二乙烯亚胺对猪伪狂犬病病毒灭活效果研究

为研究二乙烯亚胺(BEI)对猪伪狂犬病病毒的灭活效果,使用终浓度为0.03%、0.04%和0.05%的BEI在30℃条件下对猪伪狂犬病病毒(DQ株)进行了灭活试验,通过ST传代细胞接种法观察病毒的灭活效果,用2~2.5 kg大耳白兔和断奶仔猪检测BEI灭活后的病毒液所制备疫苗的安全性,用小鼠检测该灭活工艺制备疫苗的免疫效果,并与传统甲醛灭活进行了比较。结果表明,终浓度为0.05%的BEI在30℃情况下经24 h即可彻底灭活PRV病毒;BEI灭活的病毒制备的疫苗接种大耳白兔和猪的安全性良好,免疫小鼠较甲醛灭活病毒能提供更高的保护率。本研究可为猪伪狂犬病灭活疫苗灭活工艺研究提供依据。     

猪细小病毒血凝抑制试验抗原、阳性血清与阴性血清的制备与鉴定

猪细小病毒（Porcine Parvovirus,PPV）血凝抑制试验抗原、阳性血清和阴性血清在猪细小病毒制品的效力检验中不可或缺,对猪细小病毒相关生物制品的质量控制至关重要。试验采用PPV 7909株病毒同步接种PK-15细胞制备血凝抑制试验抗原,用制备的抗原乳化后免疫豚鼠制备阳性血清,同时用未免疫的阴性豚鼠制备阴性血清。对抗原、阳性血清和阴性血清进行鉴定,结果表明,制备的PPV血凝抑制试验抗原HA效价达1:512;阳性血清HI效价达1:1024;阴性血清HI效价＜1:8,且特异性均良好。利用制备的血凝抑制试验抗原、阳性血清与不同PPV疫苗株的灭活抗原、阳性血清进行交叉反应试验,结果表明,制备的抗原与阳性血清具备良好的血清学交叉反应性,可用于PPV制品的统一评价。     

禽流感病毒BEI灭活疫苗制备与免疫效果

使用浓度为0.1%、0.2%、0.3%、0.4%、0.5%和0.6%的二乙烯亚胺(BEI)37℃灭活禽流感病毒(Re-5株)24h,经灭活效果检测BEI浓度≥0.5%可以完全灭活病毒。0.5%的BEI和0.2%的甲醛灭活禽流感病毒,以相同配方制备疫苗,免疫效力比较研究结果显示,按照规程要求免疫21d后采血HI效价分别为8.35log2和7.66log2,BEI灭活疫苗的抗体水平要高于甲醛灭活疫苗。本研究为禽流感灭活疫苗灭活工艺研究提供了依据。     

四种不同灭活剂对新城疫病毒的灭活效果研究

为探索甲醛、β-丙内酯(BPL)、二乙烯亚胺(BEI)和盐酸聚六亚甲基胍(PHMG)对新城疫病毒(NDV)的最佳灭活条件,试验采用不同浓度梯度的甲醛、BPL、BEI和PHMG对NDV进行不同时间的灭活处理,通过血凝(HA)试验、无菌检验和灭活检验确定灭活效果。结果显示,37℃下,NDV的最佳灭活条件为0.1%～0.2%的甲醛灭活22～24h、0.02%～0.025%的BPL灭活9～10h、2%～3%的PHMG灭活16～20h,该研究为筛选规模化生产ND疫苗所需的理想灭活剂提供了依据。     

猪细小病毒灭活疫苗安全性试验及佐剂的筛选

本研究以猪细小病毒(PPV)现地分离株(BQ)第30代细胞培养毒株作为灭活疫苗研究用种毒,通过优化病毒增殖条件和培养方法,获得较高滴度的病毒传代细胞培养物用于PPV灭活疫苗的制备.PPV细胞培养毒株分别用甲醛和β-丙内酯进行灭活,对2种灭活剂灭活的病毒液分别用国产铝胶佐剂、进口矿物质白油佐剂以及法国赛比克公司的MONTANIDETM ISA 206、ISA15AVG、IMS251CVG 3种佐剂制备10种灭活疫苗,然后分别进行10日龄乳鼠、60日龄仔猪、不同妊娠阶段母猪的安全性试验及成年豚鼠的免疫效果对比试验.通过比较不同灭活疫苗的安全性和对成年豚鼠的免疫效果,初步确认甲醛灭活的病毒液与佐剂ISA15AVG的组合为PPV灭活疫苗的最佳灭活剂和佐剂组合.     

微载体培养ST细胞制备猪细小病毒灭活苗及其免疫原性分析

目的利用微载体规模化培养ST细胞制备猪细小病毒L株灭活疫苗,并检测其免疫原性。方法猪细小病毒L株接种微载体悬浮培养的猪睾丸传代细胞系(ST细胞)后,收获细胞培养液和细胞,经二乙烯亚胺(BEI)溶液灭活后浓缩,加矿物质油佐剂乳化,制备灭活疫苗,经肌肉注射疫苗,免疫后28天采血,测定血清中和抗体效价。结果。微载体规模化培养ST细胞制备猪细小病毒获得病毒毒价较高,经灭活浓缩后制备疫苗免疫豚鼠,获得了较高效价的中和抗体效价。结论利用微载体规模化培养ST细胞成功制备了具有较高免疫原性的猪细小病毒灭活疫苗,为后期灭活疫苗的开发奠定了基础。     

不同方法灭活卵黄抗体的比较试验

为确保提取卵黄抗体的安全性,防止其中混入外源病毒,为此使用了化学药品灭活的方法。试验对不同终浓度的甲醛和二乙烯亚胺(BEI)对卵黄抗体灭活效果进行了比对。将鸡新城疫病毒(NDV)、禽流感病毒(AIV H9型)、禽传染性囊病病毒(IBDV)、减蛋综合征病毒(EDS-76)和禽脑脊髓炎病毒(AEV)分别混入到卵黄抗体中,混合后加入终浓度为0.03%、0.05%、0.1%甲醛和0.02%BEI于室温条件下,灭活24h,从试验结果我们可以看出0.02%BEI和0.03%甲醛只能灭活部分病毒,而0.05%和0.1%甲醛能灭活全部病毒,并且对抗体活性无任何影响。因此,综合以上结果选用0.05%的甲醛进行灭活,保证疫苗的安全性。     

二乙烯亚胺和甲醛对猫杯状病毒灭活效果比较研究

为比较二乙烯亚胺(BEI)和甲醛对猫杯状病毒(FCV)的灭活条件,采用终浓度分别为0.05%、0.1%、0.2%和0.3%的甲醛和终浓度分别为0.5%、1%、2%和3%的BEI在37℃对FCV灭活6、12、24、36、48 h,通过微量滴定法检测灭活病毒滴度变化,于F81细胞盲传3代验证病毒灭活效果,采用巢式PCR和ELISA法检测病毒抗原完整性。结果显示:37℃下作用48 h,1%、2%、3%的BEI和0.05%、0.1%、0.2%、0.3%甲醛均可灭活FCV。本研究结果可为FCV灭活疫苗的灭活工艺研究提供参考。     

两种灭活方法制备的猪肺炎支原体灭活疫苗的免疫效果比较

为对比使用甲醛、二乙烯亚胺（BEI）两种灭活方法制备的猪肺炎支原体灭活疫苗对猪的呼吸道发病率、肺部病变记分、饲料转化率、日增重、以及猪血清抗体水平等指标的影响,将120头健康仔猪随机分成三个试验组和一个对照组,于7、21日龄对试验组的仔猪进行疫苗接种,所有猪于20、50、80及140日龄采血分离血清,检测血清中猪肺炎支原体抗体水平。结果显示,用BEI灭活的疫苗在呼吸道发病率、肺部病变记分、饲料转化率、日增重、以及猪血清抗体水平等各项指标均好于甲醛灭活的疫苗（P<0.05）,与进口疫苗无显著差异。试验表明,使用BEI灭活方法制备的猪肺炎支原体灭活疫苗的免疫效果好。     

新购试验豚鼠猪细小病毒抗体的检测

本实验室长期从事猪细小病毒(porcine parvovirus,PPV)的研究,最近向某实验动物中心购买6只豚鼠准备用于PPV相关试验.在试验之前我们用血凝抑制(hemagglutination inhibition,HI)试验检测这些豚鼠的PPV抗体.经检测发现这6只豚鼠的PPV抗体全部阳性,现将检测情况报告如下.     

Potentiating effect of adjuvants on humoral immunity to porcine parvovirus vaccines in guinea pigs

Fourteen different adjuvants, given either in single or combined form with another compound were compared in guinea pigs for their ability to potentiate humoral immunity to porcine parvovirus (PPV) antigen after 2 vaccinations. Two injections were given, the second 3 weeks following the initial vaccination. Antibody concentrations to PPV in sera from injected animals were measured over a 5-week period by the hemagglutination inhibition test. At the conclusion of the experiment, guinea pigs injected with the following adjuvants and PPV antigen: CP-20 961 (Avridin), 50% aluminum hydroxide gel, ethylene maleic anhydride (EMA), oil and water emulsion (O/W) and dimethyl-dioctadecyl-ammonium bromide (DDA) immunologically responded with high geometric mean HI titers (380, 224 and 427, 602, 512, 1202 respectively), whereas guinea pigs receiving Emulsan, sodium dodecyl sulfate (SDS), L-121, combinations of Emulsan/aluminum hydroxide, SDS/aluminum hydroxide and B. pertussis/aluminum hydroxide responded with low mean titers (54, 64, 18, 27, 11, 64, 14, 20 respectively). Guinea pigs injected with antigen without adjuvant responded weakly with geometric mean titers of 3.3 and 16 for the 2 groups tested. Prior to booster injection, guinea pigs immunized with 13 of the preparations had low (less than 4) or undetectable antibody titers. Antibody titers from guinea pigs receiving DDA adjuvant continued to rise throughout the duration of the experiment and at the conclusion had the highest mean titers of the groups tested (1202). The 2 groups immunized with 50% aluminum hydroxide gel had high mean titers (224, 427), but in both instances there was a wide range of titers within a group evidenced by high standard deviations. In contrast, guinea pigs receiving either DDA, CP-20 961, O/W or EMA had antibody titers within a narrow range and small standard deviation. The significance of aluminum hydroxide gel concentration on immunogenicity is discussed.     

Interepizootic survival of porcine parvovirus

Porcine parvovirus (PPV) was transmitted by direct contact between experimentally infected and susceptible pigs at 1 and 2 weeks, but not at 4, 8, 16, or 25 weeks, after experimental infection. In contrast, PPV was found to remain infectious for at least 14 weeks in uncleaned rooms previously vacated by experimentally infected pigs. These findings suggest that facilities contaminated by secretions and excretions of infected pigs may provide the major means by which PPV survives between episodes of acute infection.     

猪细小病毒灭活苗对后备母猪免疫效果观察

猪细小病毒油佐剂灭活苗对后备母猪免疫后的效果表明，免疫组比不免疫组头胎产活仔提高六点五九个百分点，隐性流产有所控制。从而说明，不论是猪细小病毒阳性猪场还是隐性猪场，都有必要对后备母猪全面开展灭活苗的人工免疫。     

Dog response to inactivated canine parvovirus and feline panleukopenia virus vaccines

Inactivated canine parvovirus (CPV) and inactivated feline panleukopenia virus (FPV) vaccines were evaluated in dogs. Maximal serologic response occurred within 1-2 weeks after vaccination. Antibody titers then declined rapidly to low levels that persisted at least 20 weeks. Immunity to CPV, defined as complete resistance to infection, was correlated with serum antibody titer and did not persist longer than 6 weeks after vaccination with inactivated virus. However, protection against generalized infection was demonstrated 20 weeks after vaccination. In unvaccinated dogs, viremia and generalized infection occurred after oronasal challenge with virulent CPV. In contrast, viral replication was restricted to the intestinal tract and gut-associated lymphoid tissue of vaccinated dogs. Canine parvovirus was inactivated by formalin, beta-propiolactone (BPL), and binary ethylenimine (BEI) in serum-free media; inactivation kinetics were determined. Formalin resulted in a greater loss of viral HA than either BEI of BPL, and antigenicity was correspondingly reduced.     

Investigation of Co-infection of PPV7 and PCV2 and Genetic Variation Analysis for PPV7 Cap Gene in Fujian and Guangdong

【Objective】 To investigate the co-infection situation of Porcine parvovirus (PPV7) and Porcine circovirus type 2 (PCV2)in Fujian and Guangdong, and to understand the molecular genetic characteristics of PPV7 Cap gene.【Method】 The blood sample of 432 infected pigs from 69 pig farms in Fujian and Guangdong were collected to detect PPV7 and PCV2 by PCR.The PPV7 Cap gene of positive samples was cloned and sequenced.The DNAStar software was used to analyze the nucleotide and amino acid sequences of PPV7 Cap gene, and Mega 7.0 software was used to draw the genetic evolution tree.【Result】 The results showed that the positive rate of PPV7 was 21.99% (96/432), the positive rate of farms was 53.62%(37/69), and the positive rate of PCV2 was 54.17% (234/432), and the co-infection rate of PCV2 and PPV7 was 13.43% (58/432).The 17 PPV7 Cap gene sequences were amplified using PCR.Nucleotide homology analysis revealed that the homology of the 17 PPV7 Cap gene sequences was 85.6%-100%, and the homology with reference strains was 85.8%-99.0%.Amino acid sequence comparison analysis revealed that the amino acid homology of the 17 PPV7 Cap protein sequences was 87.6%-100%, and the amino acid homology with reference strains was 82.6%-98.7%.Phylogenetic analysis of Cap gene showed that PPV7 could be divided into five main evolutionary branches of PPV7a-PPV7e, among which 9 isolates belonged to PPV7a subtype, 3 isolates belonged to PPV7b subtype, 4 isolates belong to PPV7c subtype, and only 1 isolates isolates belonged to PPV7e subtype.【Conclusion】 This study indicated that PPV7 was widely prevalent in Fujian and Guangdong regions, and had a high co-infection rate with PCV2, which might be the pathogenic factor of Porcine circovirus associated disease(PCVAD).The genetic diversity of PPV7 isolates was abudant in both regions, and PPV7a was the dominant strain at present.The findings of this study provided theoretical basis and data reference for PPV7 prevention and control and vaccine research.     

Development of hybridization probes on the basis of recombinant DNA to identify porcine parvoviruses and rotaviruses

Porcine parvovirus (PPV) and porcine rotavirus (PRV) infections can be diagnosed, and the diagnosis greatly contributes to their control. For the diagnosis of PPV and PRV of pigs recombinant DNA were obtained which could be used as hybridization probes. Homology between PPV-RNA and cloned cDNA was confirmed, and the ability of plasmid probes to detect PRV was demonstrated. Hybridization with preparations of both PPV-infected cells and purified PPV gave positive reproducible results. The results are useful as an experience for the development of a sandwich hybridization system for PPV detection.     

猪细小病毒病毒样颗粒研究进展

猪细小病毒(PPV)是引起母猪繁殖障碍和仔猪死亡的主要病原,疫苗免疫预防是控制该病的主要手段。由于对生物安全的担心,目前国内使用的疫苗仍以灭活苗为主。病毒样颗粒(VLPs)疫苗以其安全性高、免疫原性好成为各类病毒疫苗研究的热门方向。猪细小病毒病毒样颗粒(PPV-VLPs)是不含PPV DNA的空衣壳结构,由PPV VP2结构蛋白体外自行组装形成,形态上与天然病毒粒子相似,具有很强的免疫原性和生物学活性。论文就VLPs疫苗的免疫机制及PPV-VLPs的组装及其在国内外的研究进行综述,为PPV-VLPs研究提供参考。     

Coinfection by porcine circoviruses and porcine parvovirus in pigs with naturally acquired postweaning multisystemic wasting syndrome.

Postweaning multisystemic wasting syndrome (PMWS) is an emerging disease in swine. Recently, the disease has been reproduced with inocula containing a newly described porcine circovirus (PCV), designated PCV 2, and porcine parvovirus (PPV). In order to determine if these viruses interact in naturally acquired PMWS, affected tissues from field cases were examined by immunohistochemistry (IHC) and polymerase chain reaction (PCR) for PCV 2 and PPV, as well as by PCR for the other recognized porcine circovirus, PCV 1. Porcine circovirus 2 was detected by PCR or IHC in affected fixed or frozen tissues from 69 of 69 cases of PMWS collected over 3 years from 25 farms. Porcine parvovirus was detected in 12 of the same cases, and PCV 1 was detected in 9 of 69; however, an apparent decrease was found in the sensitivity of the PCRs used to detect the latter 2 viruses when fixed tissue from the same cases were compared with the use of frozen tissues. Porcine circovirus 2 was not detected by PCR in affected tissues from 16 age-matched pigs that had Streptococcus suis-associated disease. Electron microscopic examination of plasma pooled from 15 pigs with PMWS revealed the presence of PCV and PPV, whereas these viruses were not observed in pooled plasma from 5 age-matched clinically normal pigs. These results confirm and extend previous findings documenting a consistent association of PCV 2 with PMWS. As well, infection by PPV or PCV 1 or both may be an important cofactor in the pathogenesis of some, but apparently not all, cases of PMWS.     

The Recombinant Nonstructural Polyprotein NS1 of Porcine Parvovirus (PPV) as Diagnostic Antigen in ELISA to Differentiate Infected from Vaccinated Pigs

To differentiate pigs infected with porcine parvovirus (PPV) from those vaccinated with inactivated whole-virus vaccine, an enzyme-linked immunosorbent assay (ELISA) based on detection of a nonstructural polyprotein 1 (NS1) was developed. A threshold of 0.23 optical density units was established and the assayhad high specificity (100), sensitivity (88), accuracy (90) and positive predictive value (100) using haemagglutination inhibition as the standard method. A reproducibility test revealed that the coefficients of variation of sera within-plates and between-run were less than 10%. The assayshowed no cross-reactivitywith antibodies to porcine reproductive respiratorysyndrome virus, pseudorabies virus, foot and mouth disease virus, Actinobacillus pleuropneumoniae, Toxoplasma or Chlamydia. Sera obtained from pigs infected with PPV reacted with recombinant NS1 protein in the ELISA. Sera from pigs vaccinated with inactivated whole virus did not recognize this protein in the ELISA. In contrast, antibodies against PPV whole virus were present in both PPV-infected and vaccinated animals. Serum conversion against NS1 was first detected 10 days after infection and NS1-specific antibodies were detectable up to half a year post infection. In conclusion, the PPV-NS1 ELISA can differentiate PPV-infected versus inactivated PPV-vaccinated pigs and could be applied in disease diagnosis and surveillance.