质粒型AmpC酶DHA基因在耐药肺炎克雷伯菌中的流行研究  

Prevalence of plasmid-mediated AmpC beta-lactamase (DHA) in a group of drug-resistant Klebsiella pneumoniae

作　　者：鲁艳[1] 李从荣[2] 刘东华[1] 胡小平[1] 穆海霞[1] 

机构地区：[1]孝感市中心医院检验科,湖北孝感432000 [2]武汉大学人民医院检验科,湖北武汉430060

出　　处：《中华医院感染学杂志》2017年第16期3623-3626,共4页Chinese Journal of Nosocomiology

摘　　要：目的调查对常用抗菌药物耐药肺炎克雷伯菌(DRK)获得性耐药基因及相关可移动遗传元件的携带状况及菌株间的亲缘关系。方法 20株耐药肺炎克雷伯菌均分离自医院2015年1-12月住院患者痰标本,用K-B法测定抗菌药物的敏感性,采用聚合酶链反应(PCR)及序列分析的方法分析24种β-内酰胺类获得性耐药基因、11种氨基糖苷类获得性耐药基因、10种可移动遗传元件遗传标记,阳性耐药基因测序后直接作BLAST比对,耐药基因检测结果作样本聚类分析(UPGMA法)。结果 20株耐药肺炎克雷伯菌对β-内酰胺类、氨基糖苷类、喹诺酮类均耐药,但对碳青霉烯类均敏感;20株菌均检出β-内酰胺类获得性耐药基因,阳性率为100.0%,共检出6种β-内酰胺酶基因,blaDHA群基因检出率为最高90.0%;每株也均检出氨基糖苷类修饰酶基因,阳性率为100.0%,共检出4种氨基糖苷类获得性耐药基因,ant(3″)-Ⅰ群基因检出率为最高90.0%,但16SrRNA甲基化基因未检出;可移动遗传元件标记基因每株也均有检出,共检出7种可移动遗传元件标记基因,其中tnp513、IS26、IS903、ISEcp1、intⅠ1阳性率均为100.0%,trbC阳性率95.0%;样本聚类分析显示,该组菌株有明显的聚集性,分A与B二个群,B群又可分为B-1、B-2两个亚群,B-2亚群存在二个克隆传播,其中5-6号株均携带10种基因,4-7-8-9-13-14-15-16-17-18-19-20号株均携带9种基因。结论 20株耐药肺炎克雷伯菌同时携带了β-内酰胺类获得性耐药基因、氨基糖苷类修饰酶基因和可移动遗传元件标记基因,是对β-内酰胺类和氨基糖苷类产生耐药的重要原因,该组菌检出的2个克隆高度疑似医院感染,同一克隆菌株携带相同基因。OBJECTIVE To investigate the distribution of acquired resistant gene and genetic markers of mobile genetic elements in a group of drug-resistant Klebsiella pneumoniae （DRK）, and to investigate phylogenetics of this group of DRK.METHODS A total of 20 strains of DRK isolated from sputum were collected from the Xiaogan Central Hospital, Hubei Province from Jan.to Dec.2015.Drug sensitivity to antimicrobial agents were performed by K-B method, then 24 kinds of acquired beta-lactamase genes, 11 kinds of acquired genes to aminoglycosides, and 10 kinds of genetic markers of mobile genetic elements were analyzed by PCR.Positive resistant genes were verificated by DNA sequencing and BLAST algorithm.Finally, resistant genes were used as molecular markers to perform sample cluster analysis （UPGMA）.RESULTS Totally 20 strains of DRK were resistant to beta-lactams, aminoglycosides and quinolones, but susceptible to carbopenams.Acquired beta-lactamase genes, aminoglycoside modifying genes, and genetic markers of mobile genetic elements were positive in every strain, with the positive rates of 100%.Totally 6 kinds of beta-lactamase genes （positive rate of blaDHA was the highest： 90.0%）,4 kinds of aminoglycoside modifying genes （positive rate of ant（3″）-Ⅰ was the highest： 90.0%）, and 7 kinds of genetic markers of mobile genetic elements （positive rates of tnp513, IS26, IS903, ISEcp1, intⅠ1 were all 100.0%, and positive rates of trbC was 95.0%） were positive in this group, but 16SrRNA methylation gene was negative.Furthermore, sample cluster analysis showed that this group of strains appeared obvious aggregation, and were divided into cluster A and B, and cluster B were divided into subcluster B-1 and B-2,and 2 clones existed in subcluster B-2： strain No.5-6 all carried 10 kinds of genes, while strain No.4-7-8-9-13-14-15-16-17-18-19-20 all carried 9 kinds of gene.CONCLUSION Acquired beta-lactamase genes, aminoglycosides modifying enzyme genes, and genetic markers of mobile genetic elements in thi

关 键 词：肺炎克雷伯菌 耐药 Β-内酰胺类 氨基糖苷类修饰酶基因 可移动遗传元件 样本聚类分析 

分 类 号：R378.996[医药卫生—病原生物学]