产超广谱β-内酰胺酶和质粒介导的AmpC酶肺炎克雷伯菌耐药性及基因型研究

目的了解我院临床分离的肺炎克雷伯菌耐药性及超广谱β-内酰胺酶和质粒介导的AmpC酶基因型.方法采用Microscan微生物鉴定仪、微量肉汤稀释法,测定临床分离的肺炎克雷伯菌对21种抗菌药物的敏感性;采用聚合酶链反应(PCR)及测序技术分析超广谱β-内酰胺酶和质粒介导的AmpC酶基因型.结果肺炎克雷伯菌对亚胺培南全部敏感,对环丙沙星、哌拉西林/他唑巴坦、头孢他啶、头孢西丁、头孢哌酮/舒巴坦、阿莫西林/舒巴坦、阿米卡星、头孢噻肟和头孢哌酮的耐药率分别为36.6%、38.3%、56.7%、63.4%、81.7%、86.7%、96.6%、98.3%和98.3%,对其他药物的耐药率为100%;60株肺炎克雷伯菌全部扩增出TEM基因,有25株细菌检出CTX-M-Ⅰ群基因,有54株细菌扩增出DHA基因,而PER和MIR(ACT-1)全部为阴性;且有21株肺炎克雷伯菌同时携带CTX-M-Ⅰ群、DHA和TEM基因.结论我院临床分离的肺炎克雷伯菌为多重耐药菌,同时存在CTX-M-3型超广谱β-内酰胺酶和DHA-1型质粒介导的AmpC酶,尚未发现PER型超广谱β-内酰胺酶和MIR型质粒介导的AmpC酶.

Antibiotic Resistance and Genotyping of Plasmid- mediated Extended Spectrum Beta Lactamases and AmpC Beta Lactamases in Klebsiella pneumoniae

OBJECTIVE To investigate the resistance and genotyping of plasmid-mediated extended spectrum beta lactamases (ESBLs) and AmpC beta lactamases (pAmpC) in Klebsiella pneumoniae (Kpn) isolated from Huanhu Hospital of Tianjin. METHODS A total of 60 Kpn strains were tested to 21 drugs in vitro susceptibility by Microscan MIC method. The PCR and DNA sequencing methods were used to determine the genotypes of ESBLs and pAmpC. RESULTS The 60 strains were multi-resistant, from them three beta-lactamase genes were found. There were TEM type broad-spectrum beta lactamases gene in 60 strains, CTX-M type ESBLs gene in 25 strains and DHA type pAmpC beta lactamases gene in 54 strains. CTX-M type ESBLs and DHA type pAmpC beta lactamases genes simultaneously occurred in 21 strains. CONCLUSIONS The resistance of Kpn isolated from Huanhu Hospital of Tianjin is a serious issue and at least three kinds of beta lactamases genes are existing.