CAJ | 학술논문

目的探讨临床分离的产NDM-1肠杆菌科细菌的耐药机制及携带blaNDM-1质粒的特征和基因环境.方法连续收集2011年8月至2013年1月华南地区6家综合性医院临床非重复分离的碳青霉烯类耐药肠杆菌科细菌48株,同时选择大肠埃希菌J53作为接合试验受体菌.对所有菌株进行碳青霉烯水解酶表型试验(改良Hodge试验),用PCR法检测碳青霉烯类水解酶相关基因.通过脉冲场凝胶电泳(PFGE)观察携带blaNDM-1质粒的大小,通过对质粒进行酶切分析质粒的同源性及不相容群分型,并对临床上产NDM-1细菌感染患者的临床特征进行分析.结果 48株耐碳青霉烯类肠杆菌科细菌中有43株改良Hodge试验阳性.碳青霉烯酶耐药基因检测结果示,48株肠杆菌科细菌bla VIM、blaGIM和blaSPM均为阴性,19株细菌blaNDM-1基因为阳性,分别为3株大肠埃希菌、5株肺炎克雷伯菌、6株阴沟肠杆菌、3株弗劳地柠檬酸杆菌、1株产酸克雷伯菌和1株雷氏普罗威登斯菌.药敏试验结果显示,19株细菌均对亚胺培南、头孢噻肟、头孢他啶、头孢吡肟、氨曲南和哌拉西林/他唑巴坦耐药,对环丙沙星和左氧氟沙星的耐药率均为47.3％,但对阿米卡星的敏感率为68.4％.有13株产blaNDM-1细菌携带的blaNDM-1质粒均成功转移到大肠埃希菌J53中.接合子药敏试验结果显示,对亚胺培南、头孢他啶、头孢噻肟和哌拉西林/他唑巴坦仍耐药,但对阿米卡星、环丙沙星和左氧氟沙星均敏感.基因环境结果显示,接合子J-FR90(雷氏普罗威登斯菌)所有基因为阴性,其余12株细菌携blaNDM-1质粒blaSHV、aac-(6')-Ib基因均为阳性.PFGE显示,携blaNDM-1质粒大小基本一致,为50 kb左右.质粒之间有相似的酶切图谱,其相似度＞80％.质粒不相容群为IncX3型.菌株传代500代后,PCR检测显示所携带的blaNDM-1质粒均未丢失.19例产NDM-1细菌感染患者中6例死亡,13例存活.结论华南地区已出现产NDM-1的肠杆菌科细菌,主要通过IncX3型质粒在肠杆菌中传播.感染此类细菌的患者预后良好. 目的探討臨床分離的產NDM-1腸桿菌科細菌的耐藥機製及攜帶blaNDM-1質粒的特徵和基因環境.方法連續收集2011年8月至2013年1月華南地區6傢綜閤性醫院臨床非重複分離的碳青黴烯類耐藥腸桿菌科細菌48株,同時選擇大腸埃希菌J53作為接閤試驗受體菌.對所有菌株進行碳青黴烯水解酶錶型試驗(改良Hodge試驗),用PCR法檢測碳青黴烯類水解酶相關基因.通過脈遲場凝膠電泳(PFGE)觀察攜帶blaNDM-1質粒的大小,通過對質粒進行酶切分析質粒的同源性及不相容群分型,併對臨床上產NDM-1細菌感染患者的臨床特徵進行分析.結果 48株耐碳青黴烯類腸桿菌科細菌中有43株改良Hodge試驗暘性.碳青黴烯酶耐藥基因檢測結果示,48株腸桿菌科細菌bla VIM、blaGIM和blaSPM均為陰性,19株細菌blaNDM-1基因為暘性,分彆為3株大腸埃希菌、5株肺炎剋雷伯菌、6株陰溝腸桿菌、3株弗勞地檸檬痠桿菌、1株產痠剋雷伯菌和1株雷氏普囉威登斯菌.藥敏試驗結果顯示,19株細菌均對亞胺培南、頭孢噻肟、頭孢他啶、頭孢吡肟、氨麯南和哌拉西林/他唑巴坦耐藥,對環丙沙星和左氧氟沙星的耐藥率均為47.3％,但對阿米卡星的敏感率為68.4％.有13株產blaNDM-1細菌攜帶的blaNDM-1質粒均成功轉移到大腸埃希菌J53中.接閤子藥敏試驗結果顯示,對亞胺培南、頭孢他啶、頭孢噻肟和哌拉西林/他唑巴坦仍耐藥,但對阿米卡星、環丙沙星和左氧氟沙星均敏感.基因環境結果顯示,接閤子J-FR90(雷氏普囉威登斯菌)所有基因為陰性,其餘12株細菌攜blaNDM-1質粒blaSHV、aac-(6')-Ib基因均為暘性.PFGE顯示,攜blaNDM-1質粒大小基本一緻,為50 kb左右.質粒之間有相似的酶切圖譜,其相似度＞80％.質粒不相容群為IncX3型.菌株傳代500代後,PCR檢測顯示所攜帶的blaNDM-1質粒均未丟失.19例產NDM-1細菌感染患者中6例死亡,13例存活.結論華南地區已齣現產NDM-1的腸桿菌科細菌,主要通過IncX3型質粒在腸桿菌中傳播.感染此類細菌的患者預後良好.
목적 탐토림상분리적산NDM-1장간균과세균적내약궤제급휴대blaNDM-1질립적특정화기인배경.방법 련속수집2011년8월지2013년1월화남지구6가종합성의원림상비중복분리적탄청매희류내약장간균과세균48주,동시선택대장애희균J53작위접합시험수체균.대소유균주진행탄청매희수해매표형시험(개량Hodge시험),용PCR법검측탄청매희류수해매상관기인.통과맥충장응효전영(PFGE)관찰휴대blaNDM-1질립적대소,통과대질립진행매절분석질립적동원성급불상용군분형,병대림상상산NDM-1세균감염환자적림상특정진행분석.결과 48주내탄청매희류장간균과세균중유43주개량Hodge시험양성.탄청매희매내약기인검측결과시,48주장간균과세균bla VIM、blaGIM화blaSPM균위음성,19주세균blaNDM-1기인위양성,분별위3주대장애희균、5주폐염극뢰백균、6주음구장간균、3주불로지저몽산간균、1주산산극뢰백균화1주뢰씨보라위등사균.약민시험결과현시,19주세균균대아알배남、두포새우、두포타정、두포필우、안곡남화고랍서림/타서파탄내약,대배병사성화좌양불사성적내약솔균위47.3％,단대아미잡성적민감솔위68.4％.유13주산blaNDM-1세균휴대적blaNDM-1질립균성공전이도대장애희균J53중.접합자약민시험결과현시,대아알배남、두포타정、두포새우화고랍서림/타서파탄잉내약,단대아미잡성、배병사성화좌양불사성균민감.기인배경결과현시,접합자J-FR90(뢰씨보라위등사균)소유기인위음성,기여12주세균휴blaNDM-1질립blaSHV、aac-(6')-Ib기인균위양성.PFGE현시,휴blaNDM-1질립대소기본일치,위50 kb좌우.질립지간유상사적매절도보,기상사도＞80％.질립불상용군위IncX3형.균주전대500대후,PCR검측현시소휴대적blaNDM-1질립균미주실.19례산NDM-1세균감염환자중6례사망,13례존활.결론 화남지구이출현산NDM-1적장간균과세균,주요통과IncX3형질립재장간균중전파.감염차류세균적환자예후량호.
Objeetive To explore the mechanism of drug resistance of New Delhi metallo-β-lactamase-1 (NDM-1) producing Enterobacteriaceae,and to investigate the characteristics of blaNDM-1 carrying plasmid and its gene environment.Methods A total of 48 strains of carbapenem-resistant Enterobacteriaceae were successively collected from six general hospitals in south China during August 2011 and January 2013.Escherichia coli J53 was used for plasmid conjugation.Modified Hodge test was performed,and PCR method was used for the detection of carbarpenase-related genes.The relative molecular mass of the blaNDM-1 carrying plasmid was determined using pulsed field gel electrophoresis (PFGE)assay,and enzyme digestion was performed to investigate the homology and incompatibility group of the plasmid.Clinical feature of blaNDM-1 producing Enterobacteriaceae infection was also investigated.Results Among 48 strains of carbapenem-resistant Enterobacteriaceae,43 were positive in modified Hodge tests.blaVIM,blaGIM and blaSPM genes were negative in all strains,while blaNDM-1 was positive in 19 strains including 3 strains of Escherichia coli,5 strains of Klebsiella pneumoniae,6 strains of Enterobacter cloacae,3 strains of Citrobacterfreundii,1 strain of Klebsiella oxytoca and 1 strain of Providencia rettgeri.All the 19 strains were resistant to imipenem,cefotaxime,ceftazidime,cefepime,aztreonam and piperacillin/tazobactam,47.3％ strains were resistant to ciprofloxacin and levofloxacin,but 68.4％ strains were sensitive to amikacin.Conjugation experiment showed that,blaNDM-1 carrying plasmids in 13 strains were transmitted to the Escherichia coli J53.The conjugants were resistant to imipenem,ceftazidime,cefotaxime and piperacillin/tazobactam,but were sensitive to amikacin,ciprofloxacin and levofloxacin.All genes in conjugant J-FR90 (Providencia rettgeri) were negative,while the remaining 12 conjugants carried blaNDM-1,blaSHV and aac-(6')-Ib genes.PFGE showed that,the sizes of all blaNDM-1 carrying plasmids were about 50 kb,and more than 80％ of their macrorestriction maps were similar.The plasmid belonged to incompatibility group IncX3,and exhibited 100％ passage stability after 500 generations of propagation.Among 19 patients infected with NDM-1 producing Enterobacteriaceae,6 died and 13 survived.Conclusions NDM-1 producing Enterobacteriaceae is emerging in south China,and blaNDM-1 is transmitted to Enterobacteriaceae through IncX3.Patients infected with NDM-1 producing Enterobacteriaceae usually have good prognosis.