株F5代细胞培养液经肌肉和皮下注射感染兔和小鼠,人工感染80 h后,通过PCR检测不同组织的猪痘病毒P35基因,从兔的肾脏、脾脏、皮肤、心肌、淋巴结均能扩增到P35基因,且扩增序列与SWPV-JX01株同源性为100%。试验结果表明,SWPV-JX01株能在兔体内增殖,但不能在昆明鼠体内增殖。     

表达猪圆环病毒2型衣壳蛋白的重组猪痘病毒的构建及鉴定

为探索猪痘病毒（swinepox virus,SWPV）作为猪圆环病毒2型（porcine circovirus type 2,PCV2）疫苗载体的可行性,本试验以痘苗病毒启动子P11启动绿色荧光蛋白筛选标记,猪痘病毒TK基因为外源基因的插入位点,P28、P7.5启动子启动PCV2 ORF2基因,以猪痘病毒JX20G株为亲本病毒,采用同源重组技术分别构建了两株表达PCV2衣壳蛋白的重组猪痘病毒rSWPV11-28C和rSWPV11-7.5C。结果显示,重组猪痘病毒rSWPV11-28C和rSWPV11-7.5C均成功表达了PCV2衣壳蛋白,表达的蛋白能与PCV2单克隆抗体6E12发生特异性反应;痘苗病毒启动子P28的启动效果明显优于P7.5,P28适合用于启动目的基因;利用重组猪痘病毒制备的PCV2灭活疫苗免疫小鼠后,rSWPV11-28C疫苗组的PCV2抗体水平与某PCV2商品疫苗相当,该重组病毒的成功构建为PCV2相关疾病及其他疫病在猪群中的防控提供了新的方向。     

猪痘病毒TK、ORF121、ORF143基因缺失毒株的构建及其生物学特性的测定

为筛选猪痘病毒（SWPV）复制非必需区并测定其缺失株的生物学特性,本研究根据同源重组原理分别针对SWPV的TK（ORF063）、ORF121和ORF143基因设计引物。应用重叠延伸PCR技术拼接同源重组左右臂及EGFP筛选标记表达盒,将拼接片段分别转染到感染SWPV的PK15细胞。利用荧光显微镜观察标记含EGFP的单个蚀斑,筛选获取重组毒株。应用PCR及Western blotting对重组毒株进行鉴定。分别测定各毒株感染PK15细胞的蚀斑大小和皮下接种保育猪致病性。PCR结果表明,目的基因成功整合到相应位点,成功获得重组毒株rSWPV-TK、rSWPV-121和rSWPV-143;Western blotting结果显示,连续传代的重组毒株在PK15细胞上稳定表达外源蛋白。重组毒株在PK15细胞上形成的痘斑均小于亲本毒株,其中ORF121缺失株差异极显著（P<0.01）。各毒株均可导致保育猪痘斑形成,其中ORF121缺失株引起病变时间短,产生痘斑小,毒力较亲本下降。综上所述,本研究筛选到2个SWPV基因组中可供外源蛋白插入的复制非必需区ORF121和ORF143,为构建SWPV基因工程载体奠定了基础。     

Isolation and genetic characterization of swinepox virus from pigs in India

Swinepox virus (SWPV), a member of the genus Suipoxvirus causes generalized pock-like lesions on the body of domestic and wild pigs. Although outbreak has been reported in India since 1987, virus isolation and genetic characterization remained elusive. In September 2013, an outbreak of acute skin infection occurred in piglets in a commercial piggery unit at Rohtak district in Haryana, India. The presence of SWPV in scab samples collected from piglets succumbed to infection was confirmed by virus isolation, PCR amplification of SWPV-specific gene segments and nucleotide sequencing. Phylogenetic analysis of host-range genes of the SWPV revealed that the Indian isolate is genetically closely related to reference isolate SWPV/pig/U.S.A/1999/Nebraska. To the best of our knowledge this is the first report on isolation and genetic characterization of SWPV from pigs in India.     

Four sporadic cases of congenital swinepox

Four sporadic cases of congenital swinepox are described. The pigs were born with pox lesions over their entire bodies. Microscopic examination revealed ballooning degeneration of keratinocytes, cytoplasmic inclusions and intranuclear vacuolisation. Electron microscopy detected poxvirus particles in all four pigs. The virus was isolated from one pig and identified by HindIII restriction endonuclease digestion as swinepox virus.     

The interferon sensitivity of selected porcine viruses.

The objective of this study was to compare the sensitivity of 11 porcine viruses to the antiviral effects of porcine interferon-alpha in serum from piglets which had been infected 19 h previously with transmissible gastroenteritis virus, and of porcine interferon-beta prepared in PK-15 cells by induction with polyinosinic:polycytidylic acid, in yield reduction assays in pig kidney cells which were treated with interferon before virus challenge, and both before and after virus challenge. The most sensitive virus to both types of interferon was vesicular stomatitis. A porcine isolate of bovine herpesvirus type 1, hemagglutinating encephalomyelitis virus and porcine enterovirus types 1 and 2 were also highly sensitive to interferon-alpha. There was little reduction in the yield of porcine parvovirus or porcine rotavirus, while swinepox, swine influenza and transmissible gastroenteritis viruses were intermediate in their sensitivity to interferon-alpha. In addition to vesicular stomatitis virus, porcine adenovirus type 3, swine influenza, hemagglutinating encephalomyelitis and porcine rotavirus were highly sensitive to interferon-beta, while swinepox, bovine herpesvirus type 1, porcine parvovirus, transmissible gastroenteritis and porcine enteroviruses were less sensitive than the above viruses to interferon-beta, although all showed significant reductions in virus yield.     

Epizootic of concurrent cutaneous streptococcal abscesses and swinepox in a herd of swine.

Concurrent cutaneous abscesses and swinepox were observed in a herd of swine. An ungroupable hemolytic streptococcus was isolated from the abscesses. Tests indicated that streptococci isolated from different swine were similar if not identical. Swinepox lesions were observed on swine only after weaning. Lice (Haematopinus suis) were numerous on the suckling and weaned swine and appeared to be resistant to lindane. Abscesses, swinepox, and lice were eliminated after the swine were treated with an organic phosphate insecticide and antibacterial agents were added to the rations.     

Potential viral vectors for the stimulation of mucosal antibody responses against enteric viral antigens in pigs

Four viruses were compared for their ability to induce an intestinal antibody response in piglets. Antibodies were not detected in response to oral vaccination with either fowlpox virus or a baculovirus (BV). Simultaneous oral dosing and parenteral inoculation with high concentrations of BV in an oil emulsion adjuvant induced high levels of circulating virus neutralising (VN) antibodies, and also low levels of intestinal antibodies when booster doses of virus were given. In response to oral vaccination with swinepox virus (SPV), low levels of circulating and intestinal VN antibodies, and higher titres of antibodies reactive in an enzyme immunoassay, including intestinal antibodies of the IgA class, were detected. Oral vaccination with porcine adenovirus type 3 (PAV-3) stimulated both circulating and intestinal VN antibodies, and IgA antibodies were demonstrated in the intestinal contents. It was concluded that SPV and PAV-3 might be suitable vectors for the expression of genes encoding the protective antigens of porcine enteric viruses.     

Feline B7.1 and B7.2 proteins produced from swinepox virus vectors are natively processed and biologically active: potential for use as nonchemical adjuvants

Costimulatory ligands, B7.1 and B7.2, have been incorporated into viral and DNA vectors as potential nonchemical adjuvants to enhance CTL and humoral immune responses against viral pathogens. In addition, soluble B7 proteins, minus their transmembrane and cytoplasmic domains, have been shown to block the down regulation of T-cell activation through blockade of B7/CTLA-4 interactions in mouse tumor models. Recently, we developed swinepox virus (SPV) vectors for delivery of feline leukemia antigens for vaccine use in cats [Winslow, B.J., Cochran, M.D., Holzenburg, A., Sun, J., Junker, D.E., Collisson, E.W., 2003. Replication and expression of a swinepox virus vector delivering feline leukemia virus Gag and Env to cell lines of swine and feline origin. Virus Res. 98, 1-15]. To explore the use of feline B7.1 and B7.2 ligands as nonchemical adjuvants, SPV vectors containing full-length feline B7.1 and B7.2 ligands were constructed and analyzed. Full-length feline B7.1 and B7.2 produced from SPV vectors were natively processed and costimulated Jurkat cells to produce IL-2, in vitro. In addition, we explored the feasibility of utilizing SPV as a novel expression vector to produce soluble forms of feline B7.1 (sB7.1) and B7.2 (sB7.2) in tissue culture. The transmembrane and cytoplasmic regions of the B7.1 and B7.2 genes were replaced with a poly-histidine tag and purified via a two-step chromatography procedure. Receptor binding and costimulation activity was measured. Although feline sB7.1-his and sB7.2-his proteins bound to the human homolog receptors, CTLA-4 and CD28, both soluble ligands possessed greater affinity for CTLA-4, compared to CD28. However, both retained the ability to partially block CD28-mediated costimulation in vitro. Results from these studies establish the use of SPV as a mammalian expression vector and suggest that full-length-vectored and purified soluble feline B7 ligands may be valuable, nonchemical immune-modulators.     

Swinepox--skin disease with sporadic occurrence

Swinepox virus infection results in an acute, mild or subclinical course and is characterised by typical poxvirus skin lesions in affected pigs. Additionally, sporadic vertical swinepox virus transmission leads to congenital generalised infection and subsequent abortion or stillbirth. The present report describes the occurrence of epidermal efflorescences in two piglets after intrauterine natural suipoxvirus infection. No clinical abnormalities of the gilt and littermates as well as in other pigs from this herd were present. One of the affected piglets was stillborn and submitted for necropsy, the other animal was alive at birth, but died 3 days later. Histologically, a proliferative to ulcerative dermatitis with epithelial ballooning degeneration and characteristic intracytoplasmatic inclusion bodies was observed. The pathomorphological and histopathological suspected diagnosis of a poxvirus infection was confirmed by electron microscopy. Furthermore, the agent was identified as suipoxvirus by polymerase chain reaction. As demonstrated here, obvious skin lesions in suipoxvirus infection leads to a suspected diagnosis in newborn piglets on macroscopic examination. However, further post mortem examinations, including electron microscopy as well as molecular techniques are essential for the identification of the aetiology and the exclusion of differential diagnoses. Because the disease only affected two pigs there was only a small economic loss. A valid diagnostic plays an important role in advising farmers and for herd health monitoring.