猪巨细胞病毒感染专述

最近,全球首例接受猪心脏移植的男子去世。研究人员在其移植的猪心脏中检出了猪巨细胞病毒（porcine cytomegalovirus,PCMV）DNA,这引起了对该病毒的广泛关注。PCMV分布相当广泛;具有高度的宿主特异性,仅感染猪;能够引起感染仔猪死亡,成年猪通常呈现隐性感染;在临床生产中往往不易引起人们重视。PCMV感染尚无特效治疗药物,因此成为养猪生产中的一大疫病隐患。本文从病原学、流行病学、临床症状、病理变化、实验室诊断及防治措施等方面,对PCMV感染加以综述,以引起人们对该病毒感染防控的重视。     

猪细小病毒PCR检测与分离研究

根据猪细小病毒(PPV)结构蛋白VP2基因序列,设计合成1对引物,建立了检测PPV的PCR方法。检测14份临床组织,检出阳性11份,阳性检出率为79.5%。阳性样品扩增产物用EcoRⅠ酶切得到了预期的结果,对PCR产物进行测序,测序结果与已发表的PPV基因核苷酸序列比较,同源性达99%~100%,所编码的氨基酸同源性为93%~100%。从PCR检测阳性的一份病料组织中分离出1株PPV。试验证明,建立的PPVPCR检测方法特异性强、敏感性高,适用于临床样品的快速检测。     

猪巨细胞病毒病

猪巨细胞病毒(Porcine Cytomegalovirus,PC-MV)是由疱疹病毒科β疱疹病毒亚科巨细胞病毒属的一种[1].该病毒遍布全球[2],猪感染该病也是普遍存在,在北美、欧洲和日本,90％以上的猪群曾受到感染.对成年猪只通常只呈现隐性感染,而对3周龄以下仔猪常常诱发致命性的全身感染[3].     

猪巨细胞病毒病研究进展

猪巨细胞病毒病作为一种传染性疾病,全世界98%以上的猪受到过本病毒的感染,感染猪群98%以上的血清抗体均呈阳性。该病主要通过上呼吸道传播和排毒,对猪场造成较大危害。本文就猪巨细胞病毒病的病原学、流行病学、临床症状、病理变化、诊断方法等方面作一综述。     

PCR与病毒分离检测 PPV感染的相关性研究

以PPVVP2基因为模板设计、合成了1对引物，成功地从PPV兔体传代的组织及其细胞培养物中扩增出了312bp的特异性片段。敏感性试验表明，PCR扩增可以检测10^-4TCID50的病毒含量。利用该方法对12份PPV兔体传代的组织上清进行检测，查出了10份阳性；同时利用病毒分离、HA检测，查出了7份阳性。这些结果表明，本试验建立的PCR检测方法具有敏感性好、特异性强等特点，完全可以用于PPV感染的临床检测。     

鸡新城疫强毒株的分离及其人工感染试验

采用鸡胚接种法从安徽凤阳某患病鸡群中分离到一株病毒，经HA、HI试验及知清中和接种鸡胚试验，确定为新城疫病毒。参照国际上规定的新城疫病毒力判定的标准及其方法，测定该分离株的鸡胚是小致死量平均死亡时间（MDT）、1日龄鸡脑内接种致病指数（ICPI）和6周龄鸡静脉内接种致病指数（IVPI）分别为44h、1．74和2．39。表明该分离株具有与新城疫病毒发型相类似的毒力，属强毒力毒株。用该分离株对16日龄的鸡、鹅、鸭分别进行了人工试验感染，其发病率均为100％，而死亡率为分别为40％－80％、40％－60％和0。     

一例猪圆环病毒并发猪附红细胞体的诊治报告

2004年5月23日，我市松陵镇兽医站向我站报告该镇青树湾村某猪场猪群发病，已死亡3头。5月24日，我们会同苏州市兽医站专家前往会诊。该场共有肉猪740头，发病50头，病猪普遍出现体温升高，达41℃，精神沉郁，食欲减退，粪便干结，流泪，鼻有分泌物流出，阵发性咳嗽。初步诊断为猪流感。用卡那霉素、地塞咪松、氨基吡啉等药物增强抵抗力，防止继发感染。5天后病猪好转。     

Cloning and Sequencing Analysis of DPOL Gene of Porcine Cytomegalovirus

In order to know the DPOL gene characterization of porcine cytomegalovirus (PCMV) (PCMV-FJ01 strain),three pairs of specific primer were designed by Oligo 7.0 software based on comparison the characterization of DPOL gene retrieved from GenBank.The target DPOL gene fragments were amplified using PCR methods with the strain PCMV-FJ01 genomic DNA. The target PCR fragments were cloned and sequenced. The assembly sequences were bioinformatics analysis. The DPOL gene of PCMV-FJ01 strain was 3 021 bp in length, coding 1 006 amino acids. The results showed that the homology of the nucleotide sequence and amino acid sequence were above 98.7% and 99.1%, respectively. Phylogenetic analysis revealed that the PCMV was closer with genus Roseolovirus rather than genus Cytomegalovirus. The results suggested that PCMV should be new species under genus Roseolovirus base on the phylogenetic relationship.     

猪巨细胞病毒福建株DPOL基因的克隆及序列分析

为了明确猪巨细胞病毒（porcine cytomegalovirus,PCMV）福建株（PCMV-FJ01株）DPOL基因特征,本研究根据GenBank数据库中PCMV DPOL基因序列特征,利用引物设计软件Oligo 7.0设计针对DPOL基因的引物,以PCMV-FJ01株核酸DNA为模板,对其进行分段PCR扩增。将分段扩增的产物经胶回收试剂盒回收后进行克隆测序,对测序结果进行拼接后获得PCMV-FJ01株DPOL基因序列,并进行生物信息学分析。结果表明,PCMV-FJ01株DPOL基因全长为3 021 bp,编码1 006个氨基酸;其与GenBank中的PCMV分离株DPOL基因核苷酸和氨基酸同源性分别在98.7%和99.1%以上。遗传进化分析发现,相对于巨细胞病毒属其他种代表株,PCMV分离株DPOL基因在遗传进化上和玫瑰疱病毒属代表株更近。建议根据PCMV DPOL基因遗传进化特征,将其划归为玫瑰疱病毒属的一个病毒新种--猪玫瑰疹病毒（porcine roseolovirus）。     

猪Kobu病毒感染概况

猪Kobu病毒是小核糖核酸病毒科Kobu病毒属成员,是2008年从匈牙利健康猪群中分离到的新病毒,目前在一些亚洲和欧洲的国家均报道了本病毒感染的发生。论文重点对猪Kobu病毒在猪群中的感染状况进行了综述,该病毒在临床表现正常的猪群或表现腹泻病症的猪群均出现较高的阳性率,可能在猪的胃肠炎致病作用中充当了一定的角色。     

Vaccination Against Porcine Parvovirus Infection

Of 13 gilts 7 were vaccinated twice at an interval of 3 weeks with an inactivated vaccine against porcine parvovirus (PPV) infection, while the 6 nonvaccinated gilts served as controls. Starting after the 1st vaccination the gilts were bred and, after about 40 days of gestation, challenged intravenously with virulent PPV. The vaccinated gilts produced an antibody respons after the 1st and 2nd vaccination compatible with a primary and a secondary immune response, respectively. The nonvaccinated gilts remained low-titered or PPV antibody negative until after challenge. The gilts were killed after about 90 days of gestation, and their litters were examined. All of 53 fetuses from the vaccinated gilts were alive, and infection with PPV could not be demonstrated. Conversely, 50 of 65 fetuses from the non-vaccinated gilts were infected with PPV, and 43 were dead.In a field study comprising 2 herds, PPV seronegative or lowtitered gilts were vaccinated before mating. There were no obvious signs of reproductive disorders in the 2 herds during the vaccination trials, and the reproductive performance of vaccinated gilts did not differ significantly from that of non-vaccinated gilts.     

猪圆环病毒感染

猪圆环病毒感染是近几年发现的猪的一种病毒性传染病，它可以引起仔猪先天性震颤和断奶猪多系统衰弱综合征。大量的研究证实，猪圆环病毒感染已成为对全球养猪业构成重大危害的传染病。     

Fetal Infection with Porcine Parvovirus in Herds with Reproductive Failure

During a 20 months period in 1978 and 1979 aborted, macerated and mummified fetuses as well as stillborn piglets from herds with reproductive failure were examined for evidence of infection with porcine parvovirus (PPV). A total of 602 cases were examined and evidence of infection with PPV was found in 269 (45 %). In 52 % of these antibody to PPV was found. Infective PPV as well as antibody to PPV were found in 41 %, whereas infective PPV alone was found in 7 %. When abortions were excluded from the results a high prevalence of infection with PPV (73–90 %) was found among fetuses of all sizes with the exception of fetuses dead late in gestation or at term.     

猪细小病毒的分离与鉴定

本试验从福建省某猪场疑似猪细小病毒病死胎的淋巴结、肝脏中分离到1 株病毒。病料接种PK-15细胞36 h后出现了圆缩、集聚、脱落等细胞病变,猪细小病毒阳性血清能特异性地中和该分离病毒。根据已发表的细小病毒(PPV) VP2基因的序列设计并合成了一对引物,采用PCR方法可扩增531 bp DNA片段。测序结果表明,分离株VP2基因与NCBI公布的NADL-2株的同源性高达99.2％,证实分离的病毒株为猪细小病毒。为进一步开展该病毒致病机理、流行病学、诊断研究与疫苗免疫等奠定了基础。     

一株猪捷申病毒的分离与鉴定

北京地区某猪场猪群疑似感染猪捷申病毒(porcine teschovirus,PTV),为了分离与鉴定该病毒,从采集的脑组织样品中分离出病毒,并从病毒中提取总RNA,根据已报道的引物序列,经RT-PCR扩增得到部分编码主要结构蛋白的VP1基因和高度保守的5'-UTR区基因序列,将这些基因克隆到pEASY-Blunt载体中,经序列测定,与GenBank上的毒株序列进行比对。试验结果表明,分离的毒株与猪捷申病毒同源性为95%~100%。本试验成功分离获得一株猪捷申病毒北京地方流行毒株,命名为 10BJ02株。     

猪圆环病毒2型感染对猪繁殖与呼吸综合征灭活疫苗体液免疫的影响

本试验采用ELISA方法对单独接种猪繁殖与呼吸综合征病毒(PRRSV)变异株灭活苗组(HP组,n=3)和PCV2感染且出现病毒血症后接种PRRSV变异株灭活苗组(PCV2/HP组,n=3)不同时相血清中的PRRSV抗体进行检测;并对HP和PCV2/HP组血清中PCV2特异的抗体和核酸分别进行ELISA和荧光定量PCR检测。结果表明,在首免后70 d HP组血清平均抗体效价极显著高于PCV2/HP组(P<0.01);首免后56、63和77 d HP组平均抗体效价明显高于PCV2/HP组。其中在首免后56和63 d HP组抗体阳性率均达67%(2/3),PCV2/HP组在相应时相抗体阳性率为0;在首免后70和77 d HP组抗体阳性率均达100%(3/3),PCV2/HP组在相应时相抗体阳性率仅为0和33%(1/3)。结果提示PCV2感染可在一定程度上抑制PRRSV变异株(JXA1)特异性的抗体反应。     

仔猪圆环病毒病继发葡萄球菌感染的诊治

2020年4月,山东省威海市某猪场发生一起以哺乳仔猪精神不振、体温升高以及头部、颈部、背部、四肢出现多处皮肤化脓性坏死结痂为基本特征的疾病,发病率为32.43%,病死率为16.67%。为确诊病原,探究病因,采集病猪血液与患处脓液进行生化试验、药敏试验和胶体金试纸检测。结果显示:胶体金试纸检测为猪圆环病毒阳性,生化试验结果符合葡萄球菌特性,结合临床症状与剖检病变,确诊为猪圆环病毒病继发葡萄球菌感染。根据药敏试验结果,选用高敏感的头孢噻呋钠对病猪进行注射治疗,并在产房内外喷洒消毒液,同时全猪群紧急免疫接种猪圆环病毒Ⅱ型灭活疫苗,由此疫情得到有效控制。这提示,规模化猪场既要重视免疫抑制性疫病的控制,也要加强猪场环境卫生与猪群饲养管理。本研究可为猪圆环病毒病并继发细菌感染的诊断与治疗提供参考。     

Experimental Dual Infection of Specific Pathogen‐Free Pigs with Porcine Reproductive and Respiratory Syndrome Virus and Pseudorabies Virus

Twenty 6‐week‐old specific pathogen‐free pigs were divided into four groups. On day 0 of the experiment, PRRSV–PRV (n = 6) and PRRSV (n = 4) groups were intranasally inoculated with porcine reproductive and respiratory syndrome virus (PRRSV) (10^5.6 TCID₅₀). On day 7, the PRRSV–PRV and PRV (n = 6) groups were intranasally inoculated with pseudorabies virus (PRV) (10^3.6 TCID₅₀). Control pigs (n = 4) were kept as uninoculated negative controls. Half of the pigs in each group were euthanized and necropsied on day 14 or 21. Clinical signs such as depression and anorexia were observed in the PRRSV–PRV and PRV groups after inoculation with PRV. Although febrile response was observed after virus inoculations, the duration of that response was prolonged in the PRRSV–PRV group compared with the other groups. The lungs in the PRRSV–PRV group failed to collapse and were mottled or diffusely tan and red, whereas the lungs of the pigs in the other groups were grossly normal. Histopathologically, interstitial pneumonia was present in all PRRSV‐inoculated pigs, but the pneumonic lesions were more severe in the PRRSV–PRV group. Mean PRRSV titres of tonsil and lung in the PRRSV–PRV group were significantly (P < 0.05) higher than that in the PRRSV group on day 21. These results indicate that dual infection with PRRSV and PRV increased clinical signs and pneumonic lesions in pigs infected with both viruses, as compared to pigs infected with PRRSV or PRV only, at least in the present experimental conditions.