产质粒介导AmpC酶肺炎克雷伯菌的基因型分析与耐药性检测  

Resistance and Genotypes of Plasmid-mediated AmpC Beta-lactamases in Clinical Isolates of Klebsiella pneumoniae

作　　者：张运丽[1] 陈振华[1] 刘文恩[1] 

机构地区：[1]中南大学湘雅医院检验科,湖南长沙410008

出　　处：《中华医院感染学杂志》2010年第23期3641-3644,共4页Chinese Journal of Nosocomiology

摘　　要：目的研究湖南地区产质粒介导AmpC酶肺炎克雷伯菌的检出和耐药情况,确定其基因型并对其流行病学特征进行研究。方法采用头孢西丁纸片扩散法进行肺炎克雷伯菌AmpC酶表型初筛,提取质粒采用多重PCR技术检测质粒介导AmpC酶基因,设计引物进行结构基因的全长扩增和测序;并应用重复一致序列聚合酶链反应(ERIC-PCR)进行菌株同源性分析,用琼脂倍比稀释法检测产酶菌的药物敏感性。结果产质粒介导AmpC酶肺炎克雷伯菌的检出率为19.1%,均为DHA-1型质粒介导AmpC酶;ERIC-PCR结果显示,21株肺炎克雷伯菌有6种图谱类型,产质粒介导AmpC酶菌株呈多药耐药,但对亚胺培南的敏感率为100.0%。结论湖南地区产质粒介导AmpC酶肺炎克雷伯菌检测率高,其质粒介导的ampC耐药基因为DHA-1型基因,产酶菌株存在质粒传播和克隆传播,治疗相关感染以碳青酶烯类抗菌药物为首选药物。OBJECTIVE To study the resistance and genotypes of plasmid-mediated AmpC β-lactamases in Klebsiella pneumoniae in Hunan region.METHODS Using cefoxitin disk diffusion method to screen K.pneumoniae AmpC enzyme phenotype,and employing multiple PCR method to test ampC resistance genotypes in AmpC enzyme phenotype-positive K.pneumoniae strains.The PCR products were sequenced.The homology of AmpC-producing strains was detected by ERIC-PCR.The susceptibility was studied by agar dilution method.RESULTS The separation rate of producing plasmid-mediated AmpC enzyme of K.pneumoniae was 19.1%.Twenty-one clinical isolates presented positive at the 405bp bands by multiple PCR.21 strains carryied DHA type ampC resistance gene.There were 6 ERIC-PCR types in 21 isolates of DHA-producing K.pneumoniae.CONCLUSIONS The separation rate of producing plasmid-mediated AmpC enzyme of clinical K.pneumoniae strains in Changsha area is high,and its plasmid-mediated ampC resistance genes are all DHA genotypic.Carbapenems should be the first choice for the infection caused by plasmid-mediated AmpC enzyme of K.pneumoniae.

关 键 词：肺炎克雷伯菌 AMPC酶 质粒 DHA 重复一致序列聚合酶链反应 

分 类 号：R378.996[医药卫生—病原生物学]