质粒型AmpC酶基因在肠杆菌属细菌的检测与研究  

Study of plasmid-mediated AmpC β-lactamase among Enterobacter species

作　　者：侯喜琴[1] 任小英[1] 高燕渝[2] 马晓波[1] 李珣[1] 

机构地区：[1]厦门大学附属第一医院暨福建医科大学教学医院检验科,福建厦门361003 [2]四川大学华西医院感染性疾病中心,四川成都610041

出　　处：《中华医院感染学杂志》2016年第9期1924-1926,共3页Chinese Journal of Nosocomiology

基　　金：国家自然科学基金资助项目(81302529);福建省自然科学基金资助项目(2014D007)

摘　　要：目的对临床分离的26株头孢西丁高水平耐药肠杆菌属细菌进行检测,探讨其质粒型AmpCβ-内酰胺酶基因的分布。方法对2014年临床分离的头孢西丁MIC≥128μg/ml的26株肠杆菌属细菌进行检测,琼脂平皿二倍稀释法检测细菌的MIC,采用碱裂解变性法提纯质粒DNA,多重PCR法检测细菌上质粒型AmpCβ-内酰胺酶基因。结果对头孢西丁的MIC≥128μg/ml、对氨苄西林的MIC≥512μg/ml的菌株进行研究,头孢噻肟、头孢他啶、头孢吡肟和氨曲南的MIC90分别为512、64、32μg/ml和256μg/ml;26株肠杆菌属细菌中仅2株阴沟肠杆菌未检测到质粒型AmpC酶基因;分别有13、11株和4株肠杆菌属细菌检测到DHA、EBC和FOX条带;其中4株肠杆菌属细菌同时检测到两种基因,3株同时扩增到DHA和EBC条带。结论头孢吡肟可作为治疗该类细菌感染的首选药物;DHA、MIR-1、ACT-1型AmpCβ-内酰胺酶在肠杆菌属细菌中的分布相对较多。OBJECTIVE To investigate the distribution of plasmid-mediated AmpCβ-lactamase genes among 26 clinical isolates of high level cefoxitin-resistant Enterobacterspecies.METHODS A total of 26 clinical isolates of Enterobacter species with the MIC of cefoxitin no less than 128μg/ml were studied,then the minimum inhibitory concentration（MIC）of the strains was evaluated by agar dilution method,the plasmid DNA was purified by alkaline lysis method,and the plasmid-mediated AmpCβ-lactamase genes were detected by multiplex PCR.RESULTS The study was conducted among the strains with the MIC of cefoxitin no less than 128μg/ml and ampicillin no less than 512μg/ml;the MIC90 of cefotaxime was 512μg/ml,ceftazidime 64μg/ml,cefepime 32μg/ml,aztreonam256μg/ml.The plasmid-mediated AmpC was only tested negative in 2of 26 strains of Enterobacter species,and both were Enterobacter cloacae.The genes of DHA,EBC and FOX were respectively detected in 13 strains,11strains,and 4strains.The coexistence of two kinds of genes was found in 4isolates,and both DHA and EBC were amplified in 3strains.CONCLUSIONCefepime can be used as the first choice against infections caused by Enterobacter species.The DHA,MIR-1,and ACT-1are the major types of plasmid-mediated AmpCβ-lactamase in the Enterobacter species.

关 键 词：AMPC Β-内酰胺酶 质粒介导 肠杆菌属 

分 类 号：R378.2[医药卫生—病原生物学]