猪胸膜肺炎放线杆菌浊度与细菌计数的关系

为了弄清猪胸膜肺炎放线杆菌生长特性、细菌悬液浊度与细菌计数的关系,从而也为探讨细菌致病机理及指导临床上细菌疫苗的生产等提供参考依据,利用地方流行优势菌株APP-7型,将其于TSB液体培养基中培养14 h,按1 h间隔动态取样,测定菌悬液的浊度值(OD630)并用平板法进行活菌计数。结果表明:细菌在接种后2 h进入对数生长期,并持续约3 h,然后进入稳定期。对细菌浊度和细菌计数进行相关性统计分析,发现两变量间存在着极显著相关(P<0.01),以细菌浊度为X,细菌数为Y,建立了曲线回归方程,即:Y=9.817×1014X5.817。     

IL-17介导山羊传染性胸膜肺炎小鼠模型肺部炎症反应研究

为阐明IL-17等相关炎性因子在山羊传染性胸膜肺炎(Contagious caprine pleuropneumoniae,CCPP)中的作用,将20只6周龄~8周龄SPF雌性Balb/c小鼠随机分成试验组和对照组,每组10只,建立CCPP小鼠模型,按时间点处死小鼠后采集血液和肺组织,进行组织病理学分析和肺部山羊支原体山羊肺炎亚种(Mycoplasma capricolum subsp.capripneumoniae,Mccp)载量检测鉴定模型。应用real-time PCR检测肺部IL-17及其相关细胞因子、趋化因子及其受体的mRNA水平,应用ELISA检测血清和肺组织匀浆上清液中IL-17蛋白水平,应用流式细胞术检测肺组织中中性粒细胞和巨噬细胞数量变化。结果显示,试验组小鼠精神状态不佳,肺部病理损伤严重,Mccp载量为5.9×10^4 copies/μL,与对照组相比有极显著差异(P<0.001);与对照组小鼠相比,试验组小鼠肺组织IL-17相关炎性因子mRNA表达升高,血清和肺组织匀浆上清液中IL-17蛋白水平显著升高(P<0.001,P<0.01),肺部中性粒细胞和巨噬细胞数量极显著增加(P<0.01,P<0.001)。说明成功构建了CCPP小鼠模型,在Mccp诱导小鼠肺部炎症早期,IL-17参与肺部炎症反应。     

S100A12在胸膜肺炎放线杆菌诱导猪肺泡巨噬细胞炎性细胞因子表达及吞噬中的作用

试验旨在探究S100A12在胸膜肺炎放线杆菌（Actinobacillus pleuropneumoniae,APP）诱导猪肺泡巨噬细胞（porcine alveolar macrophages,PAM）炎性细胞因子表达及吞噬中的作用。PAM细胞接种APP菌株后,用实时荧光定量PCR检测感染后不同时间点炎性细胞因子和S100A12的mRNA表达水平;构建S100A12重组蛋白表达载体并进行重组蛋白的表达纯化,用MTT法检测其对PAM的细胞毒性,实时荧光定量PCR检测不同浓度（0、5、50和500 ng/mL） S100A12重组蛋白对PAM炎性细胞因子mRNA表达水平的影响;构建S100A12干扰质粒,用Western blotting、实时荧光定量PCR及流式细胞术检测其干扰效率及其对APP感染PAM后炎性细胞因子mRNA表达水平和细胞凋亡的影响;用平板计数法检测S100A12表达对APP的黏附侵袭及其在PAM细胞内存活的影响。结果表明,APP感染促进PAM中IL-6、IL-8、IL-18、IL-1β和TNF-α等炎性细胞因子表达的同时也促进S100A12的表达,且该表达随APP感染剂量增大及时间的延长均显著或极显著增加（P<0.05;P<0.01）。5、50和500 ng/mL重组蛋白S100A12对PAM均没有毒性。5和50 ng/mL的重组蛋白S100A12均可显著促进PAM中IL-6、IL-8、TNF-α、IL-1β、IL-21和IL-5等炎性细胞因子的表达（P<0.05）,而高浓度的S100A12重组蛋白则对上述炎性细胞因子表达无影响（P>0.05）。干扰质粒可成功阻断S100A12蛋白的表达,与转染shNC的对照组相比,在APP诱导下转染shS100A12干扰质粒的PAM中细胞因子IL-6、IL-8、IL-1β和IL-5的转录水平显著或极显著降低,且细胞凋亡率也显著或极显著增加（P<0.05;P<0.01）。进一步研究发现,干扰PAM中S100A12蛋白的表达可显著增强APP对PAM的黏附侵袭能力及其在PAM内的存活能力（P<0.05）,相反,体外添加S100A12重组蛋白则显著抑制APP对PAM细胞的黏附侵袭及其在PAM内的存活（P<0.05）。以上研究表明,S100A12具有增强APP感染后PAM炎性细胞因子的表达、抑制APP诱导的PAM凋亡和降低APP对PAM的黏附侵袭及其在PAM内存活的作用,为进一步揭示APP感染过程中S100A12对PAM调控作用及机制奠定了基础。     

猪胸膜肺炎放线杆菌外膜脂蛋白基因的原核表达

经PCR从含有OML基因片段的重组质粒App-OML-1中扩增出mAppOML-1基因,同时对目的基因和表达载体pPRoEX HTb进行酶切、连接、转入E.coliBL21,构建重组质粒pPRoAppOML-1.阳性克隆用IPTG进行诱导,经SDS-PAGE电泳鉴定,表达的融合蛋白分子质量约为45 ku,Western-blotting分析表明表达的目的蛋白具有良好的反应原性.     

Emulsifier content and side effects of oil-based adjuvant vaccine in swine

Side effects caused by the excessive emulsifier in oil-based adjuvant vaccine were examined practically in swine using one oil-in-water type adjuvant vaccine against swine pleuropneumonia. The vaccine was prepared from cell-free-antigen of Actinobacillus pleuropneumoniae, liquid paraffin, and several polyoxyethylenesorbitan and sorbitan oleates. Based on findings about safety in mice and emulsion stability, 2 vaccines containing either 11.25% or 6.25% emulsifier content were injected intramuscularly twice in swine, as the highest and lowest limits, respectively, within the practical range. All pigs showed temporary fever and malaise with anorexia for several days after each injection. The fever of the higher emulsifier content group took significantly longer to recover than the lower. Malaise also showed a similar tendency. On the other hand, antibody response was sufficiently induced with no significant difference between the 2 groups. Lowering the emulsifier content is a very simple but effective solution for mitigation of side effects without the reduction of adjuvanticity. For safe and high-quality oil-based adjuvant vaccines, not only antigen and base-oil, but emulsifier content must be optimized.     

A proteomic reference map for pig serum proteins as a prerequisite for diagnostic applications

A reference protein map for pig serum was set up using two-dimensional electrophoresis (2-DE). Thirty-nine protein chains or spots deriving from 26 different proteins were identified by immunological and mass spectrometric methods. Thus, the positions of most medium to higher abundance serum proteins could be determined on the 2-DE gels. The plasma protein fibrinogen was also included in our study. The overall pig protein pattern differs in some respect to serum/plasma maps of other mammalian species, e.g. in levels and properties of single proteins such as haptoglobin or IgM or in species-specific proteins like pig major acute phase protein. Serum protein maps are a useful tool to get an overview on expressed proteins, and to monitor changes in concentration as well as isotype distribution of the identified proteins. As a consequence, more detailed knowledge on protein pattern changes may give deeper insights into the metabolic development of some pathologic conditions and may lead to putative biomarkers for further investigation. Selected examples for protein pattern changes in pigs infected by a viral (porcine circovirus type 2) and a bacterial (Actinobacillus pleuropneumoniae) pathogen illustrate the usefulness of the method.     

胸膜肺炎放线杆菌地方分离株和参考菌株的生物被膜形成

通过玻璃试管和聚苯乙烯微孔板结晶紫染色法分别对胸膜肺炎放线杆菌(APP)的15个血清型国际参考菌株和22个中国地方分离菌株在体外形成生物被膜的能力进行了定性和定量分析.在15个血清型(无14型)的参考菌株中,只有5b、6和11型能在聚苯乙烯微孔板上形成生物被膜;而59%的地方分离株(涵盖13种血清型,无14和15型)在聚苯乙烯微孔板上表现出产生生物被膜的能力.结果表明,大多数血清型的APP能在体外形成生物被膜,尤其在地方分离株中更普遍;与低毒力血清型的菌株相比,高毒力和中等毒力血清型的菌株更倾向于形成生物被膜.     

锦州地区猪传染性胸膜肺炎放线杆菌的分离与鉴定

[目的]调查锦州猪传染胸膜肺炎的流行情况。[方法]从锦州部分发病猪场采集病料5份,通过细菌的分离培养、生化试验、卫星现象观察,溶血试验、CAMP试验、药敏试验和动物接种试验对致病菌进行分离与鉴定。[结果]该病原菌为革兰氏阴性短小杆菌,无芽孢,具有多形性。分离到5株猪传染性胸膜肺炎放线杆菌,均有卫星现象和溶血现象。CAMP试验结果表明,金黄色葡萄球菌可增强其溶血圈。5株分离菌对头孢拉定、先锋V、氟哌酸高度敏感,而对阿莫西林、链霉素、青霉素、金霉素有耐药性。动物接种试验表明该致病菌对家兔具有较高的致病力。[结论]该研究可为猪传染性胸膜肺炎的临床治疗提供依据。     

Evaluation of a single dose versus a divided dose regimen of amoxycillin in treatment of Actinobacillus pleuropneumoniae infection in pigs

The theory of a time-dependent effect of amoxycillin was examined in a model of porcine Actinobacillus pleuropneumoniae (Ap)-infection using clinically relevant dosage regimens. Twenty hours after infection of fourteen pigs, when clinical signs of pneumonia were present, one group of pigs received a single dose of amoxycillin (20 mg/kg, i.m.), whereas another group received four doses of 5 mg/kg injected at 8-h intervals. A similar AUC of the plasma amoxycillin concentration versus time curve was obtained in the two groups, whereas the maximum concentration was threefold higher using the single high dose. Plasma amoxycillin was above the MIC for twice as long using the fractionated dosage scheme. The condition of the animals was evaluated by clinical and haematological observations combined with quantification of biochemical infection markers: C-reactive protein, zinc and ascorbic acid. Within 48 h of treatment, the pigs in both treatment groups recovered clinically. No significant differences in the time-course of clinical observations or plasma concentrations of the biomarkers of infection were observed between the two treatments. In conclusion, the efficacy of these two dosage regimens of amoxycillin was not significantly different in treatment of acute Ap-infection in pigs.