碳青霉烯类耐药肺炎克雷伯菌分子流行病学及耐药机制

目的 研究碳青霉烯类耐药的肺炎克雷伯菌分子流行病学及对碳青霉烯类耐药机制。方法 KB法筛选对碳青霉烯类耐药的肺炎克雷伯菌临床分离株24株，同时采用微量肉汤稀释法测定这些细菌的最低抑菌浓度，改良Hodge实验检测碳青霉烯酶；PCR检测碳青霉烯酶基因(blaKPC、blaIMP、blaNDM、blaVIM、blaIMI、blaSPM、blaNDMOXA-23、blaNDMOXA-24、blaNDMOXA-48和blaNDMOXA-58)。结果 药敏试验显示碳青霉烯类耐药肺炎克雷伯菌具有多重耐药性。PCR扩增碳青霉烯酶基因，blaIMP阳性率为58.3%，经测序为IMP-4，其余均为阴性。结论 肺炎克雷伯菌临床分离株对碳青霉烯类抗生素的耐药机制主要与产IMP-4金属酶有关。

Molecular epidemiology and resistant mechanisms of carbapenem-resistant Klebsiella pneumoniae#br#

Objective To investigate molecular epidemiology and mechanisms of clinical isolates of Klebsiella pneumoniae resistant to carbapenems. Methods Antimicrobial susceptibility test was done on 24 strains of Klebsiella pneumoniae by the Kirby-Bauer method. The minimal inhibitive concentrations (MICs) of the antimicrobial agents were determined by the microdose broth dilution method. A modified Hodge test may assist in confirming the presence of carbapenemase. The genotype of KPC, IMP, NDM, VIM, IMI, SPM, OXA-23, OXA-24, OXA-48, and OXA-58 was detected by the polymerase chain reaction (PCR). Results Clinical isolates of carbapenem-resistant Klebsiella pneumoniae were multi-drug resistant. Positive rate of blaIMP in Klebsiella pneumoniae was 58.3% (It was later detected as IMP-4). But no KPC, NDM, VIM, IMI, SPM, OXA-23, OXA-24, OXA-48, and OXA-58 genes were detected. Conclusion Production of metallo-β-lactamase IMP-4 in Klebsiella pneumoniae was the main mechanisms of carbapenem