Jiming Wu , Longjin Liu , Jianmin Wang , Ying Wang , Xinhui Li , Xiaoyu Wang , Shan Jiang , Wengang Li , Jisheng Zhang , Xiaoli Zhang
{"title":"携带 mcr-9 的耐碳青霉烯类肠杆菌对多粘菌素的诱导抗性转录组分析。","authors":"Jiming Wu , Longjin Liu , Jianmin Wang , Ying Wang , Xinhui Li , Xiaoyu Wang , Shan Jiang , Wengang Li , Jisheng Zhang , Xiaoli Zhang","doi":"10.1016/j.jgar.2024.04.006","DOIUrl":null,"url":null,"abstract":"<div><h3>Objectives</h3><p>Polymyxins are currently the last-resort treatment against multi-drug resistant Gram-negative bacterial infections, but plasmid-mediated mobile polymyxin resistance genes (<em>mcr</em>) threaten its efficacy, especially in carbapenem-resistant <em>Enterobacter cloacae</em> complex (CRECC). The objective of this study was to provide insights into the mechanism of polymyxin-induced bacterial resistance and the effect of overexpression of <em>mcr-9</em>.</p></div><div><h3>Methods</h3><p>The clinical strain CRECC414 carrying the <em>mcr-9</em> gene was treated with a gradient concentration of polymyxin. Subsequently, the broth microdilution was used to determine the minimum inhibitory concentration (MIC) and RT-qPCR was utilized to assess <em>mcr-9</em> expression. Transcriptome sequencing and whole genome sequencing (WGS) was utilized to identify alterations in strains resulting from increased polymyxin resistance, and significant transcriptomic differences were analysed alongside a comprehensive examination of metabolic networks at the genomic level.</p></div><div><h3>Results</h3><p>Polymyxin treatment induced the upregulation of <em>mcr-9</em> expression and significantly elevated the MIC of the strain. Furthermore, the WGS and transcriptomic results revealed a remarkable up-regulation of <em>arnBCADTEF</em> gene cassette, indicating that the Arn/PhoPQ system-mediated L-Ara4N modification is the preferred mechanism for achieving high levels of resistance. Additionally, significant alterations in bacterial gene expression were observed with regards to multidrug efflux pumps, oxidative stress and repair mechanisms, cell membrane biosynthesis, as well as carbohydrate metabolic pathways.</p></div><div><h3>Conclusion</h3><p>Polymyxin greatly disrupts the transcription of vital cellular pathways. A complete PhoPQ two-component system is a prerequisite for polymyxin resistance of <em>Enterobacter cloacae</em>, even though <em>mcr-9</em> is highly expressed. These findings provide novel and important information for further investigation of polymyxin resistance of CRECC.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524000791/pdfft?md5=dffa1c5a554d153cdf5659432b53eb4d&pid=1-s2.0-S2213716524000791-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Transcriptomic analysis of induced resistance to polymyxin in carbapenem-resistant Enterobacter cloacae complex isolate carrying mcr-9\",\"authors\":\"Jiming Wu , Longjin Liu , Jianmin Wang , Ying Wang , Xinhui Li , Xiaoyu Wang , Shan Jiang , Wengang Li , Jisheng Zhang , Xiaoli Zhang\",\"doi\":\"10.1016/j.jgar.2024.04.006\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Objectives</h3><p>Polymyxins are currently the last-resort treatment against multi-drug resistant Gram-negative bacterial infections, but plasmid-mediated mobile polymyxin resistance genes (<em>mcr</em>) threaten its efficacy, especially in carbapenem-resistant <em>Enterobacter cloacae</em> complex (CRECC). The objective of this study was to provide insights into the mechanism of polymyxin-induced bacterial resistance and the effect of overexpression of <em>mcr-9</em>.</p></div><div><h3>Methods</h3><p>The clinical strain CRECC414 carrying the <em>mcr-9</em> gene was treated with a gradient concentration of polymyxin. Subsequently, the broth microdilution was used to determine the minimum inhibitory concentration (MIC) and RT-qPCR was utilized to assess <em>mcr-9</em> expression. Transcriptome sequencing and whole genome sequencing (WGS) was utilized to identify alterations in strains resulting from increased polymyxin resistance, and significant transcriptomic differences were analysed alongside a comprehensive examination of metabolic networks at the genomic level.</p></div><div><h3>Results</h3><p>Polymyxin treatment induced the upregulation of <em>mcr-9</em> expression and significantly elevated the MIC of the strain. Furthermore, the WGS and transcriptomic results revealed a remarkable up-regulation of <em>arnBCADTEF</em> gene cassette, indicating that the Arn/PhoPQ system-mediated L-Ara4N modification is the preferred mechanism for achieving high levels of resistance. Additionally, significant alterations in bacterial gene expression were observed with regards to multidrug efflux pumps, oxidative stress and repair mechanisms, cell membrane biosynthesis, as well as carbohydrate metabolic pathways.</p></div><div><h3>Conclusion</h3><p>Polymyxin greatly disrupts the transcription of vital cellular pathways. A complete PhoPQ two-component system is a prerequisite for polymyxin resistance of <em>Enterobacter cloacae</em>, even though <em>mcr-9</em> is highly expressed. 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Transcriptomic analysis of induced resistance to polymyxin in carbapenem-resistant Enterobacter cloacae complex isolate carrying mcr-9
Objectives
Polymyxins are currently the last-resort treatment against multi-drug resistant Gram-negative bacterial infections, but plasmid-mediated mobile polymyxin resistance genes (mcr) threaten its efficacy, especially in carbapenem-resistant Enterobacter cloacae complex (CRECC). The objective of this study was to provide insights into the mechanism of polymyxin-induced bacterial resistance and the effect of overexpression of mcr-9.
Methods
The clinical strain CRECC414 carrying the mcr-9 gene was treated with a gradient concentration of polymyxin. Subsequently, the broth microdilution was used to determine the minimum inhibitory concentration (MIC) and RT-qPCR was utilized to assess mcr-9 expression. Transcriptome sequencing and whole genome sequencing (WGS) was utilized to identify alterations in strains resulting from increased polymyxin resistance, and significant transcriptomic differences were analysed alongside a comprehensive examination of metabolic networks at the genomic level.
Results
Polymyxin treatment induced the upregulation of mcr-9 expression and significantly elevated the MIC of the strain. Furthermore, the WGS and transcriptomic results revealed a remarkable up-regulation of arnBCADTEF gene cassette, indicating that the Arn/PhoPQ system-mediated L-Ara4N modification is the preferred mechanism for achieving high levels of resistance. Additionally, significant alterations in bacterial gene expression were observed with regards to multidrug efflux pumps, oxidative stress and repair mechanisms, cell membrane biosynthesis, as well as carbohydrate metabolic pathways.
Conclusion
Polymyxin greatly disrupts the transcription of vital cellular pathways. A complete PhoPQ two-component system is a prerequisite for polymyxin resistance of Enterobacter cloacae, even though mcr-9 is highly expressed. These findings provide novel and important information for further investigation of polymyxin resistance of CRECC.
期刊介绍：
The Journal of Global Antimicrobial Resistance (JGAR) is a quarterly online journal run by an international Editorial Board that focuses on the global spread of antibiotic-resistant microbes.
JGAR is a dedicated journal for all professionals working in research, health care, the environment and animal infection control, aiming to track the resistance threat worldwide and provides a single voice devoted to antimicrobial resistance (AMR).
Featuring peer-reviewed and up to date research articles, reviews, short notes and hot topics JGAR covers the key topics related to antibacterial, antiviral, antifungal and antiparasitic resistance.
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