多药耐药鲍氏不动杆菌耐药元件指标与样本聚类分析研究

Investigation of indicators and cluster analysis of multidrug-resistant Acinetobacter baumannii

目的调查多药耐药鲍氏不动杆菌β-内酰胺类与氨基糖苷类药物耐药的遗传学背景及可移动遗传元件携带状况。方法收集2008年1-12月某县级市医院住院患者痰标本中分离的多药耐药鲍氏不动杆菌共20株,采用聚合酶链反应(PCR)及序列分析的方法,分析获得性β-内酰胺类与氨基糖苷类耐药基因,以及可移动遗传元件,并对检测结果作指标与样本聚类分析。结果 20株鲍氏不动杆菌共检出3种获得性β-内酰胺类耐药基因,5种获得性氨基糖苷类耐药基因,5种可移动遗传元件的遗传标记;其余28种基因未检出;20株多药耐药鲍氏不动杆菌获得性β-内酰胺类与氨基糖苷类耐药基因以及可移动遗传元件检测结果指标聚类分析可见,ant(3″)-Ⅰ、aph(3′)-Ⅰ由tnpU、tnp513、intⅠ1介导,其他获得性耐药基因与可移动遗传元件也相关联;样本聚类分析示,3、12～15号株;4、11、16、19号株;5、8、10号株为3个克隆传播。结论在细菌耐药基因研究中,将检测结果分别作指标聚类分析和样本聚类分析,用于探讨可移动遗传元件介导的获得性耐药状况和菌株亲缘性简便有效。

OBJECTIVE To investigate genetic backgroud of resistance to beta-lactams and aminoglycosides,and the distribution of mobile genetic elements in multidrug-resistant Acinetobacter baumannii. METHODS From Jan 2008 to Dec 2008,20 strains of multidrug-resistant A.baumannii isolated from sputum were collected from a hospital of a county-level city.Then,acquired β-lactam-resistance genes,aminoglycoside-resistance genes,genetic markers of mobile genetic elements were analyzed by PCR.Furthermore,index and sample cluster analysis were performed. RESULTS In 20 strains of A.baumannii,3 kinds of acquired β-lactam-resistance genes,5 kinds of acquired aminoglycoside-resistance genes,5 kinds of mobile genetic elements were detected.However,the rest 28 kinds of genes were not detected out. CONCLUSIONS In this group of A.baumannii,index cluster analysis shows that ant（3″）-Ⅰ,aph（3′）-Ⅰare mediated by tnpU,tnp513,intⅠ1,and correlation existed between the rest kinds of acquired resistance genes and mobile genetic elements.