摘要
目的研究临床分离碳青霉烯类抗菌药物耐药肠杆菌科细菌中新德里金属β-内酰胺酶(NDM)及其亚型的分布及流行特点。方法收集医院2014年1月-2015年1月各种临床标本中分离碳青霉烯类耐药肠杆菌科细菌563株,结合改良Hodge试验、EDTA协同及增效试验与PCR扩增检测blaNDM基因;通过肠杆菌基因间重复一致序列聚合酶链反应(ERIC-PCR)及多位点序列分型(MLST)分析菌株之间的同源性,采用药物敏感性试验、接合试验、质粒图谱分析、特异性聚合酶链反应(PCR)扩增和序列分析等技术研究细菌新德里金属β-内酰胺酶耐药的分子机制。结果共筛选出45株产NDM菌株,其中肺炎克雷伯菌38株,包括NDM-1型37株、NDM-5型1株,大肠埃希菌7株,均为NDM-7型;所有菌株呈现多药耐药现象,且每株菌均携带多种耐药基因,其中blaCTX-M、blaTEM、blaSHV、qnrB、qnrS、acc(6′)-Ib、rmtB、armA等为最常见共同携带耐药基因;MLST分型显示,产NDM-1肺炎克雷伯菌主要分布于ST11、ST76、ST495、ST37、ST700及ST395型中,产NDM-5肺炎克雷伯菌仅为ST14型;21株产NDM菌株接合试验阳性,其中包括13株NDM-1型、1株NDM-5型及7株NDM-7型,部分质粒之间有着相似图谱,blaNDM均定位于约46kb大小IncX3质粒上。结论医院已出现多种NDM亚型,主要通过IncX3型质粒在肠杆菌科细菌中传播,存在克隆传播现象;此外,NDM亚型的出现也表明NDM或正处于快速进化过程中而导致其广泛传播。
OBJECTIVE To explore the distribution and epidemiological characteristics of New Delhi metallo-β-lacta- mase （NDM） and its subtypes in clinical carbapenem-resistant Enterobacteriaceae isolates. METHODS A total of 563 strains of earbapenem-resistant Enterobacteriaceae were isolated from various clinical specimens from Jan 2014 to Jan 2015. The modified Hodge test, ethylenediaminetetraaeetic acid （EDTA） synergy and synergistic test, and PCR were employed to amplify and detect the blaNDM gene, the ERIC-PCR and multilocus sequence typing （MLST） were performed to analyze the molecular epidemiology of isolates. Antibiotic susceptibility testing, bonding test, plasmid profile analysis, specificity polymerase-chain-reaction （PCR）, and sequence analysis were carried out to confirm the molecular resistance mechanisms of the carbapenem-resistant Enterobacteriaceae isolates. RESULTS Totally 45 NDM-producing isolates were screened out, including 38 strains of Klebsiella pneumoniae （37 strains of NDM-1 type and 1 strain of NDM-5 type） and 7 strains of Escherichia coli （all were NDM-7 type）. All of the strains showed multidrug-resistant, and each strain carried with multiple drug resistance genes, among which blaCTX-M , blaTEM , blaSHV, qnrB , qnrS, acc （ 6′ ） -Ib , rmtB , and armA were the prevalent drug resistance genes. The MLST showed that the NDM-1-producing K. pneumoniae strains mainly belonged to the STll, ST76, ST495, ST37, STT00, and ST395 types, however, the NDM-5-producing K. pneumoniae strains belonged to ST14 type. Totally 21 NDM-producing isolates showed positive for the bonding test, including 13 strains of NDM- 1 type, 1 strain of NDM-5 type, and 7 strains of NDM-7 type; some of piasmids had the same gene map, and all of the blaNDM located on 46 kb of IncX3 plasmid. CONCLUSION Multiple NDM subtypes have emerged in hospitals and transmit among the Enterobacteriaceae strains via IncX3 plasmid, and there is clonal transmission; moreover, the emergence of the NDM subtypes indicates tha
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2017年第2期241-246,共6页
Chinese Journal of Nosocomiology
基金
国家自然科学基金资助项目(81560323)
江西省卫生厅中医药科研基金项目(2013A035)
江西省卫生计生委科技计划项目(20155140
20151031)
江西省科技厅青年基金资助项目(20151BAB215028)
