多重耐药铜绿假单胞菌aac(6’)-Ⅱ型氨基糖苷类修饰酶基因研究

Aminoglycosides modifying enzyme aac(6')-II gene of multi-resistant drug pseudomonas aeruginosa

目的 进一步探讨铜绿假单胞菌 (Pseudomonasaeruginosa ,Pa)的耐药机制。 方法 从分离的 2 2株Pa中 ,经药敏试验、氨基糖苷类修饰酶耐药aac(6’) Ⅱ型基因的聚合酶链反应 (PCR)检测 ,筛选出 1株具有多重耐药的特征、氨基糖苷类修饰酶aac(6’) Ⅱ型阳性的菌株 ,对其耐药基因进行序列分析。 结果 Pa菌株扩增结果阳性 ,产物的长度为 178bp ,与标准产aac(6’) Ⅱ型菌株扩增片段长度大小一致 ;PCR产物经自动测序仪进行序列分析 ,共测得 132个核苷酸序列 ,经GenBank网上同源性比较 ,发现该序列与M2 96 95相比有 2个位点改变。 结论 国内临床上分离的Pa产aac(6’) Ⅱ型氨基糖苷类修饰酶基因 。

Objective To explore the drug resistance mechanism of Pseudomonas aeruginosa. Methods Twenty-two strains of clinically isolated Pseudomonas aeruginosa were collected from June 2003 to December 2003, antibiotic test and aac(6')-II type aminoglycosides modifying enzyme genes were tested by polymerase chain reaction(PCR). Sequence of the aac(6')-II gene was detected by ABI automated sequence and was compared with aac(6')-II gene that had been published in GenBank (Shaw KJ, Cramer CA, Rizzo M, et al. Antimicrob. Agents Chemother, 1989,33: 2052-2062). Results One hundred and thirty-two nucleotides were determined. Compare this sequence with the aac(6')-II gene (Accession No. M29695), there were two point mutations (GAC -GAT, GGC -GGT). Conclusion Multi-resistant drug pseudomonas aeruginosa may produce aminoglycosides modifying enzyme aac(6')-II gene, and there are aac(6')-II mutant strains in China.