Background: Extended spectrum β-lactamases (ESBL) producing E. coli co-producing other β-lactamases and exhibiting co-resistance to different antibiotic classes continue to emerge as a threat to clinical field. This...Background: Extended spectrum β-lactamases (ESBL) producing E. coli co-producing other β-lactamases and exhibiting co-resistance to different antibiotic classes continue to emerge as a threat to clinical field. This study aimed to analyze the co-production of New Delhi metallo-β-lactamase-1 (blaNDM-1) in ESBL producing plasmid-bearing clinical isolates collected from two tertiary care centres in Kerala, South India, and to understand their genetic relatedness. Methods: Antibiotic resistance phenotypes of 44 clinical isolates were determined by disc-diffusion method. Plasmid-bearing isolates, detected by the alkaline-lysis method, which also tested positive for ESBL production, were screened for the presence of blaNDM-1 by polymerase chain reaction. Plasmid, random amplified polymorphic DNA profiles and blaNDM-1 sequence-based phylogenetic tree were analyzed to understand the genotypic similarities among the isolates. Results: Beta-lactam antibiotics, quinolones, cephalosporins, used in this study, and AZM were found to be ineffective against the isolates as significantly high number of isolates were resistant to these antibiotics (P < 0.01). Plasmid bearing isolates constituted 57% (n = 25), all of which were found to be ESBL producers. blaNDM-1 amplicons were noticed in four (16%) isolates and these DNA sequences showed homology between them and with similar sequences reported from other countries like Japan and Korea. Plasmid and RAPD profiles demonstrated that most of the isolates, including those harbouring blaNDM-1 shared genetic similarities as well as an apparent geographical distinctiveness. Conclusion: The predominance of ESBL production and the occurrence of blaNDM-1 in plasmid-bearing isolates observed in our study corroborate the worldwide drug-resistance scenario. This study thus warrants the need for constant surveillance in the face of sparse information available in Kerala State on the emerging drug resistance in clinical bacteria.展开更多
The emergence of multidrug resistance(MDR)in Proteus mirabilis clinical isolates is a growing public health concern and has serious implications for wildlife.What is the role of wildlife has been become one of the hot...The emergence of multidrug resistance(MDR)in Proteus mirabilis clinical isolates is a growing public health concern and has serious implications for wildlife.What is the role of wildlife has been become one of the hot issues in disseminating antimicrobial resistance.Here,54 P.mirabilis isolates from 12 different species were identified.Among them,25 isolates were determined to be MDR by profile of antimicrobial susceptibility;10 MDR P.mirabilis isolates were subjected to comparative genomic analysis by whole genome sequencing.Comprehensive analysis showed that chromosome of P.mirabilis isolates mainly carries multidrug-resistance complex elements harboring resistance to carbapenem genes blaOXA-1,blaNDM-1,and blaTEM-1.Class I integron is the insertion hotspot of IS26;it can be inserted into type I integron at different sites,thus forming a variety of multiple drug resistance decision sites.At the same time,Tn21,Tn7,and SXT/R391 mobile elements cause widespread spread of these drug resistance genes.In conclusion,P.mirabilis isolates from wildlife showed higher resistance to commonly used clinic drugs comparing to those from human.Therefore,wild animals carrying MDR clinical isolates should be paid attention to by the public health.展开更多
目的探讨1株碳青霉烯类耐药非脱羧勒克菌的耐药机制。方法采用全自动微生物分析仪、基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术及16S r RNA序列分析进行菌种鉴定;采用全自动微生物分析仪进行常规药物敏感性试验,用E-test条检...目的探讨1株碳青霉烯类耐药非脱羧勒克菌的耐药机制。方法采用全自动微生物分析仪、基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)技术及16S r RNA序列分析进行菌种鉴定;采用全自动微生物分析仪进行常规药物敏感性试验,用E-test条检测菌株对亚胺培南的最低抑菌浓度(MIC);改良碳青霉烯酶灭活试验(m CIM法)检测碳青霉烯酶表型;聚合酶链反应(PCR)及测序确定耐药基因型;采用接合试验、S1酶切脉冲场凝胶电泳(S1-PFGE)方法分析其携带质粒的特征。结果临床分离非脱羧勒克菌菌株对亚胺培南、除氨曲南外的其他β内酰胺类抗菌药物及氨基糖苷类耐药,对喹诺酮类和磺胺类药物敏感;接合试验使受体菌E.coli J53获得与非脱羧勒克菌相似的耐药谱。碳青霉烯酶表型试验阳性,PCR扩增及测序表明该菌株同时携带blaNDM-1、blaTEM和aac(6')-Ib,而接合子仅携带blaNDM-1;S1-PFGE示非脱羧勒克菌具有3个质粒。结论非脱羧勒克菌对碳青霉烯类药物耐药为携带blaNDM-1基因造成,该基因可能存在于100 kb左右的可接合传递的质粒上。展开更多
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
文摘Background: Extended spectrum β-lactamases (ESBL) producing E. coli co-producing other β-lactamases and exhibiting co-resistance to different antibiotic classes continue to emerge as a threat to clinical field. This study aimed to analyze the co-production of New Delhi metallo-β-lactamase-1 (blaNDM-1) in ESBL producing plasmid-bearing clinical isolates collected from two tertiary care centres in Kerala, South India, and to understand their genetic relatedness. Methods: Antibiotic resistance phenotypes of 44 clinical isolates were determined by disc-diffusion method. Plasmid-bearing isolates, detected by the alkaline-lysis method, which also tested positive for ESBL production, were screened for the presence of blaNDM-1 by polymerase chain reaction. Plasmid, random amplified polymorphic DNA profiles and blaNDM-1 sequence-based phylogenetic tree were analyzed to understand the genotypic similarities among the isolates. Results: Beta-lactam antibiotics, quinolones, cephalosporins, used in this study, and AZM were found to be ineffective against the isolates as significantly high number of isolates were resistant to these antibiotics (P < 0.01). Plasmid bearing isolates constituted 57% (n = 25), all of which were found to be ESBL producers. blaNDM-1 amplicons were noticed in four (16%) isolates and these DNA sequences showed homology between them and with similar sequences reported from other countries like Japan and Korea. Plasmid and RAPD profiles demonstrated that most of the isolates, including those harbouring blaNDM-1 shared genetic similarities as well as an apparent geographical distinctiveness. Conclusion: The predominance of ESBL production and the occurrence of blaNDM-1 in plasmid-bearing isolates observed in our study corroborate the worldwide drug-resistance scenario. This study thus warrants the need for constant surveillance in the face of sparse information available in Kerala State on the emerging drug resistance in clinical bacteria.
基金This study was supported by the Introduction of Leading Talents Program of Guangdong Academy of Sciences(No.2016GDASRC-0205)GDAS Special Project of Science and Technology Development(No.2018GDASCX-0107)Earmarked Fund for Hebei Dairy Cattle Innovation Team of Modern Agro-industry Technology Research System(No.HBCT2018120205).
文摘The emergence of multidrug resistance(MDR)in Proteus mirabilis clinical isolates is a growing public health concern and has serious implications for wildlife.What is the role of wildlife has been become one of the hot issues in disseminating antimicrobial resistance.Here,54 P.mirabilis isolates from 12 different species were identified.Among them,25 isolates were determined to be MDR by profile of antimicrobial susceptibility;10 MDR P.mirabilis isolates were subjected to comparative genomic analysis by whole genome sequencing.Comprehensive analysis showed that chromosome of P.mirabilis isolates mainly carries multidrug-resistance complex elements harboring resistance to carbapenem genes blaOXA-1,blaNDM-1,and blaTEM-1.Class I integron is the insertion hotspot of IS26;it can be inserted into type I integron at different sites,thus forming a variety of multiple drug resistance decision sites.At the same time,Tn21,Tn7,and SXT/R391 mobile elements cause widespread spread of these drug resistance genes.In conclusion,P.mirabilis isolates from wildlife showed higher resistance to commonly used clinic drugs comparing to those from human.Therefore,wild animals carrying MDR clinical isolates should be paid attention to by the public health.
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。
