深圳市人民医院产超广谱β-内酰胺酶和／或AmpC 酶奇异变形杆菌的流行及其分子特征  

Molecular cha ratce irs it cs of the extended-spectrum β-lactamase and/or AmpC enzyme-producing Proteus mirabilis strains prevelant in Shenzhen People′s Hospital

作　　者：吴伟元[1] 陆坚[2] 卢月梅[1] 吴劲松[1] 李文青[1] 程锦娥[1] 梁训宏[1] 吴文苑[1] 刘映霞[2] 

机构地区：[1]深圳市人民医院检验科,暨南大学第二临床医学院,深圳市病原微生物及细菌耐药监控重点实验室,518020 [2]深圳市第三人民医院,518112

出　　处：《中华微生物学和免疫学杂志》2014年第6期423-430,共8页Chinese Journal of Microbiology and Immunology

基　　金：广东省自然科学基金资助（5009113）

摘　　要：目的：调查深圳市人民医院产超广谱β-内酰胺酶（ ESBL ）和/或AmpC酶奇异变形杆菌的流行及其分子特征。方法使用ESBL表型初筛和确证试验以及AmpC酶纸片法检测产ESBL和/或AmpC酶奇异变形杆菌。 PCR扩增和DNA测序确定ESBL、AmpC酶基因型及其上游插入序列、质粒介导喹诺酮类耐药（ PMQR）基因型和染色体gyrA、gyrB和parC基因的喹诺酮类耐药决定区（ QRDRs）突变位点，以及整合酶基因和1类整合子基因盒。脉冲场凝胶电泳（ PFGE）分析菌株的同源性。结果2004-2010年我院临床共分离130株奇异变形杆菌，13株（10％）产 ESBL，3株（2．3％）产AmpC酶；产ESBL菌从0％～9．1％（2004-2009年）迅速上升至29．4％（2010年）。最常见ESBL基因型为 blaCTX-M-14（n＝7），其他 ESBL 基因型包括 blaCTX-M-65（n＝3）、blaCTX-M-55（n＝1）、blaCTX-M-24（n＝1）和blaPER-1（n＝1），系国内首次临床分离出携带blaPER-1奇异变形杆菌；2株产AmpC酶菌基因型为blaCMY-2，1株产AmpC酶菌基因型未知。91．7％（11/12）奇异变形杆菌的blaCTX-M上游和1株blaCMY-2上游均携带ISEcp1；1株blaPER-1上游携带ISPa12。66．7％（10/15）产ESBL和/或AmpC酶奇异变形杆菌携带qnrD（n＝5）和/或aac-Ib-cr（n＝8）。12株环丙沙星耐药产ESBL和/或AmpC酶菌在QRDRs中均携带GyrA上1个点突变（S83I）和ParC上1个点突变（S80I或S80R），其中6株还同时携带GyrB上1个点突变（E466D）。86．7％（13/15）产ESBL和/或AmpC酶菌携带1类整合子。15株产ESBL和/或AmpC酶奇异变形杆菌共获14种不同PFGE型别。结论产CTX-M型酶是我院奇异变形杆菌对超广谱头孢菌素耐药的主要机制，产ESBL和/或AmpC酶奇异变形杆菌大多携带qnrD和/或aac-Ib-cr基因。Objective To investigate the prevalence and molecular characteristics of the extended -spectrum β-lactamase （ ESBL） and AmpC enzyme-producing Proteus mirabilis （ P.mirabilis） strains isolated in Shenzhen People′s Hospital.Methods The production of ESBLs and AmpC enzymes by P.mirabilis isolates were detected by a screening and confirmatory test for ESBLs and AmpC disk test , respectively .The PCR assays followed by DNA sequencing of the products were employed to analyze the multiple genes including the ESBLs genes, AmpC genes, insertion sequences （ISs） upstream of the ESBLs or AmpC genes, plasmid -mediated quinolone resistance （ PMQR ） determinants , quinolone resistance-determining region （QRDR） genes , the integrase genes, and class1 integron cassette.The epidemiological analysis of the isolates was performed by pulsed field gel electrophoresis .Results There were 130 P.mirabilis clinical isolates collected from Shenzhen People′s Hospital in China during the year 2004 to 2010.Among them, 13 isolates （10%） produced ESBLs, that accounted for 0%-9.1%in the year 2004-2009 and up to 29.4%in 2010, and 3 isolates （2.3%） produced AmpC enzymes.The predominant genotype of ESBLs -producing isolateswas b al CTX-M-14（n=7）, followed by blaCTX-M-65（n=3）, blaCTX-M-55（n=1）, blaCTX-M-24（n=1） and blaPER-1 （n =1）.The clinical isolate of PER-1-producing P.mirabilis was reported for the first time in China.Twoisolates carried an AmpC β-lactamase gene of blaCMY-2 and one isolate carried an unidentified AmpC gene .ISEcp1 located upstream of blaCTX-M and blaCMY-2 were detected in 91.7% （11/12） of CTX-M-producing isolatesand one CMY-2-producing isolate, respectively.ISPa12 was present upstream of blaPER-1 in one studiedisolate.Approximately 66.7% （10/15） of ESBL and /or AmpC-producing isolates harbored PMQR genes including2 carrying qnrD, 5 carrying aac-Ib-cr and 3 carrying both qnrD and aac-Ib-cr.Twelve ESBL and /orAmpC-producers with high level of resistance to ciprofloxacin

关 键 词：奇异变形杆菌 超广谱Β-内酰胺酶 AMPC酶 脉冲场凝胶电泳 

分 类 号：R446.5[医药卫生—诊断学]