多药耐药铜绿假单胞菌相关耐药基因研究

Multi-drug Resistant Genes of Pseudomonas aeruginosa Clinical Strains

目的明确临床分离的多药耐药铜绿假单胞菌(MRPA)耐药性及各种β-内酰胺酶编码基因、外膜通道蛋白oprD2基因、氨基糖苷类修饰酶相关基因、消毒剂与磺胺类耐药基因和质粒介导的氟喹诺酮类耐药基因存在状况。方法对2006年7-12月临床分离的32株铜绿假单胞菌,用K-B纸片扩散法和微量稀释法测定对庆大霉素等15种抗菌药物的敏感性,用聚合酶链反应(PCR)法检测28种铜绿假单胞菌相关耐药基因及外膜通道蛋白oprD2基因。结果32株MRPA对阿米卡星、头孢他啶、环丙沙星、头孢吡肟、头孢哌酮/舒巴坦、美罗培南、左氧氟沙星、哌拉西林/他唑巴坦、氨曲南、哌拉西林的耐药率分别为9.4%、25.0%、59.4%、68.7%、68.8%、78.1%、81.1%、81.3%、84.4%、94.4%,对其他抗菌药物耐药率均为100.0%;检出氨基糖苷类修饰酶基因aac(6′)-Ⅱ、aac(3)-Ⅱ、aac(6′)-Ⅰ、aph(3′)-Ⅵ、ant(3″)-Ⅰ和aac(3)-Ⅰ基因的阳性率分别为68.8%、62.5%、21.9%、9.4%、9.4%和6.3%,检出β-内酰胺酶编码基因blaFOX、blaIMP、blaVIM和blaDHA基因阳性率分别为37.5%、15.6%、6.3%和9.3%,22株(68.8%)外膜通道蛋白oprD2基因缺失,9株(28.1%)qacE-Δsul1基因扩增阳性,而其他基因均阴性。结论临床分离的多药耐药铜绿假单胞菌,氨基糖苷类修饰酶基因和β-内酰胺酶编码基因携带率很高,oprD2基因缺失率高。

OBJECTIVE To analyze the multi-drug resistant genes （genes encoding extended-spectrum β-lactamases, outer membrane protein gene oprD2, aminoglycoside-modifying enzyme genes, sulfonamides and disinfectantresistance gene and plasmid-mediated quinolone resistance gene） of Pseudomonas aeruginosa clinical strains. METHODS The drug-resistance to 15 antibiotics was detected by the disc agar diffusion （DAD） and microdilution broth method in 32 P. aeruginosa strains isolated from Jun to Dec 2006. Twenty-eight related drug-resistant genes and outer membrane protein gene oprD2 were examined by PCR method. RESULTS The resistance rate of 32 P. aeruginosa strains to amikacin, ceftazidime, ciprofloxacin, cefepime, cefoperazone/sulbactam, imipenem, meropenem, levofloxacin, piperacillin/tazobactam, aztreonam and piperacillin were 9.4 X, 25 %, 59.4 %, 68.7 %fro, 68.8%, 78.1%, 81.1%, 81.3%, 84.4% and 94.4%, respectively, and that to others antibiotics were 100%. The detective rate of aminoglycoside-modifying enzyme genes（aac（6%）-Ⅱ , aac（3）-Ⅱ , aac（6＇）-Ⅰ , aph（3r）-Ⅵ, ant（3″）-Ⅰ and aac（3）-Ⅰ ） were 68. 8%, 62.5%, 21.9%, 9. 4%, 9. 4% and 6. 3%,and the genes encoding extended-spectrum β-lactamases （blamx, blaiMp, blaviM and blaDaA） were 37. 5% 15. 6% 6. 3% and 9. 3%, respectively. Twenty-two （68.8%） of them were detected in oprD2 and 9 （28. 1%）, but positive in qacE△-sull gene. CONCLUSIONS The detective rate of aminoglycoside-modifying enzyme genes, extended-spectrum β- lactamases genes and the loss rate of outer membrane protein gene oprD2 are high in these 32 multi-drug resistant P. aeruginosa clinical strains.