猪伪狂犬病病毒鄂A株的分离鉴定

从湖北省某些猪场大批死亡的新生仔猪的脑及内脏中分离到的多株病毒,并用其中一代表毒株进行了全面鉴定。该病毒株在仓鼠肾传代细胞上连传１５代均出现典型细胞病变,用适应ＢＨＫ－２１细胞的病毒接种鸡胚成纤维细胞,Ｈｅｌａ细胞,Ｖｅｒｏ细胞,犊牛睾丸原代细胞,猪肾传代细胞ＩＢＲＳ－２均出现典型细胞病变,在电镜下可见到典型的伪狂犬病毒病粒子,病毒对５－碘脱氧尿核苷,氯仿,胰蛋白酶,乙醚敏感,在ｐＨ５．０～９．０     

猪伪狂犬病病毒LA株的分离鉴定

从辽宁省某猪场大批死亡的新生仔猪脑及内脏中分离到多株病毒 ,通过初步验证后选择其中一代表毒株进行了鉴定。该病毒株在PK -1 5细胞上连续传 1 2代均出现典型的细胞病变 ,用适应PK -1 5细胞的病毒接种Vero细胞、猪肾传代细胞IBRS -2及SPF鸡胚成纤维细胞均出现典型的细胞病变。在电镜下可见到典型的伪狂犬病病毒粒子。该病毒对氯仿、乙醚敏感 ,在pH5 0～ 9 0下稳定 ,5 6℃ 3 0分钟即可灭活该病毒。该病毒能被伪狂犬病病毒标准阳性血清中和。取处理后的病料上清液和传代病毒接种家兔均出现典型的伪狂犬病症状。用所分离病毒提取的DNA及培养病毒液经简单的预处理后作为模板 ,应用特异性引物进行PCR能扩增出伪狂犬病病毒 1 2 40bp的gD基因的特异性片段。结果表明 ,所分离病毒为伪狂犬病病毒 ,并将该毒株命名为猪伪狂犬病病毒LA株。     

猪伪狂犬病病毒新W株的分离与鉴定

从新疆五家渠、石河子某猪场病死仔猪的大脑和内脏组织中分离到一株疑为猪伪狂犬病病毒 ( PRV)毒株 ,通过兔体接种、BHK-2 1细胞培养、理化特性测定、中和试验、实验兔和仔猪回归试验、电镜观察、PCR扩增及感染力测定 ,分离的病毒接种实验兔后发生奇痒并麻痹致死 ;BHK-2 1细胞培养盲传 4代出现典型细胞病变 ;电镜观察可见病毒粒子呈圆形并带有囊膜和纤突 ;回归兔出现典型奇痒症状 ,仔猪出现典型的症状和病理变化 ;分离的病毒能被 PR鄂 A株标准阳性血清中和 ;该病毒对氯仿、乙醚、酸、热敏感 ;PCR体外扩增可见其与鄂 A株在同一水平位置上有相同的电泳带 ;用 BHK-2 1细胞测定其毒价 TCID50 为 10 -1 0 .87/0 .1m L 根据此分离病毒株的上述特性 ,鉴定其为伪狂犬病病毒     

猪伪狂犬病病毒NP株的分离鉴定

2013年下半年,福建某免疫接种过猪伪狂犬病疫苗(Bartha)的规模化猪场大批妊娠母猪发生流产、新生仔猪发生共济失调的神经症状,疑似为猪伪狂犬病病毒感染发病症状,为确定发病原因,从该猪场疑似伪狂犬病病毒感染的仔猪脑、肝脏和肺脏中分离到一株未知病毒,PCR检测及测序比对鉴定为猪伪狂犬病病毒,并将分离的病毒命名为NP株。用Reed-Muench法测定分离株病毒的组织细胞半数感染量(TCID50)为10-9.13/0.1mL,动物攻毒试验出现猪伪狂犬病病毒感染的典型症状。试验结果表明,成功分离到一株猪伪狂犬病病毒毒株,为研究福建省猪群伪狂犬病病毒分子流行病学奠定基础。     

猪伪狂犬病病毒HDDJ株的分离鉴定

广东省某猪场常规免疫猪伪狂犬病疫苗(Bartha-K61株)的母猪流产,疑似为猪伪狂犬病病毒感染。为确定发病原因,将流产胎儿的脑、淋巴结、肺脏研磨混合液接种Vero细胞,形成稳定细胞病变(CPE),并测定其细胞半数感染量(TCID50),通过PCR鉴定、测序比对、进化树分析,确定感染病毒及基因型,动物回归实验判定病毒致病性。结果表明,分离毒株为PRV中国变异株,命名为HDDJ株,与猪伪狂犬病疫苗Bartha-K61株亲缘关系较远。     

猪伪狂犬病病毒JL株的分离与鉴定

猪伪狂犬病病毒ＪＬ株的分离与鉴定娄高明韩文瑜张玉静赵建军邹啸环（中国人民解放军农牧大学长春１３００６２）伪狂犬病（ＰＲ）是由疱疹病毒科α疱诊病毒亚科猪疱疹病毒Ｉ型引起的一种以发热、脑脊髓炎为主要症状的急性传染病［１］。猪是本病的主要宿主和带毒者。本病...     

猪伪狂犬病病毒北京株的分离鉴定

从北京某猪场疑似猪伪狂犬病发病死亡仔猪脑及内脏中分离到1株病毒并进行了鉴定。该分离毒株接种ST细胞24 h后出现圆缩、聚集、脱落等典型的细胞病变(CPE);分离毒株能够被伪狂犬病病毒标准阳性血清中和;分离病毒接种家兔后,引起家兔出现奇痒等典型的伪狂犬病临床症状;同时根据GenBank公布的PRV的gD基因设计引物并扩增出特异性的目的片段,扩增产物经过测序比较,表明扩增产物序列为猪伪狂犬病病毒基因序列。以上结果证实该病毒为猪伪狂犬病病毒,依据分离地点命名为猪伪狂犬病病毒北京株。     

猪伪狂犬病病毒LA株的分离鉴定

从辽宁省某猪场大批死亡的新生仔猪脑及内脏中分离到多株病毒，通过初步验证后选择其中一代表毒株进行了鉴定。该病毒株在PK-15细胞上连续传12代均出现典型的细胞病变，用适应PK-15细胞的病毒接种Veto细胞、猪肾传代细胞IBRS-2及SPF鸡胚成纤维细胞均出现典型的细胞病变。在电镜下可见到典型的伪狂犬病病毒粒子。该病毒对氯仿、乙醚敏感，在pH5．0-9．0下稳定，56℃30分钟即可灭活该病毒。该病毒能被伪狂犬病病毒标准阳性．血清中和。取处理后的病料上清液和传代病毒接种家兔均出现典型的伪狂犬病症状。用所分离病毒提取的DNA及培养病毒液经简单的预处理后作为模板，应用特异性引物进行PCR能扩增出伪狂犬病病毒1240bp的gD基因的特异性片段。结果表明，所分离病毒为伪狂犬病病毒，并将该毒株命名为猪伪狂犬病病毒IA株。     

猪伪狂犬病病毒LX株的分离与鉴定

从辽宁某猪场采集病料,经处理后接种BHK-21细胞进行猪伪狂犬病病毒(pseudorabies virus,PRV)分离,结果有2份病料在该细胞上盲传后可见典型的CPE,经测定其毒价为10^-7.8 TCID₅₀/mL。间接免疫荧光试验可见黄绿色荧光,用电镜对纯化的病毒进行观察,可见有囊膜包裹的圆形病毒粒子,直径为140~200 nm。该病毒对氯仿、乙醚、酸和热敏感。对有CPE的细胞培养物进行RT-PCR,结果为阳性。接种试验动物出现典型的猪伪狂犬病临床症状且死亡。结果表明,成功分离到1株PRV。     

猪伪狂犬病病毒四川株的分离鉴定及UL43基因序列分析

从四川某猪场发病仔猪体内分离到1株病毒,该毒株能在Vero、MDBK、PK15、ST、MDCK、BHK21、Marc145、鸡胚成纤维细胞(CEF)上增殖并产生细胞病变。通过蚀斑克隆对其进行纯化,克隆毒株在Vero细胞上为3.0×107TC ID50/0.1mL。该病毒在Vero细胞上连传15代,其TCID50变化很小。病毒对5-溴脱氧尿核苷、氯仿敏感。用该病毒接种家兔和仔猪均出现典型的伪狂犬病症状,gE-ELISA检测接种分离毒的仔猪血清,伪狂犬病毒(PRV)抗体阳性。电镜观察可见直径110～140 nm的典型疱疹病毒粒子。上述结果表明分离株为PRV,并命名为SE株。根据已发表的UL43序列设计1对引物,以分离毒株基因组DNA为模板进行PCR扩增,对目的产物进行克隆及测序分析,结果与GenBank收录的其他PRV毒株(Becker、Ea)的UL43核苷酸序列同源性为98.8%,氨基酸同源性分别为95.2%、97.3%。     

猪伪狂犬病病毒的分离与鉴定

猪伪狂犬病是由疱疹病毒科的猪疱疹病毒1型病毒引起的一种急性传染病，多数动物均可感染，猪是本病的主要宿主和带毒者。本病主要以成年妊娠母猪流产、死产、木乃伊胎、新生仔猪急性死亡及3周龄以内的仔猪表现神经症状为主要特征。近年来我国也相继有本病发生的报道。1997年10月黑龙江省牡丹江地区某养猪场从外地引进种母猪，回来后直接放入后备猪舍与其他后备母猪混养，5日后同舍母猪出现厌食、发热、精神沉郁，有的呕吐、咳嗽。     

猪伪狂犬病病毒的分离鉴定与防制

从福清海口某猪场病猪淋巴结分离到1株病毒。该病毒接种Balb/c小鼠出现神经症状,死亡率为100%;接种Vero细胞出现拉网病变;PRV阳性血清能特异性中和该分离毒。以上结果证实该病毒为猪伪狂犬病毒。确诊后采取隔离、消毒及注射疫苗等措施,取得了一定的效果。     

Shedding patterns in swine of virulent and attenuated pseudorabies virus

Shedding patterns of 2 virulent (P-2208 and KC-152-D) and 1 attenuated (BUK) strains of pseudorabies virus (PRV) were determined in groups of intranasally inoculated feeder pigs. Clinical signs observed following inoculation with the P-2208 and KC-152-D strains included increase in rectal temperatures up to 42.2 C, anorexia, severe respiratory disturbance, and fatal CNS signs in 2 cases. Clinical signs in pigs inoculated with 7.2 X 10(7) median tissue culture infective dose (TCID50) of the BUK strain were limited to depression and a rise in rectal temperatures to 40.5 C for 3 to 4 days. Evaluation of the efficacy of the virus isolation method used showed that the presence on swabs of only 12.5 TCID50 of the P-2208 strain or 8.4 TCID50 of the BUK strain resulted in a 50% chance of virus recovery. Intranasal inoculations with 500 TCID50 of the P-2208 or KC-152-D strain did not result in synchronous infection of the whole group. Intranasal inoculations with 5,000 TCID50 of the KC-152-D strain or 50,000 TCID50 of the P-2208 strain resulted in continuous virus shedding in all pigs between postinoculation days (PID) 4 and 13 (KC-152-D strain) or 14 (P-2208 strain). Some of the pigs in these 2 groups further shed the P-2208 or KC-152-D strain in a continuous or discontinuous pattern up to PID 19 (P-2208 strain) or 20 (KC-152-D strain). The time of onset or the level of virus neutralizing antibody production in individual pigs was not found to have an influence on their shedding patterns.(ABSTRACT TRUNCATED AT 250 WORDS)     

Latent infection and subsequent reactivation of pseudorabies virus in swine exposed to pseudorabies virus while nursing immune dams

The ability of pseudorabies virus (PRV) to infect and establish latency in pigs with passively acquired (maternal) antibody for PRV was tested by exposing such pigs to the virus and subsequently attempting to reactivate latent virus by administering large doses of dexamethasone. Pigs of each of 4 litters that had nursed gilts with relatively high (512, gilts 1 and 2), moderate (32, gilt 3), and no (less than 2, gilt 4) serum titers of virus-neutralizing (VN) antibodies for PRV were allotted to 3 treatment groups (A, B, C) when they were 2 weeks old. Group-A pigs were separated from littermates and dam and thereafter kept in isolation; group-B pigs were experimentally exposed oronasally to PRV and 1 hour later returned to their dam; group-C pigs were kept with their dam and potentially exposed to PRV by contact with littermates of group B. Sera obtained from pigs at selected intervals until they were 17 weeks old were tested for VN activity and for precipitating activity for radiolabeled viral proteins. All group-A pigs remained clinically normal throughout the experiment. Depending on the initial amount of passively acquired antibody, little or no serum VN or precipitating activity remained by the time these pigs were 17 weeks old. Group-B and -C pigs, with relatively high amounts of passively acquired antibody when exposed to PRV, also remained clinically normal. However, most became latently infected as subsequently evidenced by either dexamethasone-induced or noninduced virus reactivation. Noninduced reactivation may have been initiated by weaning the pigs when they were about 8 weeks old.(ABSTRACT TRUNCATED AT 250 WORDS)     

PRV变异株的分离及抗原差异性分析

2011年以来,我国多个省份免疫过伪狂犬病疫苗的规模化猪场发生新生仔猪出现神经症状和死亡的现象,并已确定为猪伪狂犬病病毒(pseudorabies virus,PRV)变异株感染所引起。为探究现PRV流行株特性,2014年下半年以来,我们从免疫过伪狂犬疫苗却暴发伪狂犬病的猪场分离到3株伪狂犬病病毒(分别为XP,QJ,LY株),并对其gE、gB、gC全基因进行测序和序列分析,序列比对结果显示,3株PRV分离株与2012年后分离毒株有较高的同源性;进化树分析显示,3株PRV分离株的gE基因与2012年后分离毒株处在同一进化树分支上,而gB、gC则分别形成了独立的小分支,但仍处在同一较大分支上。我们对当地广泛使用的疫苗株HB-98和Bartha-K61活疫苗免疫血清与Ea,HNX株以及3株PRV分离株进行中和试验,结果显示,HB-98和Bartha-K61活疫苗免疫血清对早期分离株Ea株的中和能力高于HNX、XP、QJ、LY株,但在NX、XP、QJ、LY株之间无明显差异,表明3株PRV分离株的抗原性与2012年后分离毒株无明显差异,而与传统毒株Ea株的抗原性存在一定差异。     

Vaccination of swine with thymidine kinase-deficient mutants of pseudorabies virus

A mutant of pseudorabies virus (PRV) deficient in thymidine kinase (TK-) activity was isolated and characterized. The mutant grew well in cell culture and did not revert to the thymidine kinase-positive phenotype. The PRV-TK- was not virulent when inoculated intranasally into 3-to 4-week-old pigs and could not be reactivated from the ganglia of these pigs by explantation and cocultivation with susceptible cells several weeks after virus inoculation. Pigs that had been exposed to PRV-TK- were immune to challenge exposure with a virulent strain of PRV. Furthermore, the challenge virus was not recovered from the ganglia of most of these pigs, indicating that colonization of the ganglia by a super-infecting virulent PRV strain was considerably reduced by vaccination.     

Factors associated with circulation of pseudorabies virus within swine herds

Data were collected from 104 Minnesota swine farms quarantined for pseudorabies virus (PRV) infection. Each herd was serologically evaluated for the presence of antibodies to PRV in finishing pigs. Herd management practices, swine housing design, and disease profiles were described for each farm. Multiple logistic regression analysis was used to determine which factors were associated with circulation of PRV in the finishing pigs of farrow-to-finish farms. Sixty-seven (64%) of the herds had no serologic evidence of PRV circulation in the finishing section, whereas 37 herds (36%) contained at least one PRV seropositive finishing pig. The odds of a given finishing herd being seropositive for PRV were 2.85 times higher if the finishing pigs were housed in confinement (P = 0.01), 2 times higher if Actinobacillus (Haemophilus) pleuropneumoniae was a clinical problem in the herd (P = 0.03), 1.36 times less for each year that passed since the herd quarantine was issued (P = 0.01), 1.74 times higher if clinical signs of PRV were reported (P = 0.04), and 1.52 times higher if animal protein was included in at least one of the rations (P = 0.08).