新城疫病毒血凝素蛋白RNA适配体的筛选及活性研究

核酸适配体与单克隆抗体相比具有更高的分辨率,能识别配体间一个基团的细微差别,且所需的结合活性位点更小。本试验通过SELEX技术,体外经过12轮筛选获得了能够与F48E9株新城疫病毒特异性结合的3个RNA适配体,命名为FHN12-45-3、FHN12-36-6和FHN12-19-9。RNA适配体的二级机构预测结果显示,所筛选获得的RNA适配体空间结构以外环、内环、发夹环及突起结构为主。特异性试验结果显示,适配体FHN12-45-3经ELISA和Dot-blot试验证实能够区分不同株的新城疫病毒。生物学活性试验结果显示,适配体FHN12-45-3能够减少4个单位的F48E9株病毒血凝效价,初步表明适配体与F48E9株病毒可能的活性作用位点在血凝素蛋白上,在鸡胚成纤维细胞培养体系中适配体FHN12-45-3能够减少84.62%的F48E9株病毒蚀斑,荧光定量RT-PCR方法检测适配体FHN12-45-3能够减少培养体系中77.73%病毒载量,表明筛选的RNA适配体在细胞水平能够有效的抑制F48E9株新城疫病毒的复制。     

上海市禽源阿贡纳沙门氏菌耐药性及脉冲场凝胶电泳分型研究

To investigate the antimicrobial resistance and molecular types of S.agona strains isolated from poultry in Shanghai from 2010 to 2011,K-B method recommended by WHO was used to detect 14 strains of S.agona from poultry.Results were analyzed according to the breakpoints of CLSI,PFGE was used for molecular typing.14 strains were sensitive to 5 kinds of antibiotics.High resistant to sulfisoxazole and high moderate sensitivity to streptomycin.14 strains of S.agona were classified to 6 PFGE patterns.Some S.agona strains isolated from 2010 to 2011 were showed highly homology.Meanwhile,the relativity between antimicrobial susceptibility and PFGE patterns was remarkable.