再利用鸡毒支原体培养基的研究

液体培养基中的鸡毒支原体收获后，重新调节其ｐＨ，使之恢复到培养前的状态，并继续培养鸡毒支原体。结果表明，这不但能提高单位培养基中的鸡毒支原体产量，而且收获的支原体还能保持较好的抗原性。     

广西鸡毒支原体血清学调查

鸡毒支原体（ＭＧ）是引起鸡慢性呼吸道病（ＣＲＤ）的重要病原。其特征是病鸡表现气管罗音、咳嗽、流鼻涕,母鸡产蛋下降,生产性能降低。是危害养鸡业发展的重要传染病之一。为了搞清广西鸡群中鸡毒支原体的感染情况,我们采用了鸡毒支原体血清快速平板凝集方法,检查了...     

混合感染中鸡毒支原体和副鸡嗜血杆菌的分离鉴定

从冀南地区某养鸡场患呼吸道疾病的病鸡群采集5份样品（气管和眶下窦分泌物）中，同时分离到鸡毒支原体和副鸡嗜血杆菌两种病原体。通过病原的分离培养、细菌L型检验、生化试验、血清学试验等鉴定，证明分离的鸡毒支原体与国际标准株S6的血清型一致，副鸡嗜血杆菌的血清型为A型，动物试验表明，分离的鸡毒支原体和副鸡嗜血杆菌均具有明显的致病性，说明该病鸡群同时混合感染了鸡毒支原体和副鸡嗜血杆菌。     

鸡毒支原体SC克隆致弱株免疫原性测试—开放动物模型的建立？…

对罗斯鸡和ＳＰＦ来航鸡用鸡毒支原体强毒攻击时，以鸡致病性大肠杆菌Ｏ７８血清型菌株１６小时培养物０．２ｍｇ／羽皮下注射作人工诱导发病，试验鸡出现明显气囊病变，初步建立了以鸡致病性大肠杆菌为诱导因子的ＭＧ野外环境人工发病的动物模型。     

如何挑出低产鸡和假产鸡？

《中国家禽》编辑部：我是河北一养鸡户，饲养蛋鸡5年，现饲养蛋鸡5000只。几年来，鸡群产量率达不到标准。如何挑出低产鸡和假产鸡，书本中也说要挑出低产鸡和假产鸡，但总是做不好，望指点迷津。 河北　陈育红杜专家答：先说说低产鸡是怎样产生的： 低产鸡产生的原因，首先是鸡在育成阶段，未能经常注意调整鸡群强弱分群饲养，因而弱鸡生长发育更加受阻；其二是忽视了限制饲喂方法，使部分蛋鸡超重而低产。其三是光照不足或过长，光照不足使蛋鸡推迟开产，过早超长光照使鸡性成熟过早；提前开产造成早衰。另外，部分鸡由于生殖系统和其他…     

鸡毒支原体弱毒培养液在2～10℃中活菌滴度的变化

鸡毒支原体弱毒培养液在２～１０℃中活菌滴度的变化李嘉爱广东省生物药厂广州５１０６３０将培养结束后的鸡毒支原体弱毒培养液，立即存放于２～１０℃普通冷库，保存不同时间作活菌滴度测定。结果表明，鸡毒支原体培养液于普通冷库中短期保存，其活菌数没有明显变化。１...     

上海地区鸡毒支原体感染抗体的血清学调查

本研究采集了上海地区规模化蛋鸡场、林地散养鸡场、种山鸡场的健康产蛋鸡群共240份血清,进行了鸡毒支原体感染抗体的ELISA血清学检测。结果显示,规模化蛋鸡场和林地散养蛋鸡场鸡毒支原体感染抗体平均阳性率分别为97.8%和93.3%,两种饲养模式的鸡群鸡毒支原体感染率都很高,两者无显著差别;3个种山鸡场检测结果差异较大,分别为100%、0、30%,说明种山鸡对鸡毒支原体的感染并不普遍;对规模化肉鸡场鸡群鸡毒支原体抗体跟踪结果表明,在65日龄时鸡毒支原体在鸡群中已经存在,65~90日龄期间鸡群普遍感染鸡毒支原体,肉鸡上市前感染抗体阳性率达到94%。结果表明,产蛋鸡群鸡毒支原体感染情况与饲养方式没有相关性,均呈现较高阳性率,种山鸡感染并不普遍,肉鸡群感染鸡毒支原体高峰期在65~90日龄之间,预防鸡毒支原体病的最佳日龄应在30~60日龄之间。     

鸡减蛋综合征的研究Ⅱ.鸡减蛋综合征病原的分离和鉴定

用某鸡场发生减蛋综合征病鸡的输卵管组织接种１０－１２日龄鸭胚盲传，分离到一株ＥＤＳ－７６·ＥＸＫ２病毒。自第３代起至第１０代，均从鸭胚尿囊液中检出血凝素，凝集鸡红细胞的特性可被ＥＤＳ－７６阳性血清所抑制。鸭胚分离毒不能凝集免红细胞。应用第３和第４代鸭胚尿囊液混合毒经口腔、鼻腔和眼途径人工感染健康产蛋鸡，成功地复制了ＥＤＳ－７６。攻毒后３５天内１１只试验鸡的总产蛋数无明显变化，产蛋率为８５～９４％，     

鸡毒支原体PCR试剂盒对人工感染SPF鸡的检测

鸡毒支原体(MG)是鸡及其他禽类呼吸道疾病的主要病原体，感染鸡群常出现呼吸罗音、咳嗽、流鼻液等。本病在世界各国广泛存在，在鸡群中的感染率很高。我们在广西不同地区鸡场调查中发现，鸡群MG平均感染率达56．9％。感染本病的鸡群由于产蛋下降、生产性能低下和肉鸡胴体品质下降等，给养     

提高鸡法氏囊病双价弱毒苗效价的经验

我厂１９９３年开始，引进生产鸡传染性法氏囊炎ＢＤ５、Ｄ７８双价弱毒疫苗，此苗能够保护鸡群不受鸡传染性法氏囊炎病毒多种血清亚型毒株的感染，从而达到比一般单价疫苗更好的防疫效果。在疫苗的试产中，经过一段时间的摸索总结，改进了部分生产环节，提高并稳定了效价，现将经验介绍如下。１生产原料：１．１种毒：哈兽研提供的ＩＢＤＶ的ＢＤ５与Ｄ７８株。１．２鸡胚：本厂自繁自养的鸡所产种蛋孵化。１．３小牛血清：杭州《四季青》牌犊牛血清。２生产步骤：细胞制备、培养、接毒及收毒均按常规方法进行。３生产条件的选择与改进：３…     

Aujeszky's disease in horses fulfils Koch's postulates

Aujeszky's disease virus was isolated from the brain of a horse which had shown severe neurological signs, including excessive sweating, muscle tremors and periods of mania. Pathological examination revealed a non-suppurative meningoencephalitis. The virus was propagated in cell culture and inoculated into the conjunctiva and nostrils of two ponies. The ponies developed fever seven days after inoculation and subsequently started to behave abnormally, showing severe neurological signs on the ninth day after inoculation. One pony became excited and the other was depressed. One pony died on the ninth day after inoculation and the other was euthanased on the 10th day. Both ponies had a significant increase in serum antibody titre against the virus. The virus was recovered from several parts of the brains and the eyes of the ponies. Aujeszky's disease in horses therefore fulfils Koch's postulates. Although horses do not appear to be very susceptible to the virus, Aujeszky's disease should be included in the differential diagnosis of horses with fatal or transient neurological signs of disease in areas where the virus is endemic.     

Superneutralization test--a new virus serology examination procedure]

The serum neutralisation test, based on the antigen-antibody reaction and cytopathic action of a given virus upon certain in-vitro cultured cell systems, was expanded to the dimensions of a super-neutralisation test by including specific control sera with known titre and applying then to all samples positive to serum neutralisation through repeated addition of virus to tubular cell cultures with no CPE in the serum neutralisation test. Another antigen-antibody reaction was introduced by repeated addition of virus. In samples with less antibody (lower titre) due to lacking or partial neutralisation of added virus such reaction gave a CPE of with the intensity was inversely proportional to the titre. The CPE (cytopathic effect) will disappear beyond a certain titre limit owing to complete neutralisation of added virus. The point of disappearance can be controlled to the purpose of the given test by appropriate choice of the virus dose. This approach will entail negligible extra expenses but enable, in addition to qualitative assessment of reagents, quantitative identification of their antibody titres, and this will, no doubt, add to the informative weight of the test result. The advent of the super-neutralisation test has added to laboratory diagnosis in the field of virus serology a conventiently applicable, uninvolved, and highly effective technique.     

Physical and biological properties of nairobi sheep disease virus

Thermal and pH stability of Nairobi sheep disease (NSD) virus were studied. The 180th mouse brain passage lost infectivity at a higher rate than “wild” virus at 4°C. At 37°C and neutral pH, “wild” virus again was more stable than cell culture and mouse brain attenuated strains with half-life periods of 104, 87 and 51 min, respectively. At 0°C the cell culture attenuated virus was most stable at pH 7.4 with an estimated half-life of 164 h. The density of the virus in sucrose gradients came to 1.195 g vm^?3.Metabolic growth inhibition studies using a halogenated nucleoside, and staining of RNase and DNase-treated infected cell cultures with acridine orange, indicated that NSD virus has a single stranded RNA genome. The growth of the cell culture adapted virus was assayed in monolayers of BHK21/13 cells at low multiplicity of infection. Cell-associated virus (CAV) was first detected at 6 h post-inoculation (PI). The titre increased rapidly until CPE appeared at 48 h and declined after 72 h PI. Cell-free virus (CFV) was first detected at 10 h PI. The titre of CFV increased up to 72 h, but on average was two log units less than the CAV titre.     

鸡传染性支气管炎H120细胞活疫苗规模化生产的研究

通过近两年时间的试验,摸索出并掌握了利用转瓶培养鸡传支H120细胞弱毒的关键技术,利用转瓶机成功生产出鸡传支H120细胞弱毒活疫苗三批,依照<中华人民共和国兽用生物制品质量标准>,经物理性状、无菌、支原体、特异性、外源病毒及安全检验均合格,EID50平均值分别为6.93、6.71和6.82,免疫保护率均达87%以上.     

Effect of KLP-602 on virus replication in cell cultures

The effect of KLP-602 (active substance: lysozyme dimer) on the replication of two animal viruses: the TK900 strain of Aujeszky's disease virus and the Roakin strain of the Newcastle disease virus were investigated. The maximal tolerable dose of the drug was determined for two cell cultures (CECC and GMK) and the effect of the medicine on the titre range of infectious viruses and their adsorption was assayed. The direct impact of KLP-602 on the viral strains used was also determined. And finally the replication dynamics of viruses in the presence of KLP-602 preparation was estimated. KLP-602 showed no direct effect on either the viruses applied in the study or their adsorption. The drug, introduced into the culture 24 hours before its infection, did not affect the replication of the pseudorabies virus, but decreased the titre of the Newcastle disease virus. KLP-602 introduced simultaneously with the infection considerably lowered the final titres of both viruses. The medicine had the greatest inhibitory effect on the replication dynamics of both types of viruses in the CECC and of the pseudorabies virus in the GMK culture upon the maximal tolerable concentrations of drug and low infectious doses of viruses applied.     

稳定表达山羊SLAM受体的Vero细胞系的建立

信号淋巴激活分子（signalling lymphocyte activation molecule, SLAM）又称CD150,是小反刍兽疫病毒（peste des petits ruminants virus, PPRV）和犬瘟热病毒（canine distemper virus, CDV）等麻疹病毒属病毒感染淋巴细胞的主要受体,在病毒侵入细胞中发挥着重要作用。为了建立稳定表达山羊SLAM真核细胞系,本研究将全基因合成的gSLAM基因克隆至真核表达质粒pIRES2-GFP中,构建了重组质粒pIRES2-gSLAM。将该重组质粒转染非洲绿猴肾细胞（Vero）,经G418筛选后,筛选到稳定表达gSLAM基因的细胞系Vero-gSLAM,该细胞系在传代至第10代,仍能稳定表达gSLAM基因,PPRV N75/1病毒株可以感染且能形成明显的细胞病变（CPE）,相比在Vero细胞上10^-4.65 TCID₅₀/0.1 mL的毒价,在Vero-gSLAM上为10^-5.75 TCID₅₀/0.1 mL,其毒价有所提高。该细胞系可用于PPRV强毒分离和致弱机制等相关研究。     

Establishment of Vero Cell Line Expressing Goat SLAM Receptor Stably

Signalling lymphocyte activation molecule (SLAM,also called CD150) serves as a main cell receptor for PPRV (peste des petits ruminants virus).This study was aimed to establish a cell line,using Vero cells as the parental cell,to express goat SLAM stably,which could be used to isolate and propagate PPRV.The gene encoding goat SLAM in vitro was synthesized and cloned into eukaryotic expression vector pIRES2-GFP,and the recombinant expression plasmid pIRES2-gSLAM was obtained.The positive stably transfectant Vero-gSLAM cells were screened by G418 and identified by immunofluorescence(IF) and RT-PCR.The result of virus titration by Vero-gSLAM cell line showed that PPRV strain N75/1 had a titre of 10^-4.65 TCID₅₀ per 0.1 mL in Vero cell at 5 day after infection and the titre of PPRV N75/1 strain was 10^-5.75 TCID₅₀ per 0.1 mL in Vero-gSLAM cells.The cell line would play an active role in virus isolation,biological characteristics study and vaccine virus production of PPRV.     

Virucidal efficacy of nine commercial disinfectants against porcine circovirus type 2

A number of commercially available disinfectants are commonly used on pig breeding farms and are authorised by the French Agricultural Ministry. However, the efficacy of these disinfectants is unknown with regard to the emergent porcine circovirus type 2 (PCV2). The virucidal efficacy of nine disinfectants was evaluated by testing a suspension of PCV2 isolated in France. The assays were performed at 20 degrees C and the efficacy determined after 30 min contact time between virus and disinfectant. After this time, the mixture was passed through a detoxification column and then diluted to remove compounds toxic to the virus and the porcine kidney cell line. The filtrate was serially diluted and inoculated onto cell culture. The infectivity of PCV2 was determined by an immunoperoxidase monolayer assay. No reduction in PCV2 titre was demonstrated with iodine and phenolic products. Significant PCV2 titre reductions (1.61 log(10)) were noted for the seven other products. For five disinfectants, namely a product composed of potassium monopersulfate, two products comprising a quaternary ammonium with one or three aldehyde(s), sodium hypochlorite, and sodium hydroxide, the concentration that significantly reduced the PCV2 titre was equal or 1.5-4 times lower than the authorised use concentration. Only two disinfectants, one composed of potassium monopersulfate, the other containing peracetic acid with hydrogen peroxide, reduced the PCV2 titre with a product concentration at best equal or two times higher than the authorised use concentration.     

Replication of bovine respiratory syncytial virus in bovine and ovine peripheral blood lymphocytes and monocytes and monocytic cell lines

The present study compared the replication of bovine respiratory syncytial virus (BRSV) in bovine and ovine peripheral blood mononuclear cells, ovine and bovine monocytic cell lines and ovine alveolar macrophages. Low titres of virus were detected in ovine and bovine lymphocytes and monocytes 24–96 h post-exposure to the virus but there was no apparent replication of the virus in ovine alveolar macrophages during the culture period. The virus replicated to higher but statistically insignificant titres in ovine and bovine peripheral blood monocytes than in lymphocytes, with lymphocytes yielding peak titres significantly earlier. The secondary cell lines obtained from ovine liver and bone marrow also supported the replication of BRSV to high titres. The titres of BRSV in ovine and bovine lymphocytes and monocytes were significantly lower than in secondary cell lines. The addition of human recombinant tumour necrosis factor alpha after exposure to the virus or pre-incubation of ovine or bovine monocytic cells with either human recombinant interleukin 2 or phorbol myristate acetate before exposure to BRSV, did not significantly affect virus titre. Pre-incubation of cells with indomethacin or actinomycin significantly lowered virus titre (p<0.05).     

In vitro effects of some steroidal hormones on the replication of avian pneumovirus

The effects of testosterone, oestradiol, progesterone and cortisone on the in vitro replication of avian pneumovirus in tracheal organ cultures (TOC) were investigated. Samples of cell-associated and cell-free virus from TOC, grown in medium containing these hormones, were taken at selected intervals. Progesterone and cortisone caused a slight increase in cell-associated virus. Testosterone and oestradiol caused a slight delay and decrease in virus replication when compared with the controls. All groups shared the same time interval to reach peak cell-free virus titre, 96 h post inoculation. In comparison with the controls, only a small drop (0.25-0.50 log10) in the peak of virus titre was observed in the hormone treated groups.