Genome Characterization of a Recombinant Porcine Reproductive and Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome virus (PRRSV) mutates continuously, and it is increasingly difficult to control it. To monitor the genetic evolution characteristics of PRRSV timely under the condition of natural infection, a novel PRRSV variant named SHpd1/2018 was isolated from PRRSV positive clinical samples. The results showed that the SHpd1/2018, with a total genome length of 15 018 bp (excluding poly A), showed similar proliferation characteristics to HP-PRRSV strain HuN4. However, it could not be recognized by the monoclonal antibody against HuN4-Nsp2. The sequence analysis indicated that SHpd1/2018 had the greatest homology with HP-PRRSV-like strains, reaching 94.3% with HuN4 strain. The results of recombination analysis showed that SHpd1/2018 was recombined from HP-PRRSV-like strain (main parent strain) and NADC30 strain (secondary parent strain), and both the two recombination breakpoints nt2002 and nt3205 are located in the hypervariable regions of the Nsp2 gene. In short, we confirmed that the isolated strain SHpd1/2018 is a recombinant PRRSV, which may be the main cause of the disease in the pig farm in Shanghai.     

鸡白血病／肉瘤病毒杂交瘤细胞株的建立及其单抗特性分析

用提纯的RSV-1抗原免疫BALB/C小鼠,将其脾细胞与SP2/0癌细胞进行融合,获得10株能稳定分泌特异性抗体的杂交瘤细胞系。用间接ELISA、IFA、AGP对其生物学特性进行了分析,10株MCA均属小鼠免疫球蛋白IgG_1、R_5C_(21)a、R_5C_(22)a、R_7C(32)、R_7C(34)四株MCA与RAV-1、RAV-2、SR-RSV-A、Pr-RSV-C、RAV-50病毒株均有强交叉反应,其余6株对上述病毒反应情况不尽一致,10株单抗与REV(T株)均无交叉反应。文章还讨论了单克隆抗体在我国SPF鸡群和普通鸡群白血病检测、净化中实际应用的可能性。     

The B and T Cell Responses to Orf Virus Infection of Ovine Skin

Abstract— Local scarification and infection with orf virus induced an influx into the dermis of a significantly greater number of T cells than scarification alone. These cells accumulated underneath the early lesion caused by the scarification and later within epidermal pustules which formed as a result of infection. Cells of the γδ, T₄ and T₈ subsets were all implicated in this response. Dermal B cell numbers also rose in response to infection but relatively fewer B cells were found within pustules. Dendritic cells reactive for IgM were prominent under the initial lesion caused by scarification and dense aggregations occurred under the degenerating epidermis about 72 h after infection. Résumé— L'infection par scarification locale de virus de l'ecthyma contagieux du mouton a provoqué un influx de lymphocytes T dans le derme significativement plus important que lors de scarification seule. Ces cellules s'accumulaient sous les lésions précoces provoquées par la scarification et plus tard au niveau des pustules resultant de l'infection. Les lymphocytes T3, T4 et γδ, étaient impliqués dans cette reaction. Le nombre de lymphocytes B dermiques augmentait aussi en réponse à l'infection, mais peu d'entre eux étaient retrouvér dans les pustules. Les cellules répondant à l'lgM étaient majoritaires sous les seules lésions provoquées par scarification et des agrégations denses apparaissaient sous l'épiderme dégénéré 72 heures aprés l'infection. Zusammenfassung— Die lokale Skarifikation und Infektion mit dem Orf-Virus führte zum Einwandern von einer signifikant größeren Anzahl von T-Zellen in die Dermis, als die Skarifikation allein. Die Zellen akkumulierten sich unter der frühen Skarifikationsläsion und später innerhalb der epidermalen Pusteln, die sich durch die Infektion ergaben. Zellen der Gamma-delta-, T4-und T8-SubpopuIationen waren an dieser Reaktion beteiligt. Auch die Anzahl dermaler B-Zellen stieg als Antwort auf die Infektion, aber innerhalb der Pusteln wurden, relativ gesehen, weniger B-Zellen gefunden. Die auf IgM reaktiven Denritenzellen hoben sich unter der initialen Läsion durch die Skarifikation hervor, dichte Aggregationen fanden sich unter der degenerierenden Epidermis ungefähr 72 Stunden nach der Infektion. Resumen Infección e introducción por medio de multiples punturas cutáneas del virus Orf, produjo un mayor aflujo de linfocitos T en la dermis que punturas de manera aislada. Éstas células se acumularon debajo de la lesión primaria causada por las punturas y de forma tardía en las pústulas epidérmicas, las cuales se formaron como resultado de la infección. Las células del tipo yó de los subgrupos T4 y T8, se encontraron todas implicadas en esta respuesta. Los números de linficitos B en la dermis se vieron aumentados como reacción a la infección, pero menos en las pústulas, relativamente. Células dentríticas reactivas a la IgM fueron prevalentes en la lesión inicial por las multiples punturas, y 72 horas despues de la infección, se detectaron agregaciones densas que ocurrieron bajo la epidermis en degeneración.     

抗马立克氏病新品系选育第四代雏鸡MDV攻毒试验结果

F4雏鸡MDV攻毒试验结果显示,亲本父母代鸡均携带No614血型基因的选育试验组,60日龄死亡率显著低于不经血型基因选育的对照组(P＜0.05);其内脏器官组织肿瘤病变率也低于该对照组,但差异不显著(P＞0.05);选育试验组鸡的肝脏的肿瘤病变率仍显著低于血型基因选育对照组和非选育对照组鸡(P＜0.05).提示No614血型基因具有一定程度的马立克氏病(MD)抗性.     

狐狸脑炎病毒细胞培养灭活疫苗的研究

采用分离到的狐狸脑炎病毒ＦＥＶ－Ｈ作种毒，经ＭＤＣＫ细胞培养，经最终含量为０．２％的甲醛灭活，制备狐狸脑炎病毒细胞培养灭活疫苗。皮下接种疫苗１０ｍｌ，试验狐，貉，犬均无临床特异反应，局部吸收良好。最小免疫剂量为１６倍稀释的疫苗原液１ｍｌ，使用剂量定为４倍稀释的疫苗原液１ｍｌ，试验狐狸免疫后３０天，血清中和抗体效价达到高峰值１：１４５，能耐受张毒攻击。免疫后６个月，抗体水平降至１：３２，但此时仍能耐     

鸡痘病毒282E4弱毒株TK基因限制性酶切图谱分析

以限制性内切酶ＢａｍＨＩ、Ｘｂａｌ、Ｃｌａｌ、Ｈ１ｎｄⅢ、Ｎｃａｌ对含有鸡痘病毒（ＦＰＶ）２８２Ｅ４弱毒株３．７ｋｂＨｉｎｄⅢＴＫ基因片段的重组质粒ｐＳＬ１进行单酶和它们之间双酶酶切。结果表明：３．７ｋｂＨｉｎｄⅢＴＫ基因片段上有２个Ｃｌａｌ切点，２个Ｘｂａｌ切点，１个Ｎｃａｌ切点，没有ＢａｍＨＩ切点。随后，用澳大利亚ＦＰＶ２．２ｋｂＨｉｎｄⅢ＋ＣｌａｌＴＫ基因作探针，对各种酶切片段进行Ｓｏｕｔｈｅｒｎ印迹杂交，进一步确定ＴＫ基因位于２．２ｋｂＨｉｎｄⅢ＋Ｃｌａｌ片段中。杂交结果与限制性酶切图谱分析结果相一致。该基因的限制性酶切图谱与澳大利亚ＦＰＶ疫苗株的基本相同。     

In vitro studies on feline panleucopaenia virus. Standardisation of haemagglutination-inhibition test for feline panleucopaenia virus antibody

Standardised procedure for obtaining reproducible haemagglutination-inhibition results for FPV antibody which correlate with serum-neutralization titres was described. Optimal conditions were found to be Alsevers anticoagulant, PBS/0.05% BSA (pH 6.8) as buffer, especially washed round bottom microplates, determination of maximally sensitive porcine erythrocytes, use of reproducible erythrocyte concentrations, inactivation of serum samples at 56 degrees C for 30 min and serum treatment with koalin pH 9.0. The concentration of erythrocyte used for estimation of haemagglutination units in H1 test should not differ from that used as indicator in the test. Predilution of serum beyond 1:4 associated with false results. Reproducible method for removing natural agglutinins in serum by adsorption with erythrocytes was described.     

Isolation and biological properties of virulent subpopulations from lentogenic Newcastle disease virus strains

From each of two lentogenic Newcastle disease virus (NDV) strains of the type LaSota and Hitchner B1 a virulent subpopulation could be obtained. The two subpopulations were—in comparison to the two parent viruses—more resistant to the lipid solvent chloroform and more stable against thermal degradation. Also, the glycoproteins haemagglutinin and F (fusion) were more stable against thermal inactivation. Electron microscopic observations revealed in terms of size and morphology all of the characteristics of NDV. Both subpopulations possessed, however, the same elution kinetics as their respective parent strains. The intracerebral and intravenous pathogenicity indices as well as the mean death times of the two subpopulations allow to classify these viruses as virulent Newcastle disease viruses.     

Current situation of sharka disease in Ankara,Turkey

Sharka disease has a limited distribution in Turkey and does not present a problem for stone fruit production. However, sharka is the most common virus disease of apricots, plums and peaches in Ankara, although it is not a common disease in other cities in Turkey. In different parts of Ankara, 212 private gardens in 21 locations were surveyed forPlum pox virus (PPV) incidence. All together 935 trees of apricot, plum, peach, sweet cherry and sour cherry were sampled and tested for the presence ofPPV by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA).PPV was identified in numerous trees,viz. 286 apricots, 172 plums and 65 peaches. Strain differentiation ofPPV was accomplished using double-antibody sandwich indirect enzyme-linked immunosorbent assay (DASI-ELISA). These assays confirmed the presence of isolates belonging toPPV-M, PPV-D and mixed infections ofPPV-M+D. This is the first report of the presence ofPPV-D and mixed infections ofPPV-M+D in Turkey. http://www.phytoparasitica.org posting July 14, 2004.     

The epidemiology and diagnosis of bluetongue with particular reference to Corsica

Bluetongue (BT) and/or BT viruses (BTV) have been identified in the Mediterranean basin and the Balkans each year from 1998 to 2002 and in particular BTV serotype 2 in the French Island of Corsica (2000 and 2001). In response to these virus incursions, the French Veterinary Authorities carried out epidemiological studies that included virological, serological and entomological analysis, and two vaccination campaigns performed in the winter of 2000/2001 and the winter and spring of 2001 and 2002. Rapid and reliable serotype differentiation is essential at the start of an outbreak to allow an early selection of vaccine to control the spread of the virus. Thus, molecular tools, that complement conventional methods, have been developed for early detection of infection, determination of the serotype, and differentiation between natural infection and vaccination. Serological results showed that the first vaccination campaign during the winter of 2000/2001 did not provide full protection for all sheep and during the summer of 2001, 335 sheep flocks in Corsica were again infected by BTV 2 (7-fold more that in 2000). Entomological studies have demonstrated that the only proven vector of the disease, Culicoides imicola, was present in the island in 2000 and that it has successfully established itself in Corsica. The safety and immunogenicity of the commercial South African vaccine were studied. Fourteen sheep were vaccinated and then observed for clinical signs. Blood, sera, spleen and lymph nodes were collected and analyzed, and the results confirmed the safety and potency of using this vaccine to protect sheep from clinical disease. As a result, an intensive vaccination campaign was performed during winter and spring 2001/2002. No cases of BT had been observed by the end of summer 2002, indicating that the vaccination campaign has been successful in protecting sheep from infection.