Journal of global antimicrobial resistance最新文献

{"title":"Genomic characterization and resistance features of Streptococcus agalactiae isolated from non-pregnant adults in Shandong, China","authors":"Xinyi Gong ,&nbsp;Yan Jin ,&nbsp;Xiao Han ,&nbsp;Xueqi Jiang ,&nbsp;Beibei Miao ,&nbsp;Shuang Meng ,&nbsp;Jingyi Zhang ,&nbsp;Haijian Zhou ,&nbsp;Han Zheng ,&nbsp;Jie Feng ,&nbsp;Juan Li","doi":"10.1016/j.jgar.2024.06.001","DOIUrl":"10.1016/j.jgar.2024.06.001","url":null,"abstract":"<div><h3>Background</h3><p><em>Streptococcus agalactiae</em> is a recognized pathogen that primarily affects infants and pregnant women. However, its increasingly important role in causing invasive infections among non-pregnant adults has become a significant health concern due to the severity and variety of its clinical impacts.</p></div><div><h3>Methods</h3><p>Nonduplicate <em>S. agalactiae</em> clinical strains associated with clinical infections (<em>n</em> = 139) were isolated from non-pregnant adults in Shandong, China. Antibiotic susceptibility testing, whole-genome sequencing and genomic analyses were conducted to characterize the genome and identify resistance features of these strains.</p></div><div><h3>Results</h3><p>The strains exhibited universal susceptibility to penicillin, ampicillin, cefotaxime, meropenem, linezolid and vancomycin. Notably, high resistance rates were observed for erythromycin (91.4%), clindamycin (89.2%), levofloxacin (84.2%), tetracycline (54.0%) and, to a lesser extent, chloramphenicol (12.9%). Serotyping revealed seven serotypes and one non-typeable strain. Serotypes Ia, Ib, III and V predominated, representing 95.7% of the strains. Nineteen sequence types were categorized into seven clonal complexes, with CC10 being the most prevalent at 48.9%. The resistance genes <em>mre</em>A (100%), <em>erm</em>B (70.5%) and <em>tet</em>M (46.0%) were commonly detected. All the isolates carried at least one pilus backbone determinant and one alpha-like protein gene, with the PI-1+PI-2a and the <em>bca</em> gene being the most frequent at 84.2% and 54.7%, respectively.</p></div><div><h3>Conclusions</h3><p>While <em>S. agalactiae</em> strains in non-pregnant adults retain sensitivity to β-lactam antibiotics, the elevated resistance to erythromycin, clindamycin, levofloxacin and tetracycline is concerning. Given the growing elderly population worldwide, the burden of <em>S. agalactiae</em> infections is significant. Continuous surveillance of serotype distribution and antibiotic resistance patterns is imperative for targeted prevention and therapeutic strategies.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001115/pdfft?md5=807d63277c021014341fc48520a1ef17&pid=1-s2.0-S2213716524001115-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141310836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unravelling the genomic characteristics of a Klebsiella quasipneumoniae clinical isolate carrying blaNDM-1","authors":"","doi":"10.1016/j.jgar.2024.05.022","DOIUrl":"10.1016/j.jgar.2024.05.022","url":null,"abstract":"<div><h3>Objective</h3><p>Despite the increasing reports of <em>bla</em>_NDM in <em>Enterobacterales</em> in Brazil, comprehensive whole genome sequencing (WGS) data remain scarce. To address this knowledge gap, our study focuses on the characterization of the genome of an New Delhi Metallo-β-lactamase (NDM)-1-producing <em>Klebsiella quasipneumoniae</em> subsp. <em>quasipneumoniae</em> (KQPN) clinical strain isolated in Brazil.</p></div><div><h3>Methods</h3><p>The antimicrobial susceptibility profile of the A-73.113 strain was performed by agar dilution or broth microdilution following the Brazilian Antimicrobial Susceptibility Testing Committee/European Committee on Antimicrobial Susceptibility Testing recommendations. WGS was performed using the Illumina® NextSeq platform and the generated reads were assembled using the SPAdes software. The sequences obtained were submitted to the bioinformatics pipelines to determine the sequence type, resistome, plasmidome, and virulome.</p></div><div><h3>Results</h3><p>The A-73.113 strain was identified as KQPN and was susceptible to polymyxins (MICs, ≤0.25 µg/mL), tigecycline (MIC, 0.5 µg/mL), ciprofloxacin (MIC, 0.5 µg/mL), and levofloxacin (MIC, 1 µg/mL). WGS analysis revealed the presence of genes conferring resistance to β-lactams (<em>bla</em>_NDM-1, <em>bla</em>_CTX-M-15, <em>bla</em>_OXA-9, <em>bla</em>_OKP-A-5, <em>bla</em>_TEM-1), aminoglycosides [<em>aph(3′)-VI, aadA1, aac(6′)-Ib</em>], and fluoroquinolones (<em>oqxAB, qnrS1, aac(6′)-Ib-cr</em>]. Additionally, the presence of the plasmid replicons Col(pHAD28), IncFIA(HI1), IncFIB(K) (pCAV1099-114), IncFIB(pQil), and IncFII(K), as well as virulence-encoding genes <em>fimABCDEFGHIK</em> (type 1 fimbria), <em>pilW</em> (type IV pili), <em>iutA</em> (aerobactin), <em>entABCDEFS</em>/<em>fepABCDG</em>/<em>fes</em> (Ent siderophores), <em>iroE</em> (salmochelin), and <em>allABCDRS</em> (allantoin utilization) was verified. Furthermore, we found that the A-73.113 strain belongs to ST1040.</p></div><div><h3>Conclusions</h3><p>Here we report the genomic characteristics of an NDM-1-producing KQPN ST1040 strain isolated from blood cultures in Brazil. These data will enhance our comprehension of how this species contributes to the acquisition and dissemination of <em>bla</em>_NDM-1 in Brazilian nosocomial settings.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001103/pdfft?md5=12cf0fac85f82b861c677a2563aeface&pid=1-s2.0-S2213716524001103-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141296159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Rapid Emergence of Colistin Resistance in a Newborn Infected with KPC-2–Producing Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae","authors":"","doi":"10.1016/j.jgar.2024.05.021","DOIUrl":"10.1016/j.jgar.2024.05.021","url":null,"abstract":"<div><h3>Objectives</h3><p>Hypervirulent carbapenem-resistant <em>Klebsiella pneumoniae</em> (hv-CRKp) poses a significant threat to public health. This study reports an infection related to hv-CRKp in a premature infant and reveals its colistin resistance and evolutionary mechanisms within the host.</p></div><div><h3>Methods</h3><p>Three KPC-producing CRKp strains were isolated from a patient with sepsis and CRKp osteoarthritis who had been receiving colistin antimicrobial therapy. The minimum inhibitory concentrations (MICs) of ceftazidime, ceftazidime-avibactam (CAZ-AVI), meropenem, imipenem, tigecycline, amikacin, minocycline, sulfamethoxazole/trimethoprim, ciprofloxacin, levofloxacin, aztreonam, cefepime, cefoperazone/sulbactam, piperacillin/tazobactam, and colistin were determined using the microbroth dilution method. The whole-genome sequencing analysis was conducted to determine the sequence types (STs), virulence genes, and antibiotic resistance genes of the three CRKp strains.</p></div><div><h3>Results</h3><p>Whole-genome sequencing revealed that all three CRKp strains belonged to the ST11 clone and carried a plasmid encoding <em>blaKPC-2</em>. The three strains all possessed the <em>iucABCDiutA</em> virulence cluster, <em>peg-344</em> gene, and <em>rmpA/rmpA2</em> genes, defining them as hv-CRKp. Further experiments and whole-genome analysis revealed that a strain of <em>K. pneuomniae</em> had developed resistance to colistin. The mechanism found to be responsible for colistin resistance was a deletion mutation of approximately 9000 bp including the <em>mgrB</em> gene.</p></div><div><h3>Conclusion</h3><p>This study characterizes colistin resistance of the ST11 clone hv-CRKp during colistin treatment and its rapid evolution within the host.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001097/pdfft?md5=3c9c0bc13fd2c7866f768758e08cac0b&pid=1-s2.0-S2213716524001097-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141288194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genomic and Phylogenomic Characterization of Carbapenem-resistant Pseudomonas aeruginosa ‘High-risk’ Clone O4/ExoS+/ST654 Circulating in Chilean Hospitals","authors":"","doi":"10.1016/j.jgar.2024.05.015","DOIUrl":"10.1016/j.jgar.2024.05.015","url":null,"abstract":"<div><h3>Introduction</h3><p>Carbapenem-resistant <em>Pseudomonas aeruginosa</em> (CRPA) is a serious threat to public health. Globally, carbapenemases-producing CRPA isolates mainly belong to ‘high-risk’ clones; however, the molecular epidemiology of CRPA isolates circulating in Chile are scarce, where this pathogen is the main aetiological agent of ventilator-associated pneumonia.</p></div><div><h3>Objectives</h3><p>To characterize the phylogenomics and molecular features of ST654 CRPA isolates collected in Chile between 2016 and 2022.</p></div><div><h3>Methods</h3><p>Eighty-nine CRPA isolates collected in different Chilean hospitals from clinical specimens between 2005 and 2022 were analysed. Antibiotic susceptibility tests and carbapenemases production were carried out on the CRPA ST654 isolates. Also, they were subjected to whole-genome sequencing, from which in silico analyses were performed.</p></div><div><h3>Results</h3><p>Thirty-four strains (38.2%) belonged to the ST654 high-risk clone, being the most predominant lineage of the collection. Most of these isolates belonged to a subclade including KPC producers that also clustered with strains from Argentina and the United States, whereas few VIM and NDM co-producers clustered in two different smaller subclades. The isolates exhibited a broad resistome encompassing genes mediating resistance to several other clinically relevant drugs. Additionally, all the 34 ST654 isolates were ExoS+ as a virulence factor and associated to the O4-serotype.</p></div><div><h3>Conclusions</h3><p>Our report represents the most comprehensive phylogenomic study of a CRPA high-risk clone ST654 to date. Our analyses suggest that this lineage is undergoing a divergent evolutionary path in Chile, because most of the isolates were KPC producers and were O4 serotype, differing from previous descriptions, which underline the relevance of performing molecular surveillance on this pathogen.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001036/pdfft?md5=4e9de80b0f2d33d69667ef43d780bc70&pid=1-s2.0-S2213716524001036-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141288193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Should we, and how to, optimize cefiderocol administration during severe nosocomial pneumonia due to carbapenem-resistant Acinetobacter baumanii? A viewpoint","authors":"Julien Massol ,&nbsp;Aurélien Dinh ,&nbsp;Katy Jeannot ,&nbsp;Clara Duran ,&nbsp;Frédérique Bouchand ,&nbsp;Anaïs Potron ,&nbsp;Laurent Dortet ,&nbsp;François Jehl","doi":"10.1016/j.jgar.2024.05.014","DOIUrl":"10.1016/j.jgar.2024.05.014","url":null,"abstract":"<div><h3>Objectives</h3><p><em>Acinetobacter baumannii</em> is classified by the centre for Disease Control and Prevention (CDC) as an \"urgent threat\" due to its ability to acquire and develop resistance to multiple classes of antibiotics. As a result, it is one of the most concerning pathogens in healthcare settings, with increasing incidence of infections due to carbapenem-resistant <em>Acinetobacter baumannii</em> (CRAB) associated with high morbidity and mortality rates. Therefore, there are ongoing efforts to find novel treatment options, one of which is cefiderocol. We aim to review available evidence on cefiderocol use for severe nosocomial pneumonia due to carbapenem-resistant <em>Acinetobacter baumannii.</em></p></div><div><h3>Methods</h3><p>A comprehensive review was conducted from 2017 to 2023, covering articles from databases such as Pubmed, Scopus, and Embase, along with conference proceedings from ECCMID 2023. The primary focus was on severe nosocomial pneumonia due <em>A. baumannii</em> and cefiderocol.</p></div><div><h3>Discussion</h3><p>Cefiderocol, targeting periplasmic space Penicillin-Binding Proteins (PBPs) via siderophore transport pathways, exhibits promise against multi-drug resistant Gram-negative bacilli. Its effectiveness in treating CRAB pneumonia remains debated. The CREDIBLE trial reported higher mortality with cefiderocol compared to the best available treatment, while other cohort studies showed contrasting outcomes. Patient variations and pharmacokinetic factors may underlie these discrepancies. The recommended cefiderocol dosage regimen may fall short of desired pharmacokinetic targets, especially in critically ill patients and lung infections. Pulmonary factors hindering cefiderocol's entry into bacteria through iron transporters are overlooked in clinical breakpoints. Optimized dosing or combination regimens may enhance infection site exposure and outcomes.</p></div><div><h3>Conclusions</h3><p>Further research is needed to determine the optimal cefiderocol dosage and administration (mono vs. dual therapy, continuous vs. intermittent infusion), in severe <em>Acinetobacter baumannii</em> nosocomial pneumonia.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":3.7,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001024/pdfft?md5=c2bf8f7a34c11d56e445ecce8e27fbac&pid=1-s2.0-S2213716524001024-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141283883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Letter in response to first case of persistent Stenotrophomonas maltophilia bacteremia due to septic thrombosis successfully treated with a Cefiderocol-containing regimen” [Journal of Global Antimicrobial Resistance 36 (2024) 307-308]","authors":"Gayatree Nayak,&nbsp;Sushree Sarathi,&nbsp;Bijayini Behera,&nbsp;Ashoka Mahapatra,&nbsp;Jayanti Jena,&nbsp;Srujana Mohanty","doi":"10.1016/j.jgar.2024.02.020","DOIUrl":"10.1016/j.jgar.2024.02.020","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524000481/pdfft?md5=de107c57c926f6cc30a0e764a9b59d7a&pid=1-s2.0-S2213716524000481-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “The fexA gene in Campylobacter: whether the spread has occurred among various hosts in eastern China” [Journal of Global Antimicrobial Resistance 36 (2024) 293-300]","authors":"Pingyu Huang ,&nbsp;Chong Chen ,&nbsp;Xiaoqi Zang ,&nbsp;Qinyue Jiang ,&nbsp;Yilin Lv ,&nbsp;Hongyue Lv ,&nbsp;Yanying Qin ,&nbsp;Xinan Jiao ,&nbsp;Jinlin Huang","doi":"10.1016/j.jgar.2024.03.001","DOIUrl":"10.1016/j.jgar.2024.03.001","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524000523/pdfft?md5=c16f3cbed68d904f5fb8e0172116eb9a&pid=1-s2.0-S2213716524000523-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140149731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multidrug-resistant Klebsiella pneumoniae clinical isolates producing NDM- and OXA-type carbapenemase in Nepal","authors":"Satomi Takei ,&nbsp;Yoko Tabe ,&nbsp;Takashi Miida ,&nbsp;Tomomi Hishinuma ,&nbsp;Abdullah Khasawneh ,&nbsp;Teruo Kirikae ,&nbsp;Jeevan B. Sherchand ,&nbsp;Tatsuya Tada","doi":"10.1016/j.jgar.2024.04.008","DOIUrl":"10.1016/j.jgar.2024.04.008","url":null,"abstract":"<div><h3>Objectives</h3><p>The emergence of multidrug-resistant <em>Klebsiella pneumoniae</em> has become a serious problem in medical settings worldwide.</p></div><div><h3>Methods</h3><p>A total of 46 isolates of multidrug-resistant <em>K. pneumoniae</em> were obtained from 2 hospitals in Nepal from October 2018 to April 2019.</p></div><div><h3>Results</h3><p>Most of these isolates were highly resistant to carbapenems, aminoglycosides, and fluoroquinolones with the minimum inhibitory concentrations (MICs) of more than 64 µg/mL. These isolates harboured carbapenemase-encoding genes, including <em>bla</em>_NDM-1, <em>bla</em>_NDM-5, <em>bla</em>_OXA-181 and <em>bla</em>_OXA-232, and 16S rRNA methyltransferase-encoding genes, including <em>armA, rmtB, rmtC,</em> and <em>rmtF</em>. Multilocus sequence typing revealed that 44 of 46 isolates were high-risk clones such as ST11 (2%), ST14 (4%), ST15 (11%), ST37 (2%), ST101 (2%), ST147 (28%), ST231 (13%), ST340 (4%), and ST395 (28%). In particular, ST395 isolates, which spread across medical settings in Nepal, co-harboured <em>bla</em>_NDM-5 and <em>rmtB</em> on IncFII plasmids and co-harboured <em>bla</em>_OXA-181/-232 and <em>rmtF</em> on ColKP3 plasmids. Several isolates harboured <em>bla</em>_OXA-181 or <em>bla</em>_NDM-5 on their chromosomes and multi-copies of <em>bla</em>_NDM-1 or genes encoding 16S rRNA methyltransferases on their plasmids.</p></div><div><h3>Conclusions</h3><p>The presented study demonstrates that the high-risk clones of multidrug-resistant <em>K. pneumoniae</em> spread in a clonal manner across hospitals in Nepal.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524000821/pdfft?md5=e22577e1ac53eeab526351b66832ce63&pid=1-s2.0-S2213716524000821-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140956059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptomic analysis of induced resistance to polymyxin in carbapenem-resistant Enterobacter cloacae complex isolate carrying mcr-9","authors":"Jiming Wu ,&nbsp;Longjin Liu ,&nbsp;Jianmin Wang ,&nbsp;Ying Wang ,&nbsp;Xinhui Li ,&nbsp;Xiaoyu Wang ,&nbsp;Shan Jiang ,&nbsp;Wengang Li ,&nbsp;Jisheng Zhang ,&nbsp;Xiaoli Zhang","doi":"10.1016/j.jgar.2024.04.006","DOIUrl":"10.1016/j.jgar.2024.04.006","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":4.6,"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":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140944977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"International Society of Antimicrobial Chemotherapy (ISAC) News and Information Page","authors":"","doi":"10.1016/j.jgar.2024.05.004","DOIUrl":"https://doi.org/10.1016/j.jgar.2024.05.004","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524000924/pdfft?md5=248229abe2db53037c88e537ca3d177f&pid=1-s2.0-S2213716524000924-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141422919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}