泛耐药鲍氏不动杆菌看家基因和水平转移基因样本聚类分析

Phylogenetic Analysis of pandrug-resistant Acinetobacter baumannii based on housekeeping genes and genes acquired by horizontal transfer

目的了解20株泛耐药鲍氏不动杆菌的菌株亲缘性。方法完成该组泛耐药鲍氏不动杆菌2种与耐药相关的看家基因和54种水平转移获得与β-内酰胺类、氨基糖苷类、喹诺酮类耐药相关基因以及13种接合性质粒、转座子、插入序列、整合子等可移动遗传元件遗传标记检测,并对检测结果作样本聚类分析。结果 20株泛耐药鲍氏不动杆菌已经发生演化,并存在2个克隆传播:1-4-6号菌株和2-5-7-8-9-10-11-12-13-14-15-16-17-18-19号菌株。结论与耐药相关的看家基因和水平转移获得的耐药基因均为显性遗传,本研究耐药菌所观察的表型与之相对应,为追溯耐药菌传播途径提供了方便。

Objective To investigate phylogenecity of 20 strains of pandrug-resistant Acinetobacter baumannii （A. baumannii）. Method Resistance-related genes were analyzed by PCR, including 2 kinds of housekeeping genes and 54 kinds of resistance genes acquired by horizontal transfer to 3 kinds of antimicrobial agents ： β-1actams, aminoglycosides, quinolones, as well as 13 kinds of genetic markers of conjugal plasmids, transposons, insertion sequences, and integrons. Then phylogenetic analysis was performed. Result Twenty strains of pandrug-resistant A. baumannii showed evolution, and 2 clones existed： Strain 1-4-6 and Strain 2-5-7-8-9-10-11-12-13-14-15-16-17-18-19. Conclusion Resistance-related housekeeping genes and genes acquired by horizontal transfer were both dominant inheritance, which agreed with phenotypes of the group of pandrug-resistant A. baumannii. Thus, it is easy to trace the routes of transmission of drug-resistant strains.