Journal of global antimicrobial resistance最新文献

{"title":"Efficacy and safety of antibiotics in the treatment of multidrug-resistant Acinetobacter baumannii infections: a systematic review and Bayesian network meta-analysis.","authors":"Binh Van Tran, Phi Yen Huynh, Tu Tuan Tran, Bao Bui Hoang, Ka-Wai Tam","doi":"10.1016/j.jgar.2026.04.016","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.016","url":null,"abstract":"<p><strong>Objectives: </strong>This study aims to compare the efficacy and safety of antimicrobial regimens for multidrug-resistant Acinetobacter baumannii (MDR A. baumannii) infections using a Bayesian network meta-analysis (NMA).</p><p><strong>Methods: </strong>The PubMed, Embase, Web of Science, Scopus, and Cochrane Library databases were searched from inception through 6^th January 2025, for randomized controlled trials (RCTs) and cohort studies. The primary outcome was all-cause mortality; secondary outcomes included clinical improvement, microbiological cure, and nephrotoxicity. A random-effects NMA estimated odds ratios (ORs) with 95% credible intervals (CrIs) and ranked regimens using the surface under the cumulative ranking curve (SUCRA).</p><p><strong>Results: </strong>The Bayesian NMA included 10 RCTs and 38 cohort studies (14 regimens; 7,300 patients), with cohorts contributing 80.6% of the data. Compared with tigecycline, cefiderocol-based therapies (combination: OR = 0.41, 95% CrI: 0.22-0.77; monotherapy: OR = 0.44, 95% CrI: 0.27-0.76) and sulbactam-durlobactam (OR = 0.42, 95% CrI: 0.15-1.20) were associated with reduced mortality (very low certainty). Sulbactam-durlobactam also ranked highest for clinical improvement (OR = 5.79, 95% CrI: 1.62-21.46, SUCRA 91.0%) and microbiological cure (OR = 8.66, 95% CrI: 1.92-41.01, SUCRA 98.2%; very low certainty). Colistin-based regimens had the highest nephrotoxicity (combination: OR = 8.21, 95% CrI: 1.41-59.35; monotherapy: OR = 7.75, 95% CrI = 1.81-40.82; very low certainty).</p><p><strong>Conclusions: </strong>Sulbactam-durlobactam ranked highest for clinical improvement and microbiological cure, while cefiderocol-based therapies scored highest for mortality reduction in our NMA. However, the evidence was largely derived from observational studies with very low certainty. Further A. baumannii-specific RCTs are needed to confirm these findings.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147856557","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":"Emergence of mobile RND-type efflux pump gene cluster tmexCD-toprJ on a broad-host-range IncC plasmid in Shewanella species in a water environment.","authors":"Duc Trung Dao, Taichiro Takemura, Ikuro Kasuga, Aki Hirabayashi, Nguyen Thi Nga, Pham Hong Quynh Anh, Nguyen Dong Tu, Le Thi Trang, Pham Duy Thai, Hoang Huy Tran, Haruka Abe, Futoshi Hasebe, Keigo Shibayama, Masato Suzuki","doi":"10.1016/j.jgar.2026.04.005","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.005","url":null,"abstract":"<p><strong>Objectives: </strong>The spread of the mobile resistance-nodulation-division (RND)-type efflux pump tmexCD-toprJ gene cluster that confers multidrug resistance (MDR), including tigecycline resistance, in gram-negative bacteria poses a global public health threat. However, the occurrence of such clinically important antimicrobial resistance genes (ARGs) in the natural environments has not yet been well investigated. In this study, we investigated MDR aquatic bacteria in Vietnam.</p><p><strong>Methods: </strong>A carbapenem- and tigecycline-resistant Shewanella xiamenensis isolate NUITM-VS2 was obtained from urban drainage in Hanoi, Vietnam, in October 2021. Antimicrobial susceptibility testing using agar dilution and whole-genome sequencing (WGS) was performed using both long-read and short-read sequencers. ARGs and plasmid replicons were detected using ResFinder and PlasmidFinder with the custom sequence database.</p><p><strong>Results: </strong>NUITM-VS2 showed resistance to most antimicrobials tested, including tigecycline, tetracyclines, carbapenems, cephalosporins, fluoroquinolone, and aminoglycosides. WGS analysis resulted in the complete genome sequence consisting of one chromosome and five plasmids. A 152.2-kb IncC plasmid, pNUITM-VS2_2, co-carried two mobile tigecycline resistance genes, tet(X4) and tmexCD3-toprJ1b-like gene cluster. In addition, a 24.8-kb untypeable plasmid, pNUITM-VS2_4, carried the carbapenemase gene bla_NDM-1. pNUITM-VS2_2 was transferred to Escherichia coli by conjugation, which simultaneously conferred high-level resistance against many antimicrobials, including tigecycline.</p><p><strong>Conclusion: </strong>To the best of our knowledge, this is the first report of the detection of the mobile RND-type efflux pump gene cluster tmexCD-toprJ in Shewanella species. Our results provide genetic evidence of the complexity of the dynamics of clinically important ARGs among aquatic bacteria, which could be important reservoirs for ARGs in the natural environment.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147723009","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":"Genomic characterization of a vancomycin-intermediate Staphylococcus aureus (VISA) small colony variant after long-term antibiotic therapy.","authors":"Noriko Urushibara, Meiji Soe Aung, Minoru Sakurada, Kentaro Kaji, Yoshiyuki Sakai, Nobumichi Kobayashi","doi":"10.1016/j.jgar.2026.04.009","DOIUrl":"10.1016/j.jgar.2026.04.009","url":null,"abstract":"<p><strong>Objectives: </strong>Vancomycin (VCM)-intermediate Staphylococcus aureus (VISA) and small-colony variants (SCVs) are clinically important phenotypes that are frequently difficult to treat and commonly encountered in persistent or recurrent infections. We previously reported a VISA strain, HV2019-1, isolated during a relapse episode of pacemaker-associated bloodstream infection. In the present study, we further investigated its phenotypic characteristics and genomic background.</p><p><strong>Methods: </strong>Colony size, hemolytic activity, and pigmentation were quantitatively evaluated. To elucidate the genetic basis underlying the observed phenotype, whole-genome sequencing was performed and compared with that of a VCM-susceptible MRSA strain exhibiting a normal phenotype.</p><p><strong>Results: </strong>HV2019-1 formed small colonies on agar plates and displayed reduced hemolysis and pigmentation, consistent with characteristic features of S. aureus SCVs. Genome analysis identified multiple mutations, including 25 disrupted open reading frames and five missense variants affecting regulatory functions and surface-associated factors. Among these, six genes previously implicated in VISA-related traits were detected. In contrast, no high-impact mutations were observed in metabolic pathways classically linked to SCVs, such as fatty acid, hemin, menadione, or thymidylate biosynthesis.</p><p><strong>Conclusion: </strong>The absence of canonical metabolic defects characteristic of SCVs, together with widespread alterations in regulatory and surface genes, is aligned with the concept that SCVs represent heterogeneous adaptive phenotypes rather than phenotypes defined primarily by specific metabolic deficiencies. The strain described here provides an example of a bacterial response that may contribute to both resistance and persistence under prolonged antibiotic pressure.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":"37-41"},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147698573","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":"Comparative in vitro activity of minocycline, tigecycline, eravacycline, and omadacycline against Acinetobacter baumannii, Stenotrophomonas maltophilia, and the Burkholderia cepacia complex.","authors":"Jia-Ling Yang, Chia-Jui Yang, Yu-Chung Chuang, Jann-Tay Wang, Wang-Huei Sheng, Shan-Chwen Chang","doi":"10.1016/j.jgar.2026.04.013","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.013","url":null,"abstract":"<p><strong>Objectives: </strong>Infections caused by multidrug-resistant non-fermenting Gram-negative bacilli (NFGNB) are therapeutic challenges. This study was aimed to evaluate the in vitro activity of tetracyclines against clinically important NFGNB.</p><p><strong>Methods: </strong>Minimum inhibitory concentrations (MICs) of minocycline, tigecycline, eravacycline, and omadacycline were determined using broth microdilution for 100 non-duplicate clinical isolates each of Acinetobacter baumannii, Stenotrophomonas maltophilia, and the Burkholderia cepacia complex (Bcc) (2021-2023). Minocycline susceptibility was interpreted by the Clinical and Laboratory Standards Institute clinical breakpoint of 1 mg/L. Tigecycline and eravacycline susceptibility was interpreted by nonclinical pharmacokinetic/pharmacodynamic cutoff values of 1 mg/L, given the absence of NFGNB-specific clinical breakpoints.</p><p><strong>Results: </strong>The MIC₅₀/MIC₉₀ (mg/L) for minocycline, tigecycline, eravacycline, and omadacycline were 4/16, 1/4, 0.5/1, and 4/8 for A. baumannii; 0.5/2, 1/4, 1/4, and 8/32 for S. maltophilia; and 2/16, 2/8, 1/4, and 8/32 for Bcc, respectively. For A. baumannii, eravacycline was the most active agent exhibiting 94% susceptibility, significantly higher than minocycline (42%) and tigecycline (55%) (both P <0.001). For S. maltophilia, minocycline ranked first in activity with higher susceptibility (86%) than eravacycline (59%) and tigecycline (54%) (both P <0.001). In Bcc, eravacycline exhibited modest activity with significantly higher susceptibility (67%) than tigecycline (13%) and minocycline (11%) (both P <0.001). MIC correlations between tetracyclines were moderate to strong, but weaker in Bcc than in A. baumannii (P <0.05).</p><p><strong>Conclusion: </strong>Among tested tetracyclines, minocycline was most active against S. maltophilia, whereas eravacycline was most active against A. baumannii and Bcc. These findings highlight the necessity of species-specific susceptibility testing to guide therapy.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147716774","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":"Antimicrobial resistance in complicated urinary tract infections: A retrospective study from a Rehabilitation Center in a resource-limited setting.","authors":"Dao Vu Do, Thi Thanh Huyen Tran, Thị Linh Tran, Quang Du Nguyen, Thai Phuong Truong, Thi Tuyet Mai Nguyen, Minh Vuong Nong, Hong Luong Nguyen","doi":"10.1016/j.jgar.2026.04.004","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.004","url":null,"abstract":"<p><strong>Background: </strong>Antimicrobial resistance (AMR) is a major challenge in complicated urinary tract infections (cUTIs), particularly among high-risk patients in resource-limited settings.</p><p><strong>Methods: </strong>This retrospective study (January 2019- December 2023) analyzes 622 urine culture-positive samples from cUTI patients at a rehabilitation center to investigate pathogen distribution, AMR patterns, and associations with clinical outcomes using descriptive statistics and regression models.</p><p><strong>Results: </strong>Escherichia coli (46%) was the predominant isolate, followed by Klebsiella pneumoniae (16%). Although Enterococcus faecalis and Pseudomonas aeruginosa were less common, their prevalence increased over time. High resistance rates to ciprofloxacin and ceftriaxone were observed in E. coli (69.5%, 74.7%) and K. pneumoniae (60.2%, 58.1%). Carbapenem resistance emerged in P. aeruginosa (51.4%) and K. pneumoniae (37.5%), with prior antibiotic exposure identified as a significant predictor (OR: 2.15; 95% CI:1.33-3.47; p = 0.002). In contrast, E. coli and E. faecalis retained high susceptibility to nitrofurantoin and fosfomycin. Multidrug-resistant (MDR) infections were independently associated with prolonged hospital stay (β = 1.889; p = 0.045).</p><p><strong>Conclusion: </strong>The high prevalence of resistance to first-line agents and emergence of carbapenem resistance underscore the urgent need for antimicrobial stewardship (AMS) interventions. The study suggests specific hospital-setting AMS should be prioritized the judicious use of agents such as nitrofurantoin and fosfomycin, which retain clinical effectiveness. Addressing MDR is crucial as it represents a key modifiable determinant of length of hospital stay in patients with cUTI.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147716780","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":"Analysis of antimicrobial consumption in Peruvian public health services during the COVID-19 pandemic: a GLASS-AMU-based study.","authors":"Marcelo Cardenas, Cirene Santana, Diego Montañez, Guillermo Salvatierra","doi":"10.1016/j.jgar.2026.04.012","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.012","url":null,"abstract":"<p><strong>Objectives: </strong>The COVID-19 pandemic placed unprecedented pressure on health systems and was accompanied by substantial changes in antimicrobial consumption (AMC) worldwide. In Peru, evidence describing national AMC during this period remains limited. This study aimed to describe patterns and temporal trends in AMC within Peruvian public health services between 2019 and 2022.</p><p><strong>Methods: </strong>National consumption data reported to the World Health Organization's GLASS-AMU platform were analysed. AMC was expressed as density in defined daily doses per 1000 inhabitants per day (DID) and stratified by Anatomical Therapeutic Chemical (ATC) group, administration route and AWaRe classification. A descriptive analysis was performed focusing on the distribution of consumption between ATC groups and AWaRe classification.</p><p><strong>Results: </strong>Annual AMC ranged from 7.91 to 12.38 DID during the study period. Consumption declined in 2020 (7.91 DID), followed by a progressive increase and returning to near pre-pandemic levels in 2022. Among orally administered antimicrobials, broad-spectrum penicillins consistently accounted for the largest share of consumption. In contrast, parenteral AMC was predominantly driven by beta-lactamase-sensitive penicillins. Macrolides and third-generation cephalosporin consumption increased during the pandemic period despite the overall reduction in AMC in 2020. Watch class consumption peaked in 2020 before declining through 2022, while Reserve class showed a constant growth.</p><p><strong>Conclusion: </strong>These findings indicate that the COVID-19 pandemic was associated with substantial shifts in AMC patterns within the Peruvian public health system and underscore the need to strengthen antimicrobial stewardship and consumption surveillance in a pandemic and post-pandemic context.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147716816","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":"A metatranscriptome based approach to predict multidrug resistance phenotypes in Klebsiella pneumoniae without culturing.","authors":"Zhoufu Xiang, Jiaojiao Guan, Han Wang, Wanhua Wu, Sijun Chen, Siqi Wang, Zihao Jiang, Yiyi Hu, Miao Xiang, Tingsheng Huang, Hongpan Tian, Yanni Sun, Yirong Li, Wei Hou, Liangjun Chen","doi":"10.1016/j.jgar.2026.04.014","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.014","url":null,"abstract":"<p><strong>Introduction: </strong>Antimicrobial resistance (AMR), particularly multidrug resistance (MDR) in Klebsiella pneumoniae, has emerged as a significant global public health challenge. However, Accurate resistance phenotype prediction remains difficult.</p><p><strong>Methods: </strong>Metatranscriptomic analysis was performed on bronchoalveolar lavage fluid from 31 patients. After removing host and rRNA sequences, antimicrobial resistance genes (ARGs) were identified using the CARD database. ARG expression profiles trained a machine learning model for resistance prediction. Performance was compared to conventional methods (culture, susceptibility testing, whole genome sequencing).</p><p><strong>Results: </strong>Our methodology successfully captured K. pneumoniae in all 31 clinical samples, achieving 100% accuracy. In contrast, conventional methods resulted in two misidentifications, with an accuracy of 93.5%. Furthermore, for resistance phenotype prediction, our machine learning-based model achieved strong results: an AUROC of 0.86 and an F1 score of 0.77 for Carbapenems, and an AUROC of 0.81 and an F1 score of 0.69 for Aminoglycosides. Importantly, the workflow reduced the diagnostic time to 15 hours, compared to the traditional culture-based methods, which require at least 29 hours.</p><p><strong>Conclusion: </strong>These advancements of our approach establish a novel paradigm for rapid AMR detection and position this method as a valuable supplementary tool to support clinical AMR diagnosis and precision antimicrobial stewardship against multidrug-resistant pathogens.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147717077","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":"Plasmid-mediated tigecycline resistance gene tet(X4) in Escherichia coli from patients with diarrhea-predominant irritable bowel syndrome.","authors":"Xuan Wu, Guorong Chen, Lu Yang, Zexun Lv, Chuncai Liang, Yizhu Chen, Yige Wu, Hui Li, Bing Shao","doi":"10.1016/j.jgar.2026.04.011","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.011","url":null,"abstract":"<p><strong>Objectives: </strong>The tigecycline resistance gene tet(X4) poses a growing threat to public health, yet its occurrence in Escherichia coli from patients with diarrhea-predominant irritable bowel syndrome (IBS-D) remains unknown. This study aimed to characterize tet(X4)-harboring isolates and their genetic contexts in this clinical population.</p><p><strong>Methods: </strong>Antimicrobial resistance surveillance was conducted among IBS-D patients in China (2022-2023). Tigecycline-resistant E. coli isolates were screened for tet(X4) by PCR. Antimicrobial susceptibility testing followed CLSI/EUCAST guidelines. Hybrid genome sequencing was performed to characterize plasmids and resistance determinants, and conjugation assays evaluated transferability.</p><p><strong>Results: </strong>Three tet(X4)-positive E. coli isolates (ST641, ST648, ST88) were identified, showing tigecycline MICs of 4-8 µg/mL and multidrug-resistant phenotypes. Genomic sequencing revealed three distinct conjugative plasmids (IncFIB-, IncHI1B/HI1A/IncFIA-type) carrying tet(X4) with additional resistance genes including bla_TEM-1, bla_CTX-M-55, and qnrS1. A novel IS6-floR-ISCR2-tet(X4)-estT-virD4-IS6 cassette was identified, suggesting a potential mechanism for gene mobilization. Conjugation experiments demonstrated plasmid transfer at frequencies of 10^-2-10^-4, accompanied by acquisition of tigecycline resistance.</p><p><strong>Conclusions: </strong>This study provides the first evidence of tet(X4)-carrying E. coli in IBS-D patients and highlights the diversity and mobility of associated plasmids. These findings underscore the need for continued surveillance of plasmid-mediated tigecycline resistance in clinical gastrointestinal populations.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147698774","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":"Emergence and diversity of IncHI2 plasmids co-carrying carbapenemase genes and mcr-9.1/9.2 in Enterobacter hormaechei from a Chinese children's hospital.","authors":"Hongyu Fu, Zhichen Zhu, Mi Zhou, Hong Du, Jing Ling, Lili Huang","doi":"10.1016/j.jgar.2026.04.010","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.010","url":null,"abstract":"<p><strong>Objective: </strong>This study aimed to characterize the IncHI2 plasmids co-harboring carbapenemase genes and mcr-9 genes in carbapenem-resistant Enterobacter hormaechei (CREH) isolated from a children's hospital in Suzhou, China.</p><p><strong>Methods: </strong>Whole-genome sequencing (WGS) was employed to determine the genome sequences of 12 non-duplicate CREH strains. The molecular features of CREH strains and IncHI2 plasmids harboring carbapenemase genes with or without mcr-9 genes were characterized through genomic analysis. Conjugal transfer assay and plasmid stability testing were used to evaluate the transfer ability and stability of IncHI2 plasmids.</p><p><strong>Results: </strong>The genomic analysis revealed that 12 CREH strains all carried carbapenemase genes bla_NDM-1, bla_NDM-5 or bla_IMP-26. Although the sequence types (STs) of these 12 strains were relatively diverse, most of the strains (11/12) carried IncHI2 and IncHI2A replicons. Further plasmid analysis showed that carbapenemase genes bla_IMP-26 and bla_NDM-1 could coexist with mcr-9.1 or mcr-9.2 on IncHI2 plasmids. While the backbones of these IncHI2 plasmids were relatively conserved, the accessory modules carrying the carbapenemase and mcr-9 genes exhibited diverse genetic contexts, involving transposon Tn125, Tn1696 and Tn6725, and integron In27-like, In615b, and In837. Conjugal transfer assay and plasmid stability testing confirmed the transferability and stability of IncHI2 plasmids.</p><p><strong>Conclusions: </strong>This study reports the emergence and diversity of IncHI2 plasmids that co-harbor carbapenemase genes and mcr-9.1/9.2 in E. hormaechei. To our knowledge, this is also the first report of bla_NDM-1 and mcr-9.2 being carried on a single plasmid in China. The prevalence of such evolutionarily diverse and conjugative carbapenemase-encoding IncHI2 plasmids warrants close monitoring.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147698986","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":"Genomic characterization and epidemiological insights into a bla_NDM-1-harboring Citrobacter portucalensis strain isolated from hospital wastewater in China.","authors":"Yawen Zhang, Qiao Li, Fang He, Wenping Lin, Juan Xu, Yan Yu","doi":"10.1016/j.jgar.2026.04.007","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.04.007","url":null,"abstract":"<p><strong>Objectives: </strong>Citrobacter portucalensis is an emerging pathogen of growing clinical and environmental concern. Here, we report the genomic features of a carbapenem-resistant C. portucalensis strain carrying the bla_NDM-1 gene on an IncHI2A-IncHI2-RepA plasmid, isolated from the wastewater of a tertiary hospital in China.</p><p><strong>Methods: </strong>Antimicrobial susceptibility testing was performed using the VITEK2 Gram-negative card and broth microdilution per CLSI guidelines. Illumina NovaSeq short reads and Nanopore MinION long reads were jointly used for sequencing, and hybrid assembly was generated with Unicycler (v0.4.7). MLST, plasmid replicon typing, and ARG detection were conducted using Pathogenwatch and ABRicate (v1.0.1). Phylogenetic analysis of CRNMS3 alongside 52 publicly available C. portucalensis genomes was conducted using a core-genome single-nucleotide polymorphism (SNP)-based approach.</p><p><strong>Results: </strong>The CRNMS3 genome comprises a chromosome and a 364,750 bp multidrug-resistant plasmid harboring bla_NDM-1. The strain displays broad β-lactam and carbapenem resistance and carries 12 antimicrobial resistance genes, most of which, including bla_NDM-1, are plasmid-encoded. Among 52 globally identified bla_NDM-1-positive C. portucalensis genomes, the majority were from China, spanning multiple sequence types, with ST677 being the most prevalent. Phylogenomic analysis revealed close genomic relatedness between human and environmental isolates within some ST677 strains, indicating potential ongoing transmission across ecological reservoirs.</p><p><strong>Conclusion: </strong>In summary, we report a bla_NDM-1-carrying C. portucalensis strain isolated from hospital wastewater in China and analyze the global prevalence of bla_NDM-1 positive C. portucalensis, highlighting its potential for environmental dissemination and the urgent need for coordinated measures to curb bla_NDM-1 spread.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147690455","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}