铜绿假单胞菌质粒介导的喹诺酮耐药机制研究

Identification of multidrug resistance genes in quinolone-resistance Pseudomonas aeruginosa with plasmid conjugation method

目的探讨铜绿假单胞菌对质粒介导喹诺酮类耐药(PMQR)机制,为控制其耐药性传播提供依据。方法筛选住院患者对环丙沙星耐药的69株铜绿假单胞菌,PCR筛选质粒介导的喹诺酮类耐药基因[qnr,aac(6')-Ib-cr],阳性产物进行DNA测序,接合转移试验验证PMQR基因。结果 69株受试株中,12株aac(6')-Ib-cr基因阳性,经DNA测序、BLAST比对,3株携带aac(6')-Ib-cr基因(含有Trp-102→Arg和Asp-179→Tyr突变),另有3株为aac(6')-Ib野生型;质粒接合转移试验结果阴性;未检出qnr基因。结论铜绿假单胞茵PMQR基因以aac(6')-Ib-cr基因为主,未检出qnr基因,aac(6')-Ib-cr基因介导低水平耐药。

Objective To identify multidrug resistance genes in quinolones resistance-Pseudomonas aeruginosa （PMQR）. Methods Sixty nine clinical isolated of ciprofloxacin-resistant Pseudomonas aeruginosa were collected. Quinolone resistance genes [qnr, aac （6 ＇） - Ib-cr] were screened with PCR plasmid-mediated method, positive products were DNA sequenced, and PMQR genes were verified with plasmid conjugation method. Results Among 69 strains tested, 12 were aac （6 ＇） - Ib-cr gene positive shown by DNA sequencing, BLAST comparison, including 3 contained mutated aac （6＇） - Ib-cr gene （Trp-102 →Arg and Asp-179 →Tyr）, and another 3 carried wild type aac （6 ＇） - Ib; while plasmid conjugation test was negative and qnr gene was not detected. Conclusion The clinical isolates of Pseudomonas aeruginosa are aac （6 ＇） - Ib-cr -based low-level resistance PMQR, and qnr gene is not detected.