产超广谱β-内酰胺酶肺炎克雷伯菌耐药性及基因分型

Antimicrobial resistance and genotype of extended-spectrum β-lactamases-producing klebsiella pneumoniae

目的了解老年患者分离株产超广谱β-内酰胺酶(ESBLs)肺炎克雷伯菌的耐药性及基因型。方法药敏试验采用微量肉汤稀释法测定肺炎克雷伯菌对抗菌药物的耐药性,聚合酶链反应(PCR)法检测β-内酰胺酶耐药基因型并测序。结果产ESBLs肺炎克雷伯菌仅对第三代头孢菌素与β-内酰胺酶抑制剂合剂、碳青霉烯类抗菌药物较敏感;产ESBLs肺炎克雷伯菌中blaTEM、blaSHV、blaCTX-M-1群、blaCTX-M-9群、blaOXA-1群等5种β-内酰胺酶基因,阳性率分别为95.0%、30.0%、50.0%、5.0%、10.0%,同时携带2、3种以上耐药基因的菌株分别占40.0%和25.0%。结论产ESBLs肺炎克雷伯菌耐药性严重,基因型以blaTEM、blaCTX-M-1为主。

OBJECTIVE To investigate the antimicrobial resistance and genotypes of extended-spectrum β-lactamases-producing Klebsiella pneumoniae isolated from the old patients.METHODS Antimicrobial susceptibility tests were determined by microdilution test.Genotypes of β-lactamases were performed with PCR and verified by DNA sequence.RESULTS ESBLs-producing strains were only sensitive to the combination of the third generation cephalosporins with β-lactamases inhibitor and carbapenems.The positive rates of the detected genes of blaTEM,blaSHV,blaCTX-M-1,blaCTX-M-9 and blaOXA-1 were 95.0%,30.0%,50.0%,5.0% and 10.0% respectively.The strains carrying two and three kinds antimicrobial resistant genes accounted for 40.0% and 25.0%,respectively.CONCLUSION Antimicrobial resistance of ESBLs-producing K.pneumoniae is serious,the main genotypes are blaTEM and blaCTX-M-1.