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
目的了解汕头市水产品非O1/O139群霍乱弧菌的耐药基因、毒力基因、序列位点信息,分析不同菌株间遗传关系。方法收集分离自水产品的霍乱弧菌41株,对菌株进行全基因组序列测定,利用生物信息学工具预测菌株的耐药基因和毒力基因情况,结合...目的了解汕头市水产品非O1/O139群霍乱弧菌的耐药基因、毒力基因、序列位点信息,分析不同菌株间遗传关系。方法收集分离自水产品的霍乱弧菌41株,对菌株进行全基因组序列测定,利用生物信息学工具预测菌株的耐药基因和毒力基因情况,结合美国国家生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库,进行多位点序列分型分析(multilocus sequence typing,MLST)和核心基因组单核苷酸多态性分析(core gene single nucleotide polymorphism,cgSNP)。结果41株霍乱弧菌共检测到34个抗生素耐药基因,携带率最高的是dfrA31(46.3%),部分菌株携带能水解所有β-内酰胺酶的blaNDM-1基因。毒力基因携带率最高的是rtxA(100.0%)和hlyA(97.6%),所有病原菌株均不携带ctxA和ctxB,致病岛VPI-1/VPI-2携带率分别为31.7%/70.7%,T6SS和第7次大流行特征基因岛VSP-1/VSP-2的检出率都是4.9%。MLST和cgSNP分析显示,共有30种不同的序列型(sequencetypes,STs),其中20种为新分配的STs。结论汕头市水产品中非O1/O139群霍乱弧菌携带多种毒力基因和耐药基因,其中霍乱弧菌携带blaNDM-1基因为国内首次报道。不同物种来源的菌株遗传多样性高,发现大量新STs型。展开更多
The widespread occurrence of carbapenem-resistant organisms has garnered significant public attention.Arthro-pods,including flies,are important vectors of multidrug-resistant bacteria.In this study,we reported the sim...The widespread occurrence of carbapenem-resistant organisms has garnered significant public attention.Arthro-pods,including flies,are important vectors of multidrug-resistant bacteria.In this study,we reported the simultane-ous carriage of four carbapenem-resistant isolates from different species,namely,Escherichia coli(E.coli),Providencia manganoxydans(P.manganoxydan),Myroides odoratimimus(M.odoratimimus)and Proteus mirabilis(P.mirabilis),from a single fly in China.These isolates were characterized through antimicrobial susceptibility testing,conjuga-tion assays,whole-genome sequencing,and bioinformatics analysis.M.odoratimimus showed intrinsic resistance to carbapenems.The mechanisms of carbapenem resistance in E.coli,P.manganoxydans,and P.mirabilis were due to the production of NDM-5,NDM-1 and NDM-1,respectively.Genetic context of the bla_(NDM) genes in these three isolates varied.The bla_(NDM-5) gene in E.coli was located on an IncHI2/HI2A multidrug-resistant plasmid,which was con-jugatively transferable.The bla_(NDM-1) gene in P.mirabilis resided on the pPM14-NDM_123k-like nonconjugative plasmid.The bla_(NDM-1) gene in P.manganoxydans was found in a nonconjugatively transferable,multidrug-resistant region.The results of this study enhance our understanding of the dissemination of carbapenem-resistant organisms and sug-gest the need for a more comprehensive approach to antibiotic resistance research encompassing humans,animals,and the environment.展开更多
Antimicrobial resistance(AMR)has become a critical global public health challenge in the 21st century.Since the initial isolation of a blaNDM-1-carrying and carbapenem-resistant Klebsiella pneumoniae from an Indian ho...Antimicrobial resistance(AMR)has become a critical global public health challenge in the 21st century.Since the initial isolation of a blaNDM-1-carrying and carbapenem-resistant Klebsiella pneumoniae from an Indian hospital in 2009[1],the escalating prevalence of New Delhi metallo-β-lactamase(NDM)-encoding genes(blaNDM)has transformed carbapenem resistance into a worldwide phenomenon,transcending national and regional boundaries[2].Up to 90 distinct NDM variants have been reported globally according to the NCBI GenBank Pathogens database.Plasmidmediated horizontal gene transfer(HGT),which occurs both within and across bacterial species,has significantly accelerated the global dissemination of blaNDM-related genes and the associated resistance[3].Carbapenem-resistant pathogens were responsible for 200,000 deaths globally in 2019[4].Although NDM-1 has been relatively well characterized[5],the epidemiological profiles of other NDM variants require continued surveillance and indepth investigation.The novel NDM-9 variant(GenBank accession no.KC999080)was first identified in 2013 from a clinically significant isolate of Klebsiella pneumoniae ST107 strain PPH1303 with a high level of resistance to carbapenems recovered from the urine culture of a pediatric patient in Beijing,China,who had acute lymphocytic leukemia and had undergone allogeneic stem cell transplantation[6].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.
文摘目的了解汕头市水产品非O1/O139群霍乱弧菌的耐药基因、毒力基因、序列位点信息,分析不同菌株间遗传关系。方法收集分离自水产品的霍乱弧菌41株,对菌株进行全基因组序列测定,利用生物信息学工具预测菌株的耐药基因和毒力基因情况,结合美国国家生物技术信息中心(National Center for Biotechnology Information,NCBI)数据库,进行多位点序列分型分析(multilocus sequence typing,MLST)和核心基因组单核苷酸多态性分析(core gene single nucleotide polymorphism,cgSNP)。结果41株霍乱弧菌共检测到34个抗生素耐药基因,携带率最高的是dfrA31(46.3%),部分菌株携带能水解所有β-内酰胺酶的blaNDM-1基因。毒力基因携带率最高的是rtxA(100.0%)和hlyA(97.6%),所有病原菌株均不携带ctxA和ctxB,致病岛VPI-1/VPI-2携带率分别为31.7%/70.7%,T6SS和第7次大流行特征基因岛VSP-1/VSP-2的检出率都是4.9%。MLST和cgSNP分析显示,共有30种不同的序列型(sequencetypes,STs),其中20种为新分配的STs。结论汕头市水产品中非O1/O139群霍乱弧菌携带多种毒力基因和耐药基因,其中霍乱弧菌携带blaNDM-1基因为国内首次报道。不同物种来源的菌株遗传多样性高,发现大量新STs型。
基金funded by the National Natural Science Foundation of China(Grant No.32300156)the Natural Science Foundation of Jiangsu Province(Grant No.BK20220493).
文摘The widespread occurrence of carbapenem-resistant organisms has garnered significant public attention.Arthro-pods,including flies,are important vectors of multidrug-resistant bacteria.In this study,we reported the simultane-ous carriage of four carbapenem-resistant isolates from different species,namely,Escherichia coli(E.coli),Providencia manganoxydans(P.manganoxydan),Myroides odoratimimus(M.odoratimimus)and Proteus mirabilis(P.mirabilis),from a single fly in China.These isolates were characterized through antimicrobial susceptibility testing,conjuga-tion assays,whole-genome sequencing,and bioinformatics analysis.M.odoratimimus showed intrinsic resistance to carbapenems.The mechanisms of carbapenem resistance in E.coli,P.manganoxydans,and P.mirabilis were due to the production of NDM-5,NDM-1 and NDM-1,respectively.Genetic context of the bla_(NDM) genes in these three isolates varied.The bla_(NDM-5) gene in E.coli was located on an IncHI2/HI2A multidrug-resistant plasmid,which was con-jugatively transferable.The bla_(NDM-1) gene in P.mirabilis resided on the pPM14-NDM_123k-like nonconjugative plasmid.The bla_(NDM-1) gene in P.manganoxydans was found in a nonconjugatively transferable,multidrug-resistant region.The results of this study enhance our understanding of the dissemination of carbapenem-resistant organisms and sug-gest the need for a more comprehensive approach to antibiotic resistance research encompassing humans,animals,and the environment.
基金supported financially by the National Key Research and Science Program of the Ministry of Science and Technology of the People’s Republic of China(2022YFC2303900)the Beijing Natural Science Foundation(7232242).
文摘Antimicrobial resistance(AMR)has become a critical global public health challenge in the 21st century.Since the initial isolation of a blaNDM-1-carrying and carbapenem-resistant Klebsiella pneumoniae from an Indian hospital in 2009[1],the escalating prevalence of New Delhi metallo-β-lactamase(NDM)-encoding genes(blaNDM)has transformed carbapenem resistance into a worldwide phenomenon,transcending national and regional boundaries[2].Up to 90 distinct NDM variants have been reported globally according to the NCBI GenBank Pathogens database.Plasmidmediated horizontal gene transfer(HGT),which occurs both within and across bacterial species,has significantly accelerated the global dissemination of blaNDM-related genes and the associated resistance[3].Carbapenem-resistant pathogens were responsible for 200,000 deaths globally in 2019[4].Although NDM-1 has been relatively well characterized[5],the epidemiological profiles of other NDM variants require continued surveillance and indepth investigation.The novel NDM-9 variant(GenBank accession no.KC999080)was first identified in 2013 from a clinically significant isolate of Klebsiella pneumoniae ST107 strain PPH1303 with a high level of resistance to carbapenems recovered from the urine culture of a pediatric patient in Beijing,China,who had acute lymphocytic leukemia and had undergone allogeneic stem cell transplantation[6].
