血流感染肺炎克雷伯菌对碳青霉烯类抗菌药物耐药机制研究

目的了解临床血流感染肺炎克雷伯菌对碳青霉烯类抗菌药物的耐药机制,为其治疗提供实验依据。方法收集浙江省人民医院2016年1月-12月门诊及住院患者血流感染肺炎克雷伯菌72株,应用法国梅里埃VITEK 2 Compact检测肺炎克雷伯菌药物敏感性;应用PCR法检测相关碳青霉烯酶耐药基因(blaKPC、blaNDM、blaVIM、blaIMI、blaIMP和blaOXA-48),应用MLST方法检测菌株克隆型别。结果 2016年1月-12月门诊及住院患者血流感染肺炎克雷伯菌72株,其中碳青霉烯敏感肺炎克雷伯菌(CSKP) 48株,占66.7%,碳青霉烯耐药肺炎克雷伯菌(CRKP) 24株,占33.3%;肺炎克雷伯菌对常用抗菌药物敏感性均较低,特别是β-内酰胺类抗菌药物。替加环素体外显示出极高敏感性,仅4.2%菌株耐药;24株菌株全部检出blaKPC-2基因,其他耐药基因未检出。结论本院血流感染肺炎克雷伯菌对碳青霉烯类抗菌药物的耐药机制主要是产KPC-2酶。碳青霉烯耐药肺炎克雷伯菌在本院呈克隆播散趋势,应引起临床高度重视。

Study on the mechanism of carbapenem-resistant Klebsiella pneumoniae in bloodstream infection

Objective To investigate the resistance mechanism of carbapenem-resistant Klebsiella pneumoniae(CRKP)isolated in bloodstream infection,and to provide experimental basis for its treatment.Methods A total of 72 Klebsiella pneumoniae strains isolated in outpatient and inpatient patients in Zhejiang Provincial People’s Hospital from January to December in 2016 were collected,and MICs were determined by VITEK 2 Compact method.PCR was performed to detect carbapenem resistance genes(blaKPC,blaNDM,blaVIM,blaIMI,blaIMP and blaOXA-48),and the PCR products were further sequenced.MLST was determined to analyze the sequence types.Results From January to December in 2016,there were 72 strains of Klebsiella pneumoniae were collected,including 48 carbapenem susceptible Klebsiella pneumoniae(CSKP) strains(66.7%),and 24 CRKP strains(33.3%).Klebsiella pneumoniae strains were less sensitive to commonly used antimicrobial agents,especiallyβ-lactams antimicrobial agents.In addition,tigecycline showed extremely high sensitivity and only 4.2% of the strains were resistant.The blaKPC-2 gene was detected in all 24 strains,and other resistant genes were not detected.Conclusion The resistance mechanism of the clinical carbapenem-resistant Klebsiella pneumoniae is mainly related to the production of KPC-2 enzyme.In addition,these strains were clone spreading in our hospital.The risk of dissemination should be paid attention to in the clinical.