目的了解临床分离碳青霉烯类不敏感革兰阴性杆菌中bla_(NDM-1)基因的分布,探讨NDM-1阳性菌株的分子流行病学特征。方法收集长沙地区2011年1月—2012年8月临床分离非重复碳青霉烯类不敏感革兰阴性杆菌,聚合酶链反应(PCR)技术筛查bla_(NDM...目的了解临床分离碳青霉烯类不敏感革兰阴性杆菌中bla_(NDM-1)基因的分布,探讨NDM-1阳性菌株的分子流行病学特征。方法收集长沙地区2011年1月—2012年8月临床分离非重复碳青霉烯类不敏感革兰阴性杆菌,聚合酶链反应(PCR)技术筛查bla_(NDM-1)基因,扩增产物测序和BLAST软件分析。对bla_(NDM-1)基因阳性菌株,采用E试验法检测其药物敏感性、PCR法检测β内酰胺酶基因(包括bla_(DHA)、bla_(VIM)、bla_(IMP)、bla_(GIM)、bla_(CTX-M)、bla_(KPC)、bla_(TEM)和bla_(SHV)等)和16S r RNA甲基化酶基因、脉冲场凝胶电泳(PFGE)及多位点序列分型(MLST)技术进行分子生物学分型。结果共收集到687株碳青霉烯类不敏感的革兰阴性杆菌,其中3株被证实为bla_(NDM-1)基因阳性菌株,包括2株肺炎克雷伯菌(菌株编号CS11495和CS610)和1株阴沟肠杆菌(菌株编号CS30754)。该3株菌均来源于湘雅医院。在测试的12种抗菌药物中,除对阿米卡星和多黏菌素B敏感外,对其余抗菌药物几乎全耐药。菌株CS11495同时检出bla_(SHV-12)、bla_(TEM-1)、bla_(CTX-M-15)和bla_(IMP-4),菌株CS610携带bla_(DHA)、bla_(SHV-12)和bla_(TEM-1),菌株CS30754中bla_(SHV-12)和bla_(TEM-1)基因阳性。其余基因均为阴性。2株肺炎克雷伯菌PFGE分型可分为A、B两型。MLST显示,菌株CS11495、CS610和CS30754分别属于ST629、ST490及ST214,其中ST490为国内首次报道。结论 bla_(NDM-1)阳性菌株具有广泛的耐药谱,与其同时携带多种耐药基因有关。尽管本地区不存在克隆传播,但分布于同一医院的不同科室,应预防其播散。展开更多
Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli...Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli) and 28 Klebsiella pneumoniae(K.pneumoniae) that was resistant to a third generation cephalosporin and obtained during 2007-2008 was selected for detailed screening for bla_(CTX-M),bla_(TEM),and bla_(SHV) by monoplex PCRs.The isolates demonstrating the presence of bla_(CTX-M) alleles were characterized for the specific CTX-M-genogroup by using a multiplex PCR.Results:Resistance to cefoperazone,ceftazidime,ceftriaxone,cefotaxime, cefoxitin and piperacillin was 100%each in K.pneumoniae isolates,whereas these resistancerates for E.coli isolates were 93.1%,83.8%,91.9%,93.6%,97.3%and 97.1%,respectively. Concomitant resistance to aminoglycosides,quinolones and aztreonam was also noticed.Presence of any of the bla genes(bla_(CTX-M),bla_(TEM),and bla_(SHV)) was noticed in a total of 28(38.4%) isolates of the 73 isolates studied.Many isolates demonstrated occurrence of these genes in various combinations.bla_(CTX-M),bla_(TEM),and bla_(SHV) were noticed in 28.8%,10.9%and 13.7%isolates, respectively.Multiplex PCR in bla_(CTX-M) harboring isolates demonstrated the presence of CTX-MGenogroup -1 and sequencing for the specific CTX-M-type revealed presence of CTX-M-15 type. RAPD typing showed wide diversity in isolates.Conclusions:This is amongst the premier report describing the simultaneous occurrence of blo_(TEM),bla_(SHV),and bla_(ampC) in Indian Enterobacteriaceae and that wider dissemination of these genes,as demonstrated by diversity of isolates,raises concern and emphasizes a need for extensive search for the presence of these gene pools in Indian subcontinent.展开更多
文摘目的了解临床分离碳青霉烯类不敏感革兰阴性杆菌中bla_(NDM-1)基因的分布,探讨NDM-1阳性菌株的分子流行病学特征。方法收集长沙地区2011年1月—2012年8月临床分离非重复碳青霉烯类不敏感革兰阴性杆菌,聚合酶链反应(PCR)技术筛查bla_(NDM-1)基因,扩增产物测序和BLAST软件分析。对bla_(NDM-1)基因阳性菌株,采用E试验法检测其药物敏感性、PCR法检测β内酰胺酶基因(包括bla_(DHA)、bla_(VIM)、bla_(IMP)、bla_(GIM)、bla_(CTX-M)、bla_(KPC)、bla_(TEM)和bla_(SHV)等)和16S r RNA甲基化酶基因、脉冲场凝胶电泳(PFGE)及多位点序列分型(MLST)技术进行分子生物学分型。结果共收集到687株碳青霉烯类不敏感的革兰阴性杆菌,其中3株被证实为bla_(NDM-1)基因阳性菌株,包括2株肺炎克雷伯菌(菌株编号CS11495和CS610)和1株阴沟肠杆菌(菌株编号CS30754)。该3株菌均来源于湘雅医院。在测试的12种抗菌药物中,除对阿米卡星和多黏菌素B敏感外,对其余抗菌药物几乎全耐药。菌株CS11495同时检出bla_(SHV-12)、bla_(TEM-1)、bla_(CTX-M-15)和bla_(IMP-4),菌株CS610携带bla_(DHA)、bla_(SHV-12)和bla_(TEM-1),菌株CS30754中bla_(SHV-12)和bla_(TEM-1)基因阳性。其余基因均为阴性。2株肺炎克雷伯菌PFGE分型可分为A、B两型。MLST显示,菌株CS11495、CS610和CS30754分别属于ST629、ST490及ST214,其中ST490为国内首次报道。结论 bla_(NDM-1)阳性菌株具有广泛的耐药谱,与其同时携带多种耐药基因有关。尽管本地区不存在克隆传播,但分布于同一医院的不同科室,应预防其播散。
基金Department of Science & Technology,Ministry of Science & Technology,Government of India,for the award of Young Scientist Project(SR/FT/ L-111/2006)
文摘Objective:To delineate the frequency of occurrence of bla_(CTX-M),bla_(TEM),and bla_(SHV) in Enterobacteriaceae from North-Indian tertiary hospital.Methods:A random collection of a subset of 45 Escherichia coli(E.coli) and 28 Klebsiella pneumoniae(K.pneumoniae) that was resistant to a third generation cephalosporin and obtained during 2007-2008 was selected for detailed screening for bla_(CTX-M),bla_(TEM),and bla_(SHV) by monoplex PCRs.The isolates demonstrating the presence of bla_(CTX-M) alleles were characterized for the specific CTX-M-genogroup by using a multiplex PCR.Results:Resistance to cefoperazone,ceftazidime,ceftriaxone,cefotaxime, cefoxitin and piperacillin was 100%each in K.pneumoniae isolates,whereas these resistancerates for E.coli isolates were 93.1%,83.8%,91.9%,93.6%,97.3%and 97.1%,respectively. Concomitant resistance to aminoglycosides,quinolones and aztreonam was also noticed.Presence of any of the bla genes(bla_(CTX-M),bla_(TEM),and bla_(SHV)) was noticed in a total of 28(38.4%) isolates of the 73 isolates studied.Many isolates demonstrated occurrence of these genes in various combinations.bla_(CTX-M),bla_(TEM),and bla_(SHV) were noticed in 28.8%,10.9%and 13.7%isolates, respectively.Multiplex PCR in bla_(CTX-M) harboring isolates demonstrated the presence of CTX-MGenogroup -1 and sequencing for the specific CTX-M-type revealed presence of CTX-M-15 type. RAPD typing showed wide diversity in isolates.Conclusions:This is amongst the premier report describing the simultaneous occurrence of blo_(TEM),bla_(SHV),and bla_(ampC) in Indian Enterobacteriaceae and that wider dissemination of these genes,as demonstrated by diversity of isolates,raises concern and emphasizes a need for extensive search for the presence of these gene pools in Indian subcontinent.
