Journal of global antimicrobial resistance最新文献

{"title":"Insertion with long target duplication in polymyxin B-induced resistant mutant of Salmonella","authors":"Tongtong Zhang ,&nbsp;Huifen Jiang ,&nbsp;Ying Zhao ,&nbsp;Tingting Yao ,&nbsp;Rui Li","doi":"10.1016/j.jgar.2024.07.002","DOIUrl":"10.1016/j.jgar.2024.07.002","url":null,"abstract":"<div><h3>Objectives</h3><p>A <em>Salmonella enterica</em> subsp. <em>diarizonae</em> (hereafter <em>S. diarizonae</em>) clinical strain S499 demonstrated unique genomic features. The strain S499 was treated with polymyxin B in vitro to investigate the mechanism of resistance.</p></div><div><h3>Methods</h3><p>S499 was treated with polymyxin B by increasing concentration gradually to obtain a resistant mutant S499V. Whole genomes of the two strains were sequenced using Illumina HiSeq X<strong>-</strong>10 and PacBio RS II platforms. Reverse transcription–quantitative polymerase chain reaction (RT-qPCR) was performed to compare the gene expression.</p></div><div><h3>Results</h3><p>The chromosome of strain S499 contained a 40-kb DNA region that was replicated after treatment with polymyxin B and generated a triple tandem DNA repeat region in the chromosome of mutant strain S499V. This repeat region in S499V was flanked by IS<em>1</em> and contained <em>pmrD, pmrG</em>, and <em>arnBCADTEF</em> operon<em>.</em> In comparison to the homologous 40-kb DNA region of strain S499, a few genes in the repeat DNA region of strain S499V contained truncating mutations that generate two open reading frames (ORFs). The expression of <em>pmrD, pmrG</em>, and <em>arnT</em> was significantly upregulated in S499V.</p></div><div><h3>Conclusion</h3><p>The duplication and overexpression of <em>pmrD, pmrG</em>, and <em>arnT</em> operon may be responsible for the polymyxin B resistance of mutant strain S499V.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 231-235"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001334/pdfft?md5=b614bd4747185be867b00655dbb4f751&pid=1-s2.0-S2213716524001334-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141620160","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":"Colistin resistance in ESBL- and Carbapenemase-producing Escherichia coli and Klebsiella pneumoniae clinical isolates in Cambodia","authors":"Mallorie Hide ,&nbsp;Soda Meng ,&nbsp;Sokleaph Cheng ,&nbsp;Anne-Laure Bañuls ,&nbsp;Santy KY ,&nbsp;Chantana YAY ,&nbsp;Denis Laurent ,&nbsp;Gauthier Delvallez","doi":"10.1016/j.jgar.2024.06.017","DOIUrl":"10.1016/j.jgar.2024.06.017","url":null,"abstract":"<div><h3>Objectives</h3><p>Despite the critical importance of colistin as a last-resort antibiotic, limited studies have investigated colistin resistance in human infections in Cambodia. This study aimed to investigate the colistin resistance and its molecular determinants among Extended-spectrum beta-lactamase (ESBL)- and carbapenemase-producing (CP) <em>Klebsiella pneumoniae</em> (<em>K. pneumoniae</em>) and <em>Escherichia coli</em> (<em>E. coli</em>) isolated in Cambodia between 2016 and 2020.</p></div><div><h3>Methods</h3><p><em>E. coli</em> (<em>n</em> = 223) and <em>K. pneumoniae</em> (<em>n</em> = 39) were tested for colistin minimum inhibitory concentration (MIC) by broth microdilution. Resistant isolates were subjected to polymerase chain reaction (PCR) for detection of mobile colistin resistance genes (<em>mcr</em>) and chromosomal mutations in the two-component system (TCS).</p></div><div><h3>Results</h3><p>Eighteen isolates (10 <em>K. pneumoniae</em> and 8 <em>E. coli</em>) revealed colistin resistance with a rate of 5.9% in <em>E. coli</em> and 34.8% in <em>K. pneumoniae</em> among ESBL isolates, and 1% in <em>E. coli</em> and 12.5% in <em>K. pneumoniae</em> among CP isolates. The resistance was associated with <em>mcr</em> variants (13/18 isolates, <em>mcr-1, mcr</em>-<em>3</em>, and <em>mcr-8.2</em>) and TCS mutations within <em>E. coli</em> and <em>K. pneumoniae</em>, with the first detection of <em>mcr-8.2</em> in Cambodia, the discovery of new mutations potentially associated to colistin resistance in the TCS of <em>E. coli</em> (PhoP I47V, PhoQ N352K, PmrB G19R, and PmrD G85R) and the co-occurrence of <em>mcr</em> genes and colistin resistance conferring TCS mutations in 11 of 18 isolates.</p></div><div><h3>Conclusions</h3><p>The findings highlight the presence of colistin resistance in ESBL- and CP- <em>Enterobacteriaceae</em> involved in human infections in Cambodia as well as chromosomal mutations in TCS and the emergence of <em>mcr</em>-<em>8.2</em> in <em>E. coli</em> and <em>K. pneumoniae</em>. It underscores the need for continuous surveillance, antimicrobial stewardship, and control measures to mitigate the spread of colistin resistance.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 236-244"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001346/pdfft?md5=baecadd2c501f3b5b9504df2e7990299&pid=1-s2.0-S2213716524001346-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141616621","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":"Transmission of global clones of NDM-producing Enterobacterales and interspecies spread of IncX3 plasmid harbouring blaNDM-5 in Tokyo","authors":"Sohei Harada ,&nbsp;Kotaro Aoki ,&nbsp;Yusuke Nomura ,&nbsp;Yuki Ohama ,&nbsp;Hideki Araoka ,&nbsp;Brian Hayama ,&nbsp;Takayuki Sakurai ,&nbsp;Akihiro Ueda ,&nbsp;Yoshikazu Ishii ,&nbsp;Takeya Tsutsumi","doi":"10.1016/j.jgar.2024.06.020","DOIUrl":"10.1016/j.jgar.2024.06.020","url":null,"abstract":"<div><h3>Objective</h3><p>The aim of this study is to characterise the molecular characteristics of NDM-producing <em>Enterobacterales</em>, which have been on the increase in recent years in Japan, where IMP-producing bacteria are dominant among carbapenemase-producing <em>Enterobacterales</em>.</p></div><div><h3>Methods</h3><p>We collected 21 strains of NDM-producing <em>Enterobacterales</em> detected between 2015 and 2022 at five hospitals in Tokyo and performed illumina whole genome sequencing. For the seven selected strains, nanopore long-read sequencing was also performed to characterise the plasmids harbouring <em>bla</em>_NDM.</p></div><div><h3>Results</h3><p>Fourteen strains were <em>Escherichia coli</em> and all carried <em>bla</em>_NDM-5. Among these strains, eight and three were sequence type (ST) 410 and ST167, respectively, and both groups of strains were spread clonally in different hospitals. Two strains of <em>Klebsiella pneumoniae</em> ST147 carrying <em>bla</em>_NDM-1 were detected in a hospital, and these strains had also spread clonally. The remainder included <em>Enterobacter hormaechei, Klebsiella quasipneumoniae, Citrobacter amalonaticus</em>, and <em>Klebsiella michiganensis</em>. Plasmid analysis revealed that an identical IncX3 plasmid harbouring <em>bla</em>_NDM-5 was shared among four strains of different bacterial species (<em>E. coli, C. amalonaticus, K. michiganensis</em>, and <em>E. hormaechei</em>) detected at the same hospital. In addition, a <em>Klebsiella quasipneumoniae</em> strain detected at a different hospital also carried an IncX3 plasmid with a similar genetic structure.</p></div><div><h3>Conclusions</h3><p>Nosocomial spread of multiple multidrug-resistant global clones and transmission of IncX3 plasmids harbouring <em>bla</em>_NDM-5 among multiple species were detected as the major pathways of spread of NDM-producing <em>Enterobacterales</em> in Tokyo. Early detection of carriers and measures to prevent nosocomial spread are important to prevent further spread of NDM-producing organisms.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 309-316"},"PeriodicalIF":3.7,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001310/pdfft?md5=770ef3f488ae2c9343374e33d636e4fd&pid=1-s2.0-S2213716524001310-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141616624","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":"In vitro evaluation of using ceftazidime/avibactam against carbapenem-resistant Acinetobacter baumannii","authors":"","doi":"10.1016/j.jgar.2024.06.011","DOIUrl":"10.1016/j.jgar.2024.06.011","url":null,"abstract":"<div><h3>Objective</h3><p>Carbapenem-resistant <em>Acinetobacter baumannii</em> (CRAB) is a global concern as effective treatments are very limited. We previously used a modified susceptibility testing approach to predict growth suppression in carbapenem-resistant <em>Enterobacterales</em>, but there are uncertainties about the generalizability of the model. The objective of this study is to verify if a similar approach can be extended to CRAB.</p></div><div><h3>Method</h3><p>A clinical isolate of CRAB resistant to ceftazidime/avibactam (CAZ/AVI, MIC = 32/4 mg/L) was examined. CAZ susceptibility was determined using increasing concentrations of AVI (0–64 mg/L), and MIC reduction was characterized with a sigmoid inhibitory maximum effect (Emax) model. The effectiveness of CAZ/AVI was validated in a hollow fibre infection model (HFIM) over 72 hours, using simulated unbound serum / epithelial lining fluid (ELF) exposures of 2.5 g over 2 hours every 8 hours. Baseline inocula of approximately 5.5 log CFU/mL were examined.</p></div><div><h3>Results</h3><p>An AVI concentration-dependent reduction in CAZ MIC was observed (r² = 0.99). CAZ MIC was dramatically reduced from 512 mg/L (no AVI) to 32 mg/L (AVI = 4 mg/L), and further to 8 mg/L (AVI = 16 mg/L). Pharmacokinetic simulations were satisfactory in the HFIM (r² &gt; 0.96). Bacterial suppression was observed &gt;24 hours with the serum exposure, but not that from the ELF.</p></div><div><h3>Conclusion</h3><p>Using multiple AVI concentrations within the clinically relevant range, our susceptibility testing approach could have better insights of treatment outcome for infections caused by CRAB. This could potentially lead to effective intervention(s) overlooked by conventional susceptibility testing method. This case highlights the importance of site-specific drug exposures on determining treatment outcome.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 252-255"},"PeriodicalIF":3.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001218/pdfft?md5=8babafd4c28563b4fc240c4092c9fde4&pid=1-s2.0-S2213716524001218-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600229","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":"Mutations in the pmrB gene constitute the major mechanism underlying chromosomally encoded colistin resistance in clinical Escherichia coli","authors":"","doi":"10.1016/j.jgar.2024.06.013","DOIUrl":"10.1016/j.jgar.2024.06.013","url":null,"abstract":"<div><h3>Objectives</h3><p>The mechanisms underlying chromosomally encoded colistin resistance in <em>Escherichia coli</em> remain insufficiently investigated. In this study, we investigated the contribution of various <em>pmrB</em> mutations from <em>E. coli</em> clinical isolates to colistin resistance.</p></div><div><h3>Methods</h3><p>The resistance mechanisms in eight <em>mcr</em>-negative colistin-resistant <em>E. coli</em> isolates obtained from a nationwide surveillance program in Taiwan using recombinant DNA techniques and complementary experiments were investigated. The minimal inhibitory concentrations (MICs) of colistin in the recombinant strains were compared with those in the parental strains. The expression levels of <em>pmrA</em> and <em>pmrK</em> (which are part of the <em>pmrCAB</em> and <em>pmrHFIJKLM</em> operons associated with colistin resistance) were measured using reverse transcription-quantitative real-time polymerase chain reaction.</p></div><div><h3>Results</h3><p>In the complementation experiments, various mutated <em>pmrB</em> alleles from the eight <em>mcr</em>-negative colistin-resistant <em>E. coli</em> strains were introduced into an ATCC25922 mutant with a PmrB deletion, which resulted in colistin resistance. The MIC levels of colistin in the most complemented strains were comparable to those of the parental colistin-resistant strains. Increased expression levels of <em>pmrA</em> and <em>pmrK</em> were consistently detected in most complemented strains. The impact for colistin resistance was confirmed for various novel amino acid substitutions, P94L, G19E, L194P, L98R and R27L in PmrB from the parental clinical strains. The detected amino acid substitutions are distributed in the different functional domains of PmrB.</p></div><div><h3>Conclusions</h3><p>Colistin resistance mediated by amino acid substitutions in PmrB is a major chromosomally encoded mechanism in <em>E. coli</em> of clinical origin.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 275-280"},"PeriodicalIF":3.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001231/pdfft?md5=b1f5d54d4b0a2ef910c7bd7fb1e956ad&pid=1-s2.0-S2213716524001231-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600230","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":"Occurrence of multi-carbapenemase-producing Enterobacterales in a tertiary hospital in Madrid (Spain): A new epidemiologic scenario","authors":"","doi":"10.1016/j.jgar.2024.06.012","DOIUrl":"10.1016/j.jgar.2024.06.012","url":null,"abstract":"<div><h3>Introduction</h3><p>Multi-carbapenemase-producing Enterobacterales (M-CPE) are increasingly described. We characterized the M-CPE isolates prospectively recovered in our hospital (Madrid, Spain) over two years (2021–2022).</p></div><div><h3>Methods</h3><p>We collected 796 carbapenem resistant Enterobacterales (CRE) from clinical and surveillance samples. Carbapenemase production was confirmed with phenotypic (immunochromatographic, disk diffusion) and molecular (PCR, WGS) techniques. Antimicrobial susceptibility was evaluated by a standard broth microdilution method. Clinical and demographic data were collected.</p></div><div><h3>Results</h3><p>Overall, 23 M-CPE (10 <em>Klebsiella pneumoniae</em>, 6 <em>Citrobacter freundii complex, 3 Escherichia coli, 2 Klebsiella oxytoca,</em> and 2 <em>Enterobacter hormaechei</em>) isolates were recovered from 17 patients (3% with CPE, 0.26-0.28 cases per 1000 admissions). OXA-48 + KPC-3 (7/23) and KPC-3 + VIM-1 (5/23) were the most frequent carbapenemase combinations. All patients had prior antibiotics exposure, including carbapenems (8/17). High resistance rates to ceftazidime/avibactam (14/23), imipenem/relebactam (16/23) and meropenem/vaborbactam (7/23) were found. Ceftazidime/avibactam + aztreonam combination was synergistic in all metallo-β-lactamase producers. Clonal and non-clonal related isolates were found, particularly in <em>K. pneumoniae</em> (5 ST29, 3 ST147, 3 ST307) and <em>C. freundii</em> (3 ST8, 2 ST125, 1 ST563). NDM-1 + OXA-48 was introduced with the ST147-<em>K. pneumoniae</em> high-risk clone linked to the transfer of a Ukrainian patient. We identified four possible nosocomial clonal transmission events between patients of the same clone with the same combination of carbapenemases (KPC-3 + VIM-1-ST29-<em>K. pneumoniae</em>, NDM-1 + OXA-48-ST147-<em>K. pneumoniae</em> and KPC-2 + VIM-1-ST145-<em>K. oxytoca</em>). Carbapenemase-encoding genes were located on different plasmids, except for VIM-1 + KPC-2-ST145-<em>K. oxytoca</em>. Cross-species transmission and a possible acquisition overtime was found, particularly between <em>K. pneumoniae</em> and <em>E. coli</em> producing OXA-48 + KPC-3.</p></div><div><h3>Conclusion</h3><p>M-CPE is an emerging threat in our hospital. Co-production of different carbapenemases, including metallo-β-lactamases, limits therapeutic options and depicts the need to reinforce infection control measures.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 281-291"},"PeriodicalIF":3.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001267/pdfft?md5=32317470c5c6ad4db875d5b87dd73b91&pid=1-s2.0-S2213716524001267-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600242","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":"Antibiotic resistance characterization, virulence factors and molecular characteristics of Bacillus species isolated from probiotic preparations in China.","authors":"Xin Jin, Ling Zhang, Yu Cao, Zhen Dai, Xiaoming Ge, Rui Cai, Ruirong Wang, Ziyan Hu","doi":"10.1016/j.jgar.2024.06.015","DOIUrl":"https://doi.org/10.1016/j.jgar.2024.06.015","url":null,"abstract":"<p><strong>Objectives: </strong>The aim of this study was to determine the phenotypic and molecular characteristics of antibiotic-resistant Bacillus spp. isolated from probiotic preparations in China.</p><p><strong>Methods: </strong>Bacillus strains were isolated from probiotic preparations and then identified using 16S rDNA sequencing. Drug sensitivity tests were conducted to determine their susceptibility to seven antibiotics. Whole genome sequencing was performed on the most resistant strains, followed by analysis of their molecular characteristics, resistance genes, and virulence factors.</p><p><strong>Results: </strong>In total, we isolated 21 suspected Bacillus species from seven compound probiotics, which were identified by 16S rDNA as 12 Bacillus licheniformis, six Bacillus subtilis and three Bacillus cereus. The determination of antimicrobial susceptibility showed widespread resistance to chloramphenicol (95.2%), erythromycin (85.7%) and gentamicin (42.9%). Whole genome sequencing of seven resistant strains revealed that J-6-A (Bacillus subtilis) and J-7-A (Bacillus cereus) contained a plasmid. The resistance gene analysis revealed that each strain contained more than ten resistance genes, among which J-7-A was the most. The streptomycin resistance gene strA was detected in all strains. The chloramphenicol resistance genes ykkC and ykkD were found in J-1-A to J-5-A and were first reported in Bacillus subtilis. The erythrocin resistance gene ermD was detected in strains J-1-A to J-4-A. There were also more than 15 virulence factors and gene islands (GIs) involved in each strain.</p><p><strong>Conclusions: </strong>These results confirm the potential safety risks of probiotics and remind us to carefully select probiotic preparations containing strains of Bacillus species, especially Bacillus cereus, to avoid the potential spread of resistance and pathogenicity.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clonal expansion of Tn1546-like transposon-carrying vancomycin-resistant Enterococcus faecium, a nationwide study in Taiwan, 2004-2018","authors":"","doi":"10.1016/j.jgar.2024.06.005","DOIUrl":"10.1016/j.jgar.2024.06.005","url":null,"abstract":"<div><h3>Objectives</h3><div>The prevalence of vancomycin-resistant <em>Enterococcus faecium</em> (VREfm) has increased significantly in Taiwan. We investigated the molecular epidemiology of clinical VREfm isolates to increase our understanding on their spread and changes in population structure over a 14-year span.</div></div><div><h3>Methods</h3><div>A total of 1113 <em>E. faecium</em> isolates were collected biennially from 2004 to 2018 in Taiwan. MICs were determined by broth microdilution. Whole-genome sequencing (WGS) was performed on 229 VREfm isolates to characterize their genetic environment of vancomycin resistance and wgMLST was used to investigate their clonal relationship.</div></div><div><h3>Results</h3><div>Among the 229 isolates, ST17 and ST78 predominated, especially during the later years, and their prevalences increased from 14.6% (7/48) and 25.0% (12/48) in 2004–2010 to 47.5% (87/181) and 29.8% (54/181) in 2012–2018, respectively. Four types of <em>vanA</em>-carrying Tn<em>1546</em> variants were detected, with type 1 and type 2 predominated. Type 1 Tn<em>1546</em> contained an addition of IS<em>1251</em>, while type 2 resembled type 1 but had an addition of IS<em>1678</em>. wgMLST revealed several distinct clusters of ST17 and ST78 isolates, with type 1 Tn<em>1546</em>-harbouring ST17-Cluster 16 being the largest and most widespread clones throughout the study years. Type 2 Tn<em>1546</em>-carrying ST78 became a predominant clone (Cluster 21) after 2012. Isolates within these clusters are highly similar despite being from different hospitals, regions, and study year.</div></div><div><h3>Conclusion</h3><div>The increase of VREfm in Taiwan was attributed to horizontal transfer of <em>vanA</em>-carrying Tn<em>1546</em> variants between different STs and spread of persistent clones. This study highlights the importance of integrating WGS into surveillance to combat antimicrobial resistance.</div></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"39 ","pages":"Pages 100-108"},"PeriodicalIF":3.7,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141600228","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 characterization of plasmid-borne colistin resistance variants, mcr-1.1 and mcr-1.26, in multidrug-resistant Escherichia coli isolated from backyard farm animals","authors":"","doi":"10.1016/j.jgar.2024.06.009","DOIUrl":"10.1016/j.jgar.2024.06.009","url":null,"abstract":"","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 194-197"},"PeriodicalIF":3.7,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2213716524001206/pdfft?md5=c1052db4b7c20019fe5ad2300f96260a&pid=1-s2.0-S2213716524001206-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141537920","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":"Favourable effect of clavulanic acid on the minimum inhibitory concentrations of cefixime and ceftibuten in ESBL-producing Escherichia coli and Klebsiella pneumoniae","authors":"","doi":"10.1016/j.jgar.2024.06.008","DOIUrl":"10.1016/j.jgar.2024.06.008","url":null,"abstract":"<div><h3>Objectives</h3><p>The use of cephalosporins combined with clavulanate for the treatment of ESBL-harbouring Enterobacteriaceae has been scarcely described. We aimed to describe the effect of different concentrations of clavulanate in the MIC of cefixime and ceftibuten of ESBL-producing <em>Escherichia coli</em> and <em>Klebsiella pneumoniae</em>.</p></div><div><h3>Methods</h3><p>ESBL-producing <em>E. coli</em> and <em>K. pneumoniae</em> isolates were studied. Fixed concentrations of cefixime and ceftibuten (ranges of 32–0.25 and 64–0.5 ng/ml, respectively) were used. Combinations of cefixime/clavulanate and ceftibuten/clavulanate in different ratios (1:0, 1:1, 2:1, 4:1, 8:1, 16:1, 32:1) were tested. MIC were determined by broth microdilution.</p></div><div><h3>Results</h3><p>A total of 6 ESBL-producing <em>E. coli</em>, 6 ESBL-producing <em>K. pneumoniae</em> and 2 control <em>E. coli</em> were tested. When different quantities of clavulanate were added to cefixime and ceftibuten, greater than two-fold decreases in the MIC were observed. When testing the 1:1 cefixime/clavulanate ratio, 10/12 isolates were susceptible. When the ratios 2:1, 4:1, 8:1 and 16:1 were tested, susceptibility was noted for 9/12, 8/12, 4/12 and 5/12 isolates, respectively. Only 2/12 <em>K. pneumoniae</em> isolates were susceptible when the ratio 32:1 was tested. When testing ceftibuten/clavulanate, all isolates remained susceptible across all experiments.</p></div><div><h3>Conclusions</h3><p>Clavulanic acid has a favourable effect in reducing the MIC of cefixime and ceftibuten in isolates of ESBL-producing <em>E. coli</em> and <em>K. pneumoniae</em>. Combining clavulanate with ceftibuten or cefixime could be a useful treatment strategy.</p></div>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":"38 ","pages":"Pages 212-215"},"PeriodicalIF":3.7,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S221371652400119X/pdfft?md5=937c1a660d7e4927e67f76fcf5a94a65&pid=1-s2.0-S221371652400119X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141468571","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}