重症监护室耐碳青霉烯类铜绿假单胞菌相关耐药基因的研究

Carbapenem-resistance mechanism study of pseudomonas aeruginosa isolated from ICU patients

目的研究重症监护室耐碳青霉烯类铜绿假单胞菌的耐药机制。方法采用K-B法对44株耐碳青霉烯类铜绿假单胞菌进行药敏试验,采用PCR方法检测碳青霉烯酶金属酶(MBL)IMP、VIM、GIM、SPM和IMI耐药基因和外膜通道蛋白OprD2基因。结果对多黏菌素未出现耐药,对阿米卡星、哌拉西林/他唑巴坦、庆大霉素、头孢哌酮/舒巴坦、头孢他啶和头孢吡肟耐药率分别为13.6%、50.0%、31.8%、25.0%、40.9%和50.0%,对左旋氧氟沙星和头孢噻肟的耐药率都接近90%,亚胺培南、美洛培南、氨苄西林、头孢唑啉、头孢西丁的耐药率均为100%。检出OprD2基因缺失21株(47.7%),IMP阳性6株(13.6%),VIM阳性3株(6.8%),未检出GIM、SPM和IMI耐药基因。结论耐碳青霉烯类铜绿假单胞菌多重耐药情况严重。主要是由于外膜孔蛋白OprD2基因缺失和产金属酶IMP、VIM耐药基因引起。

Objective To investigate the carbapenem-resistant mechanisms of Pseudomonas aeruginosa of ICU. Methods Antibiotic susceptibility testing was performed by K-B method for 44 strains resistant to carbapenems Pseudomonas aeruginosa. All the strains were screened for the outer membrane prote in gene OprD2 and ca-rbapenem ase genes such as IMP, VIM, GIM, SPM and IMI with PCR. Results The resistance test showed that the resistance rates of the 44 strains Car- bapenem - resistant Pseudomonas aeruginosas to polymyxinB, amikacin, piperacillin/tazobactam, gentamicin, cefoperazone/ sulbactam, ceftazidime, cefepime were 0%, 13.6%, 50.0%, 31.8%, 25.0% ,40.9% and 50.0%, respectively. The resistance rate of levofloxacin, cephalosporin, cefotaximeis close to 90%, the resistance rate of imipenem, meropenem, ampieillin, cefazolin was 100%. The absent rate of OprD2 was 79.3%.The positive rates of blaIMP,blaVIM were 13.6%, 6.8%,respec- tively.GIM ,SPM and IMI genes were not found. Conclusion The situation of carbapenem resistance of pseudomonas aeruginosa is serious. The important mechanisms of carbapenem resistance of pseudomonas aeruginosa include：production of MBL（IMP and VIM）and deficiency of porin OprD2.