用乙基环丙沙星重建受大肠杆菌污染的BHK-21细胞

为重建受大肠杆菌污染的BHK-21细胞,本研究采用药物乙基环丙沙星,先测出该药对大肠杆菌的最低抑制浓度(minimum inhibitory concentration,MIC),再测出该药对BHK-21细胞的MIC,从而确定10 mg/L为乙基环丙沙星不影响细胞生长,又能抑制大肠杆菌的安全浓度。然后用含该浓度乙基环丙沙星的MEM生长液,对受污染的BHK-21细胞进行物理、化学相结合的循环处理。经过3次循环处理,再传3代后,确认大肠杆菌污染已经被彻底清除,细胞恢复了健康。此方法为抢救受细菌污染的细胞提供了参考。     

BHK-21细胞不同处理方式对裸鼠致瘤性的影响

为了分析BHK-21细胞对裸鼠致瘤性受何种因素的影响,我们分别用甲醛、二乙烯亚胺(BEI)、β-丙内酯(BPL)进行灭活和在-20℃进行冻融处理的BHK-21细胞接种裸鼠,通过病理组织形态学观察判定其是否存在致肿瘤的特性。结果显示,甲醛、BEI、BPL、冻融2次或3次分别处理的BHK-21细胞接种裸鼠,对裸鼠致瘤率为零。冻融1次的BHK-21细胞和107、105和103个BHK-21细胞分别接种裸鼠,致瘤率为100%。10个BHK-21细胞接种裸鼠,未见成瘤。本次试验表明,裸鼠检测BHK-21细胞致瘤性敏感性为103个细胞;冻融2次、甲醛、BEI、BPL处理,BHK-21细胞均丧失致瘤性;冻融1次不能使BHK-21细胞丧失致瘤性。     

猪鼻支原体抗血清的制备与鉴定

猪鼻支原体(Mycoplasma hyrhinis,Mhr)是猪鼻腔的常在菌。将猪鼻支原体与弗氏佐剂共乳化,免疫新西兰大白兔,获得猪鼻支原体兔抗血清。Western blotting检测其特异性;建立间接ELISA方法检测其抗体效价;将获得的猪鼻支原体兔抗血清分别加入猪鼻支原体和猪肺炎支原体培养物中,进行生长抑制试验。结果显示,制备的猪鼻支原体兔抗血清与猪鼻支原体具有反应原性;抗体效价达1:160 000以上;猪鼻支原体兔抗血清可以显著抑制猪鼻支原体的生长,而对猪肺炎支原体的生长影响较小。本试验结果为鉴定和检测猪鼻支原体提供了方法,也为猪肺炎支原体的分离提供了参考。     

支原体PCR检测方法的建立及初步应用

经过对Genebank鸡滑液支原体、猪肺炎支原体、口腔支原体和猪鼻支原体16S rRNA序列比对,设计了一条通用引物,建立支原体PCR检测方法.该方法敏感、特异、经济、快速,在动物疫苗生产中检测细胞、半成品及成品支原体污染具有较大的应用价值.     

用PCR检测长沙市猪肺炎支原体和猪鼻支原体的感染情况

为对长沙市猪支原体肺炎病原流行病学进行初步调查,用PCR方法对从湖南省长沙市5个县（市、区）205头猪中收集的326份病料（205份猪肺和121份猪鼻拭子）分别进行了猪肺炎支原体和猪鼻支原体检测,并对部分基因进行了序列分析。结果发现,猪肺炎支原体检出率为24.4%（50/205）,猪鼻支原体检出率为22.3%（27/121）;长沙市每个县（市、区）的生猪中均存在这两种支原体,其中长沙县生猪阳性率最高（42.4%和31.5%）;序列分析表明,检测出的基因序列与国内外相关序列有97%～100%的同源性。本试验证实了猪肺炎支原体和猪鼻支原体在长沙市猪场的存在。     

过表达冷诱导RNA结合蛋白对BHK-21细胞增殖的影响

用常规细胞培养法连续传代培养Cirp过表达BHK-21细胞至第8代标记为BHK-21-Cirp△,通过HE染色和扫描电镜对细胞形态观察,用BHK-21-Cirp△和BHK-21-ShCirp分别与BHK-21-GFP进行细胞增殖速度的比较,并绘制96 h增殖曲线计算比生长速率,用流式细胞仪检测各试验细胞周期.HE染色和...     

猪鼻支原体PCR检测方法的建立

采集疑似猪鼻支原体的病猪的肺脏并提取DNA作为模版,根据GenBank的数据库中猪鼻支原体膜蛋白P37的序列设计1对特异性引物,建立猪鼻支原体PCR检测方法。试验结果显示,建立的PCR方法有较强的特异性,为快速准确鉴别猪鼻支原体提供了一个有效的临诊手段,也对药物的使用具有指导意义。     

猪鼻支原体感染的诊治

本文总结了猪鼻支原体感染的诊治,猪鼻支原体在猪群中无处不在,通常情况下猪鼻支原体需要外界的诱因才能导致发病。因此,减少环境中的应激因素和病原能有效防控猪鼻支原体感染。     

山羊痘病毒诱导BHK-21细胞凋亡的检测

为验证山羊痘病毒诱导BHK-21细胞出现凋亡现象的存在,分别采用HE染色、凋亡试剂盒检测、流式细胞仪检测和DNA Ladder检测,对山羊痘病毒感染的BHK[21细胞培养物进行细胞凋亡检测.不同方法检测结果均显示,山羊痘病毒感染BHK-21细胞组相同时间细胞凋亡数明显高于对照组.表明山羊痘病毒可诱导BHK-21细胞发生...     

猪肺炎支原体和猪鼻支原体在屠宰猪呼吸道与血液中的分布

用PCR方法对从湖南省长沙市515头屠宰猪收集的1 204份样品(120份猪鼻拭子、254份猪支气管拭子、515份猪支气管肺泡灌洗液和235份猪肺、80份血液)进行了猪肺炎支原体和猪鼻支原体检测,并对部分PCR产物进行序列分析。结果发现,猪肺炎支原体在猪支气管灌洗液中检出率最高(23.3%,120/515),猪鼻拭子和血液中检出率最低(0);猪鼻支原体在猪鼻拭子中检出率最高(24.3%,125/515),在猪支气管拭子中检出率最低(2.5%,3/120)。序列分析表明:试验的PCR产物与国内已出版的相关序列有97%~100%的同源性。试验探明了猪肺炎支原体和猪鼻支原体在猪呼吸道与血液中的分布情况,为这两种支原体的分离鉴定提供了依据。     

口蹄疫病毒诱导BHK-21细胞产生凋亡的研究

试验利用口蹄疫病毒感染BHK-21细胞,通过MTT法、Hoechst 33258染色、原位末端标记技术(TUNEL)、流式细胞术和链特异性荧光定量RT-PCR,分别就口蹄疫病毒对BHK-21细胞生长的抑制作用、凋亡细胞的形态学和分子生物学特征、凋亡峰的出现和细胞周期的变化以及口蹄疫病毒基因组在BHK-21细胞内的复制情况进行了检测。结果表明:口蹄疫病毒可抑制BHK-21细胞的生长并诱导其产生凋亡,呈现典型的凋亡细胞特征,出现细胞凋亡峰并且细胞周期明显被阻滞在G1/G0期,同时对凋亡率和口蹄疫病毒基因组复制的关系做了初步研究。     

L-ascorbic acid enhances apoptosis in human gastric carcinoma cell line AZ-521 cells infected with Mycoplasma hyorhinis

Mycoplasma hyorhinis (M. hyorhinis) exerts multiple effects on cell metabolisms including apoptosis mediated by their endonucleases and nitric oxide production in vitro. Although AsA is preferable to health in general because of its reactive oxygen species scavenging activity, we found that in a human carcinoma cell line AZ-521 infected with M. hyorhinis, apoptosis was enhanced by addition of L-ascorbic acid (AsA) to the cell cultures. No significant differences were evident between the AZ-521 cells with and without AsA (AsA-) after 24 hr of incubation in the mitochondrial fluorescence. M. hyorhinis-infected AZ-521 cells treated with AsA (AsA +) have developed distinct DNA ladders as compared to the control cells AsA- after 24 hr of incubation. Marked cytopathic effects were rather apparent in AsA-treated cells than in control cells AsA- after 24 hr. Our data demonstrate that AsA addition to cell cultures enhances apoptosis induced by M. hyorhinis infection. We suggest that the presence of another external apoptotic pathway by M. hyorhinis infection.     

稳定表达TIGAR基因的BHK-21细胞系的构建及其对新城疫病毒增殖效果的评价

TP53诱导的糖酵解和凋亡调节因子(TP53-induced glycolysis and apoptosis regulator,TIGAR)是p53下游的靶基因,具有调节糖酵解水平和抗细胞凋亡功能.由于新城疫病毒(NDV)引起细胞死亡是通过诱导凋亡产生,所以提高宿主细胞的抗凋亡水平,有助于延长细胞存活时间进而提高子...     

猪β-干扰素的基因改造表达及其抗猪繁殖与呼吸综合征病毒活性测定

本研究根据GenBank上登录的猪β-干扰素基因成熟肽核苷酸序列(mPoIFNβ),在保持原猪β-干扰素蛋白序列不变的基础上,对猪β-干扰素基因进行了毕赤酵母偏嗜性改造,并构建了毕赤酵母重组表达质粒pPICZαC-PoIFNβ。pPICZαC-PoIFNβ经SacⅠ酶切线性化后,电击转化导入感受态的毕赤酵母菌株X-33中,转化子经YPDS+Zeocin抗性平板筛选和PCR鉴定后获得多株阳性菌株。阳性酵母菌株经甲醇诱导分泌表达了重组PoIFNβ,其表达量约为127.9 mg/L。表达产物经SDS-PAGE和Western blotting检测,结果表明,表达产物为分子质量约25和28 ku的混合物,并且二者都可与PoIFNβ阳性血清结合。以细胞病变抑制法测定重组β-干扰素在BHK-21细胞上的抗水泡性口炎病毒活性为2.8×10³ IU/mL;对猪繁殖与呼吸综合征病毒(PRRSV)在Marc-145细胞上抗病毒活性达到1.6×10³ IU/mL。     

水泡性口炎病毒诱导BHK-21细胞的凋亡

采用HE、Giemsa染色、透射电镜以及DNA琼脂糖凝胶电泳等研究了水泡性口炎病毒（VSV）诱导BHK-21细胞凋亡的过程。结果显示：VSV感染BHK-21细胞后,光镜下可见细胞圆缩,细胞器固缩、核仁消失、染色质凝聚和核碎裂、凋亡小体出现;电镜下观察到染色质聚集形成典型的新月形,胞浆中充满大量空泡,细胞核因染色质凝聚也发生了空泡化;1％的琼脂糖凝胶电泳出现180-200bp整倍数的DNA梯形条带。结果表明,VSV诱导BHK-21细胞凋亡是其致细胞病变的主要表现形式之一。     

Testing the susceptibility of cultured cells to infection with bovine leukemia virus

Different cell cultures were studied for their susceptibility to bovine leucosis virus infection. Syncytial assay was used for this study. The FLS/BLV+ cell line served as virus source. Cell lines BHK-21 and ZP-1/58 were found to be susceptible to syncytium formation. Large cells with one to three large nuclei, and loose nuclei reaching the size of syncytium were observed to occur in the BHK-21 and ZP-1/58 cell lines, apart from the syncytial formations. The virus specificity of the syncytia arising in these two cell lines was confirmed by the immunofluorescence assay. In the case of the immunoperoxidase assay, a positive result was obtained only in the BHK-21 cell line. The occurrence of syncytia and large nuclei was observed even in the cases when the BHK-21 cells were infected with the lymphocytes of leucotic cows.     

稳定表达T7 RNA聚合酶BHK-21细胞株的构建

【目的】通过建立过表达T7 RNA聚合酶(T7 RNA polymerase, T7 RNAP)的慢病毒系统,构建可稳定表达T7 RNAP的BHK-21细胞株。【方法】根据GenBank中公布的大肠杆菌BL21(DE3)基因组中T7 RNAP基因序列(登录号：NZ＿CP081489.1)设计引物,并采用PCR扩增T7 RNAP基因片段,将其克隆至慢病毒载体中,构建pCDH-CMV-T7 RNAP重组质粒。筛选阳性克隆及测序鉴定后,利用脂质体将包含重组质粒pCDH-CMV-T7 RNAP的包装系统和辅助包装质粒共转染至HEK-293T细胞,进行慢病毒的包装及纯化,获得高病毒滴度的重组慢病毒。将收集的病毒液分别以感染复数(multiplicity of infection, MOI)为1、5、10和20感染BHK-21细胞,72 h后观察荧光情况,筛选最佳MOI。将重组慢病毒在最佳MOI条件下感染BHK-21细胞,通过绿色荧光蛋白copGFP的表达观察感染细胞的阳性率。使用4μg/mL嘌呤霉素作为抗性筛选物进行多轮筛选,最终筛选得到BHK-21-T7 RNAP细胞株。进一步对所筛选的细胞株...     

Mycoplasma hyorhinis in Taiwan: diagnosis and isolation of swine pneumonia pathogen

This study attempted to determine whether one multiplex polymerase chain reaction (PCR) is an effective adjunct method for diagnosing Mycoplasma hyopneumoniae and Mycoplasma hyorhinis infection, and whether M. hyorhinis should be considered as an enzootic pneumonia or porcine respiratory disease complex pathogen in Taiwan. To our knowledge, this study is the first to isolate and identify M. hyorhinis as a porcine pathogen in Taiwan. A novel isolation method and a multiplex PCR test were applied to detect and isolate M. hyorhinis. The correlation of M. hyorhinis with swine pneumonia was also examined using a challenge test. Based on weight, 18 pigs were assigned to three groups and housed throughout the study in a specific-pathogen-free (SPF) facility and provided with aseptic feed and water. Groups 1 (n=6) and 2 (n=6) were challenged with 5mL M. hyorhinis culture via tracheal intubation on day 1. The M. hyorhinis strains ATIT-1, -3, and-7 were used to infect group 1 and the strain ATCC 27717 was used for group 2. Culture medium was replaced by phosphate-buffered saline in group 3 (n=6). All pigs were slaughtered on day 28, and their lungs were removed for examination of lesions. Of the six pigs in group 1 challenged with wild-type strains, two had typical mycoplasma pneumonia lesions. No gross lung lesions were observed in groups 2 and 3. Although further examination is necessary to confirm that wild-type strains can cause pneumonia, it appears that M. hyopneumoniae is no longer the only mycoplasma pathogen implicated in the diagnosis of swine enzootic pneumonia (SEP).     

Attachment of Corynebacterium renale to tissue culture cells by the pili.

One or more cells of Corynebacterium renale strains (serologic types, I, II and III), which possessed numerous pili, frequently were attached to BHK-21 cells, primary dog kidney cells, and primary rabbit kidney cells. The percentage of the cultured cells to which C renal cells were attached was about 70%. The percentage was less with cells of C renale possessing fewer pili, around 30%. After C renale was treated with the homologous anti-pili serum, the percentage of BHK-21 cells to which bacterial cells were attached was even less (22%). In electron micrographs, the pili of C renale were observed to attach themselves to the membranes of BHK-21 cells. The adhesive property of the pili of C renale to tissue culture cells was thus demonstrated.