聚合酶链反应检测鉴别鸡毒霉形体强毒株和弱毒疫苗株的研究

根据鸡毒霉形体 (MG)强毒株和弱毒疫苗株基因组结构特点 ,分别设计合成 2对引物XZ1、XZ2 和XZ4 5、XZ4 6 ,建立了可检测MG强、弱毒株的PCR方法。以引物XZ1、XZ2 对MG强毒株和弱毒株进行的PCR ,均可扩增出 732bp的特异性片段 ;而以另 1对引物XZ4 5、XZ4 6 对MG弱毒株进行PCR ,可扩增出 5 2 4bp的特异性片段 ,但对鸡毒霉形体标准强毒株和野毒株的PCR ,则扩增不出任何条带。特异性试验表明 ,这 2对引物对其他种类鸡毒霉形体及其他对照禽病病原核酸模板的扩增均为阴性。敏感性试验结果显示 ,2对引物PCR均能检出 10 0fg的MGDNA。研究结果表明 ,通过上述 2对引物的 2次PCR扩增 ,在数小时内即可鉴别出MG毒株是强毒株还是弱毒疫苗株

Detection and identification of Mycoplasma gallisepticum virulent and avirulent vaccine strains by polymerase chain reaction

The polymerase chain reaction (PCR) methods were developed and optimized to detect Mycoplasma gallisepticum (MG) virulent and avirulent strains. The 732 bp long specific DNA fragment of all MG virulent and avirulent strains was amplified by using the pair of primers XZ 1 , XZ 2 . The 524 bp long specific DNA fragment only for the MG avirulent strains was amplified by using the other pair of primers XZ 45 , XZ 46 , but not from other standard virulent and wild strains MG. There are also not any specific bands amplified from other kinds of mycoplasmata such as MS, MI, MM and other avian pathogenic viruses and bacteria by those two PCR. The sensitivity results showed that as little as 100 fg DNA of MG was detected by PCR with these two pairs of primers separately. Those MG virulent or avirulent vaccine strains were identified by two times PCR using the two pairs of primers during several hours.