产KPC铜绿假单胞菌的耐药性研究

A study on drug resistance of KPC carbapenemase-producing Pseudomonas aeruginosa

目的探讨产肺炎克雷伯菌碳青霉烯酶(KPC)铜绿假单胞菌的耐药性。方法铜绿假单胞菌菌株来自2例痰液标本。采用VITEK 2COMPACT全自动微生物鉴定/药敏分析仪进行细菌菌株的鉴定,应用聚合酶链反应(PCR)及基因测序法鉴定KPC酶基因型,采用肉汤稀释法进行抗菌药的最低抑菌浓度(MIC)测定。结果 2例菌株均对β-内酰胺类抗菌药、左氧氟沙星耐药,对环丙沙星中介,对庆大霉素、奈替米星、妥布霉素、黏菌素及多黏菌素B敏感;其中1株还对替加环素敏感。2例菌株所产碳青霉烯酶不是金属β-内酰胺酶,其亚型为KPC-2。接合实验未能证明bla KPC基因能接合转移到大肠埃希菌J53中。结论产KPC铜绿假单胞菌的出现给临床抗感染治疗带来严峻挑战。

Objective To investigate the drug-resistance of Pseudomonas aeruginosa which producing K lebsiella pneumoniae carbapenemases（KPC） .Methods Pseudomonas aeruginosa strains were derived from two sputum samples .VITEK 2 COMPACT Automated Microbial Identification/Susceptibility Analyzer was employed to identify the bacterial strains .Polymerase chain reaction （PCR） and gene sequencing were adopted to identify the genotypes of KPC enzyme ,Broth dilution method was used to measure the minimal inhibitory concentration（MIC） of antimicrobial agents .Results Both Pseudomonas aeruginosa strains were resistant to β-lactam antibiotic and levofloxacin ,and were intermediary to ciprofloxacin ,and sensitive to gentamicin ,netilmicin ,tobramycin ,colistin and multi-polymyxin B .One of them was sensitive to tigecycline .Carbapenemase produced by the two stains was not metal β-lacta-mase ,with the subtype of KPC-2 .Mating experiments failed to prove the bla K PC gene could be transferred to E .coli J53 .Conclu-sion Appearance of KPC-producing Pseudomonas aeruginosa poses serious challenges to clinical anti-infective therapy .