致病性小肠结肠耶氏菌DNA多态性及其毒力表达

摘要

目的探讨致病性小肠结肠耶氏菌(简称：耶氏菌)DNA特征及其表达。方法用聚合酶链反应(polymeraseChain Reaction；PCR)、DNA序列分析、随机扩增多态性DNA(Randomly Amplified Polymorphic DNA；RAPD)检测耶氏茵致病基因(adherent invasionlocus；ail)，并用自凝试验、刚果红试验检测其毒力表达。结果PCR和DNA序列分析证实致病性耶氏菌O：3、O：9、O：5，27血清型含有ail致病基因，而非致病型O：4，33、O：7，8血清型不含有ail基因。此外，O：22血清型也含有ail基因与文献报告ai1核苷酸序列同源性为88.3％。O：3、O：9、O：5，27致病血清型DNA指纹图谱相类似，O：22血清型有部分DNA片段与0：3血清型相似，而非致病O：4，33血清型DNA指纹图谱完全不同。毒力试验显示致病性耶氏茵全部阳性，3株O：22血清型均有少数菌落刚果试验阳性。结论致病性耶氏菌含有ail致病基因，DNA指纹图谱相似，但表现为多态性。O：22血清型含有ail基因，DNA指纹图谱部分与O：3血清型相似，少数菌落毒力试验呈阳性反应，该血清型可能存在潜在致病性。%Aim To study DNA characteristics and pathogenic expression of Yersinis enterocolitica. Method Polymerase chain reaction (PCR), analysis of DNA sequence, randomly amplified polymorphic DNA (RAPD) were used to investigate the pathogenic gene of adherent invasion locus (ail)and autoagglutination test and Congo red to observe the pathogenic expression of Yersinia enterocolitica. Results The Pathogenic Yersinia enteracolitica of serotyps O: 3、O: 9 and O:5, 27 were confirmed containing ail gene and the nonpathogenic of O:4, 33 and O: 7, 8 containing no one with PCR and analysis of DNA sequence. In addition,serotype O: 22 also contained ail gene which its nucleic acid sequence had homology of 88.3 % compared with the reported. There were similar DNA fingerprints among serotype O: 3 、 O: 9 and O: 5, 27 and was partly similar between O: 3 and O: 22, nonpathogenic serotype O: 4, 33 was entirely different from the pathogenic. All the pathogenic were positive in the utoagglutination test and Congo red. Conclusion The pathogenic Yersinia enterocolitica contained ail gene and had similar DNA fingerprints but expressing polymorphism, and also were positive in pathogenic expression. It may be possible that serotype O: 22 potentially express pathogenicity in some case with the fact that it contained ail gene and was partly similar in DNA fingerprints with O: 3, and a few colons being positive in pathogenic test.