Journal of global antimicrobial resistance最新文献

{"title":"High prevalence of hypervirulent Staphylococcus aureus CC22-t309 in Pediatric Osteomyelitis and Septic Arthritis in China.","authors":"Xiaoying Ye, Huiwen Li, Naike Wang, Haodong Zhang, Chuanqing Wang, Pan Fu, Bo Ning","doi":"10.1016/j.jgar.2026.09.014","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.014","url":null,"abstract":"<p><strong>Objectives: </strong>This study aimed to elucidate the molecular epidemiology, virulence factors, and antimicrobial resistance profiles of Staphylococcus aureus isolated from children with osteomyelitis and septic arthritis (OM-SA) in China.</p><p><strong>Methods: </strong>A total of 68 S. aureus isolates were collected from pediatric patients with OM-SA in Shanghai, China, with 100 strains from children with other infections serving as controls. We performed a systematic analysis on all strains by integrating clinical metadata, whole-genome sequencing, and antimicrobial susceptibility testing.</p><p><strong>Results: </strong>Among S. aureus isolates from OM-SA cases, CC22-t309 was the dominant clone (32.3%), followed by CC59-t437 (17.6%). The prevalence of CC22-t309 in OM-SA was much higher than that in the control (32.3% vs. 8.0%, p<0.001). OM-SA patients with CC22-t309 infection presented much higher inflammatory markers than those infected with other clones (p<0.05). Notably, CC22-t309 from OM-SA exhibited higher carriage of virulence factors, including Panton-Valentine leukocidin (pvl, 100%), collagen adhesin (cna, 86.4%), and fibronectin-binding proteins (fnbA/B, 77.3%), compared with other clones (pvl, 0∼66.7%; cna, 0∼13.8%; fnbA/B, 0∼24.1%; p < 0.05). Within CC22-t309 clone, the carriage of pvl, fnbB and fnbA showed no difference between OM-SA and control group (pvl: 100% vs. 87.5%; fnbB: 77.3% vs. 85.7%; fnbA: 77.3% vs. 37.5%; p >0.05). However, the prevalence of cna in OM-SA was significantly higher than that in the control group (86.4% vs. 37.5%, p = 0.015). Furthermore, CC22-t309 isolates displayed a multidrug-resistant phenotype against β-lactams, macrolides, and lincosamides.</p><p><strong>Conclusion: </strong>We identify the hypervirulent and multidrug-resistant CC22-t309 as a high-risk S. aureus lineage associated with pediatric OM-SA.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194586","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":"MSMEI_4050 modulates resistance to the antitubercular drug rifampicin in Mycolicibacterium smegmatis.","authors":"Ana Leticia Arriaga-Guerrero, Ana Laura Granados-Tristán, Lizeth Mota-Cerecero, Carlos Eduardo Hernández-Luna, Mauricio Carrillo-Tripp, Aldo Herrera-Rodulfo, Patricia Nefertari Ramírez-Flores, Laura Adiene González-Escalante, Brenda Leticia Escobedo-Guajardo, María Elena Camacho-Moll, Beatriz Silva-Ramírez, Roberto Mercado-Hernández, Mario Bermúdez de León, Katia Peñuelas-Urquides","doi":"10.1016/j.jgar.2026.10.004","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.10.004","url":null,"abstract":"<p><strong>Objectives: </strong>Drug-resistant tuberculosis increases the risk of first-line drugs failure, and one strategy involves the identification of new molecular mechanisms of drug resistance. Mycobacterium tuberculosis lipases play a role in the synthesis of bacterial cell wall lipids. In addition, different studies have shown that lipases are associated with drug resistance. The NLH-H protein (Rv1399c) from M. tuberculosis has been characterized, and its overexpression decreases susceptibility to tetrahydrolipstatin. The MSMEI_4050 gene of Mycolicibacterium smegmatis encoded a protein which has more than 30% identity with the NLN-H protein and shares the SER-ARG-HIS catalytic triad. The aim of this study was to evaluate the effect of MSMEI_4050 expression on drug resistance in M. smegmatis as a M. tuberculosis model.</p><p><strong>Methods: </strong>MSMEI_4050 gene overexpression and inhibition were achieved by using the pMV261 vector and CRISPR interference system, respectively. Confirmation of gene expression was determined using qPCR. To evaluate the effect of MSMEI_4050 expression on drug resistance, resazurin microtiter assays and kinetic growth curves were generated. Additionally, molecular docking modeling assays were performed.</p><p><strong>Results: </strong>The results demonstrated that the overexpression of MSMEI_4050 decreased rifampicin resistance in M. smegmatis, whereas the opposite effect was observed upon MSMEI_4050 inhibition. Molecular docking analysis revealed a positive value of the change in Gibbs free energy estimation between MSMEI_4050 and rifampicin, suggesting that no direct protein‒drug interaction occurs at the active site of the protein.</p><p><strong>Conclusions: </strong>MSMEI_4050 expression is associated with rifampicin resistance; further studies are needed to understand the role of MSMEI_4050 in the mechanism underlying rifampicin resistance.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194593","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":"Eleven-year surveillance of Pseudomonas aeruginosa infections and antimicrobial resistance trends in a Portuguese tertiary hospital, 2014 - 2024: Trends and insights into novel agents.","authors":"Diogo Mendes Pedro, Maria Meneses, Carla Mimoso Santos, Ana Bruschy Fonseca, Álvaro Ayres Pereira, Emília Valadas, José Melo Cristino, Cátia Caneiras","doi":"10.1016/j.jgar.2026.09.017","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.017","url":null,"abstract":"<p><strong>Background: </strong>Pseudomonas aeruginosa is a frequent hospital-associated pathogen, often causing severe infections with limited treatment options due to increasing prevalence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. This study evaluated its prevalence and resistance patterns in a large tertiary hospital.</p><p><strong>Methods: </strong>A retrospective observational study analysed all P. aeruginosa clinical isolates collected over 11 years (2014-2024) from inpatients and outpatients. Antimicrobial susceptibility testing included carbapenems, cephalosporins, piperacillin-tazobactam, aztreonam, aminoglycosides, ciprofloxacin, fosfomycin, colistin, ceftolozane-tazobactam and ceftazidime-avibactam.</p><p><strong>Results: </strong>A total of 22883 P. aeruginosa isolates were analysed, representing 16802 episodes from 9978 patients. Mean patient age was 60.9 ±24.7 years, with male predominance. The prevalence of P. aeruginosa among hospitalized patients was 3.0%. Overall, 11.9% of isolates were MDR, 3.3% XDR and 84.8% non-MDR, with MDR and XDR rates increasing over time (p<0.05). A difficult-to-treat phenotype was present in 4.2%. Resistance to at least one carbapenem was observed in 19.0% of isolates, and to ciprofloxacin in 20.3%. Susceptibility to piperacillin-tazobactam, meropenem, ceftazidime, and amikacin remained above 80%. Most isolates non-susceptible to piperacillin-tazobactam or ceftazidime remained susceptible to amikacin, supporting amikacin-containing combination regimens in high-risk settings. Colistin resistance remained below 1%. Among MDR isolates, susceptibility to ceftazidime-avibactam decreased between 2017 and 2024 (100.0% to 83.7%, p<0.05), whereas ceftolozane-tazobactam susceptibility fluctuated over time (83.1% to 88.2%, p<0.05).</p><p><strong>Conclusions: </strong>These findings reveal a shifting resistance landscape and underscore the need for sustained surveillance, antimicrobial stewardship, and updated empirical treatment strategies, while highlighting a critical gap in contemporary epidemiological data.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149194633","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 Diagnostic Accuracy of Xpert Carba-R and NG-Test CARBA-5 for Carbapenemase Detection in Carbapenem-Resistant Enterobacterales: A Systematic Review and Meta-Analysis.","authors":"Ahmed J Alzahrani","doi":"10.1016/j.jgar.2026.10.002","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.10.002","url":null,"abstract":"<p><strong>Background: </strong>Carbapenem-resistant Enterobacterales (CRE) pose a critical public health threat, with carbapenemase-producing organisms driving treatment failures and nosocomial outbreaks. Xpert Carba-R (PCR-based) and NG-Test CARBA-5 (immunochromatographic) are widely adopted rapid diagnostics, yet no meta-analysis has compared their performance.</p><p><strong>Methods: </strong>We conducted a systematic review and meta-analysis following PRISMA 2020 guidelines, searching PubMed, EMBASE, and Cochrane Library (January 2016-December 2024). Two independent reviewers screened studies, extracted data, and assessed quality using QUADAS-2. Pooled sensitivity and specificity were estimated using bivariate random-effects models with SROC curves. Publication bias was evaluated using Deeks' funnel plot and Egger's regression.</p><p><strong>Results: </strong>Twenty studies met inclusion criteria: 12 evaluating Xpert Carba-R (4,735 samples) and 8 evaluating NG-Test CARBA-5 (3,344 samples); 88% were rated at low risk of bias. Xpert Carba-R demonstrated pooled sensitivity of 99.9% (95% CI: 99.8-100.0%), specificity of 98.4% (95% CI: 97.9-98.9%), AUC of 0.998, and low heterogeneity (I²=15%). NG-Test CARBA-5 showed sensitivity of 98.9% (95% CI: 98.4-99.4%), specificity of 96.3% (95% CI: 95.4-97.2%), AUC of 0.987, and moderate heterogeneity (I²=24%). Xpert Carba-R demonstrated statistically higher diagnostic accuracy (p<0.001), though absolute differences were small (1-2 percentage points). No publication bias was detected (Egger's p=0.18 and p=0.24, respectively).</p><p><strong>Conclusions: </strong>Both platforms demonstrate excellent carbapenemase detection accuracy. Xpert Carba-R offers marginally superior performance but requires 50-60 minutes and specialized equipment; NG-Test CARBA-5 delivers results in 15 minutes with minimal infrastructure. Platform selection should integrate local epidemiology, carbapenemase subtypes, and cost. Emerging KPC-2-derived variants with altered epitopes may reduce immunochromatographic accuracy, warranting molecular confirmation in high-risk settings.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182354","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":"Unexplained Colistin Resistance in Klebsiella pneumoniae: Insights into sRNA-Mediated Post-Transcriptional Regulation.","authors":"Humberto Torres-Rodríguez, Luis Esaú López-Jácome, Carlos Córdova-Fletes, Ulises Garza-Ramos, Elvira Garza-González","doi":"10.1016/j.jgar.2026.09.012","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.012","url":null,"abstract":"<p><p>Colistin is a last-resort antibiotic used to treat infections caused by multidrug-resistant Gram-negative pathogens, including Klebsiella pneumoniae. Resistance to colistin can be explained by canonical mechanisms involving chromosomal mutations that activate lipid A modification pathways or by acquisition of plasmid-mediated mcr genes. These mechanisms modify the net charge of the bacterial outer membrane, reducing the binding affinity of colistin. However, an increasing number of genomic surveillance studies report colistin-resistant K. pneumoniae isolates that lack detectable alterations in known resistance mechanisms. This genotype-phenotype discordance suggests that additional regulatory mechanisms may contribute to colistin resistance. This review evaluates the hypothesis that mutation-independent regulatory changes within the PhoP/PhoQ-PmrA/PmrB-CrrA/CrrB signaling network may alter the output of lipid A modification pathways in isolates lacking detectable canonical resistance determinants. This model remains to be experimentally validated. The role of small regulatory RNAs (sRNAs) as potential post-transcriptional modulators of regulatory networks involved in envelope remodeling and antimicrobial susceptibility is explored as a potential explanation for this genotype-phenotype discordance. Finally, experimental approaches including transcriptomics, RNA-RNA interaction mapping, and functional validation are discussed as strategies to study sRNA-mediated regulatory networks. Understanding these regulatory mechanisms may help explain unresolved resistance phenotypes and refine antimicrobial resistance surveillance frameworks.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182464","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":"Outpatient Parenteral Antimicrobial Therapy (OPAT) Guidelines: A Systematic Review.","authors":"Audrey Huili Lim, Norazida Ab Rahman, Afra Nahdia Marizan Nor, Nor Arisah Misnan","doi":"10.1016/j.jgar.2026.09.015","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.015","url":null,"abstract":"<p><strong>Background: </strong>To guarantee the safe and effective provision of Outpatient Parenteral Antimicrobial Therapy (OPAT), appropriate practice guidelines are essential for offering the necessary recommendations. This study aims to synthesise and appraise published OPAT clinical practice guidelines.</p><p><strong>Method: </strong>Bibliographic databases were systematically searched for OPAT guidelines from inception to 14 July 2026, complemented by hand-searching. All guidelines in English were included. Reporting and methodological quality were evaluated using the RIGHT and AGREE II tools. Correlations between AGREE II and RIGHT domain scores were investigated using Spearman's correlation. Inter-rater agreement was assessed using intraclass correlation coefficients estimated with a two-way random effects model.</p><p><strong>Results: </strong>Seven guidelines met the eligibility criteria. Almost all guidelines were published or revised within the last ten years, with the earliest one release in 2004 and the most recent one was published in 2026. Most guidelines aimed to standardise the delivery, safety, and effectiveness of OPAT in their respective healthcare settings. The average overall score for methodological quality of the guidelines from AGREE II was 81.0% while the average overall reporting quality score of the guidelines using the RIGHT instrument was 61.6%. There was an overall positive correlation between AGREE II and RIGHT domain scores.</p><p><strong>Conclusion: </strong>The OPAT guidelines have substantial heterogeneity in methodological quality and reporting completeness. While clear clinical recommendations were noted, lack of evidence syntheses methods and quality assurance were identified. Robust and transparent OPAT guidelines are critical to ensure safe, sustainable, and equitable expansion of outpatient antimicrobial care worldwide.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182448","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":"Exploring the evidence for use of cefiderocol as part of combination therapies: a systematic review of in vitro, in vivo, and clinical studies.","authors":"Marco Meroi, Juan Antonio Del Castillo Polo, Rebecca Scardellato, Alessandra Nazeri, Alessia Savoldi, Renata Da Costa, Laura Piddock, Jennifer Cohn, Evelina Tacconelli, Matteo Morra, Elda Righi","doi":"10.1016/j.jgar.2026.09.016","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.016","url":null,"abstract":"<p><strong>Background: </strong>Cefiderocol is a siderophore cephalosporin with potent activity against carbapenem-resistant Gram-negative bacteria (CR-GNB). While monotherapy is recommended for susceptible Enterobacterales and Pseudomonas aeruginosa, the role of cefiderocol-based combination therapy remains uncertain. We conducted a systematic review of preclinical and clinical evidence supporting cefiderocol combination regimens.</p><p><strong>Methods: </strong>MEDLINE, ESCMID global and IDWeek sources (January 2015-January 2025) were systematically searched for in vitro, in vivo and clinical studies evaluating cefiderocol-based combinations. Randomised trials, observational studies and preclinical synergy studies were included. An exploratory random-effects meta-analysis compared cefiderocol monotherapy with combination therapy for mortality, clinical cure and microbiological eradication.</p><p><strong>Results: </strong>Sixty-seven studies were included (34 in vitro, 5 in vivo and 31 clinical). Preclinical data showed enhanced cefiderocol activity when combined with β-lactamase inhibitors, tetracyclines and selected β-lactams, with in vivo models supporting improved bacterial killing and survival for selected combinations. Clinical studies were heterogeneous and frequently confounded. Combination therapy showed no consistent advantage over monotherapy for clinical cure or microbiological eradication, while mortality estimates were highly variable.</p><p><strong>Conclusions: </strong>Cefiderocol combinations show biologically plausible synergy in preclinical models, but current clinical evidence is limited and largely observational, failing to identify combinations that reliably improve patient-centred outcomes.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166928","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":"Association of cirA allelic variation with cefiderocol susceptibility and virulence-associated lineages in Klebsiella pneumoniae.","authors":"Qianbin Dai, Yun Cao, Yuxuan Liu, Chuwen Zhao, Hanxu Hong, Xinyue Dai, Dandan Wei, Yang Liu","doi":"10.1016/j.jgar.2026.09.013","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.09.013","url":null,"abstract":"<p><strong>Background: </strong>Klebsiella pneumoniae comprises multidrug-resistant and hypervirulent lineages, and cefiderocol uptake may partly depend on iron transport receptors such as CirA. However, the clinical distribution and phenotypic relevance of cirA alleles remain unclear.</p><p><strong>Objectives: </strong>To determine whether cirA allelic variation is associated with cefiderocol susceptibility and virulence-related traits in clinical K. pneumoniae isolates.</p><p><strong>Methods: </strong>We analysed 480 non-duplicate clinical isolates for cirA allele, sequence type, capsular locus, β-lactamase genes, cefiderocol MICs by broth microdilution in iron-depleted cation-adjusted Mueller-Hinton broth, siderophore production, virulence score and Galleria mellonella lethality.</p><p><strong>Results: </strong>Five major cirA allelic groups were identified. cirA198 was associated with higher cefiderocol MIC distributions and included all cefiderocol-resistant isolates, which also carried bla_KPC, bla_NDM and bla_SHV, indicating multifactorial reduced susceptibility. In contrast, cirA1 was linked to ST23-KL1 isolates and was associated with higher virulence scores, increased siderophore production and greater lethality in G. mellonella.</p><p><strong>Conclusions: </strong>Major cirA alleles are associated with distinct K. pneumoniae clonal backgrounds: cirA198 with ST11-KL64 multidrug-resistant isolates and elevated cefiderocol MICs, and cirA1 with ST23-KL1 hypervirulence-associated traits. cirA allelic typing may serve as a lineage-associated marker, although isogenic studies are needed to define independent causal roles.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166574","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":"Comparison of the In Vitro Activities of Ceftazidime-avibactam and Ceftolozane-tazobactam against Clinical Isolates of Pseudomonas aeruginosa: ATLAS Global Surveillance Program 2020-2024.","authors":"Mark A Estabrook, Gregory G Stone, Katherine K Perez, James A Karlowsky","doi":"10.1016/j.jgar.2026.10.001","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.10.001","url":null,"abstract":"<p><strong>Objectives: </strong>To provide a descriptive analysis of the in vitro antimicrobial susceptibility testing results for all 39,661 Pseudomonas aeruginosa isolates collected by the ATLAS global surveillance program data from 2020 to 2024 with a focus on ceftazidime-avibactam and ceftolozane-tazobactam activities against carbapenem-resistant and DTR (difficult-to-treat resistance) phenotypes.</p><p><strong>Methods: </strong>MICs were determined using reference CLSI broth microdilution testing and interpreted by 2026 CLSI and EUCAST breakpoints.</p><p><strong>Results: </strong>Ceftazidime-avibactam (90.6% susceptible; MIC₉₀, 8 µg/mL) and ceftolozane-tazobactam (89.8% susceptible; MIC₉₀, 8 µg/mL) demonstrated similar in vitro activities against all P. aeruginosa isolates. Percent susceptible values for ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem were lowest in Africa (ceftazidime-avibactam, 84.6%; ceftolozane-tazobactam, 82.1%; meropenem, 74.0%) and Latin America (86.5%; 84.7%; 69.8%), and highest in North America (94.8%; 95.1%; 81.6%) and the South Pacific (96.2%; 96.3%; 88.9%). Annual percent susceptible values for ceftazidime-avibactam (range, 90.2% in 2023 to 91.6% in 2022) and ceftolozane-tazobactam (range, 89.6% in 2023 to 90.8% in 2022) did not change over the five years studied. Overall, 26.1% of isolates were carbapenem-resistant; 68.0% and 65.6% of carbapenem-resistant isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. A DTR phenotype was present for 8.0% of isolates; 30.4% and 28.5% of DTR isolates were ceftazidime-avibactam-susceptible and ceftolozane-tazobactam-susceptible, respectively. In total, 4,641 of all 39,661 isolates (11.7%) were ceftazidime-avibactam-resistant and/or ceftolozane-tazobactam-nonsusceptible; 67.5% of these isolates were both ceftazidime-avibactam-resistant and ceftolozane-tazobactam-nonsusceptible, 19.6% were ceftolozane-tazobactam-nonsusceptible and ceftazidime-avibactam-susceptible, and 12.9% were ceftazidime-avibactam-resistant and ceftolozane-tazobactam-susceptible.</p><p><strong>Conclusion: </strong>Approximately 90% of global clinical isolates of P. aeruginosa from 2020 to 2024 remained susceptible to ceftazidime-avibactam and ceftolozane-tazobactam.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149169487","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":"Penicillin susceptibility in Staphylococcus aureus from blood isolates- a multicentre surveillance study in Denmark, Iceland, Norway and Sweden.","authors":"Torgny Sunnerhagen, Erika Matuschek, Gunnar Kahlmeter, Oskar Ekelund, Sofia Persson, Andreas Petersen, Mikkel Lindegaard, Ingvild Haugan, Kristján Orri Helgason, Karin Westmo, Kerstin Granlund, Lisa Vennberg, Malin Hagstrand Aldman","doi":"10.1016/j.jgar.2026.10.003","DOIUrl":"https://doi.org/10.1016/j.jgar.2026.10.003","url":null,"abstract":"<p><strong>Background: </strong>Staphylococcus aureus bacteraemia (SAB) remains associated with substantial morbidity and mortality. Interest in penicillin-susceptible S. aureus (PSSA) has re-emerged, but robust epidemiological data and reliable susceptibility testing are needed to guide antibiotic choice.</p><p><strong>Methods: </strong>In this multicentre observational study, clinical microbiology laboratories in Sweden, Denmark, Norway, and Iceland contributed antibiotic susceptibility testing (AST) data for S. aureus blood culture isolates collected over six consecutive months in 2024. All laboratories followed EUCAST breakpoints, with additional confirmatory testing in selected centres.</p><p><strong>Results: </strong>A total of 2,203 isolates were included. SAB incidence ranged from 34.0 to 62 per 100,000 inhabitants annually. Median patient age was 73 years (IQR 59-82), and 63.8% were male. PSSA constituted 32.2% of isolates, methicillin-resistant S. aureus (MRSA) 2.2%, while methicillin-susceptible, penicillin-resistant isolates comprised 65.6%. Among isolates with penicillin zone diameter ≥26 mm, 97.7% were penicillin-susceptible; 2.3% were resistant based on zone edge characteristics and/or blaZ detection. Resistance to non-β-lactams was low overall but higher among MRSA isolates.</p><p><strong>Conclusions: </strong>PSSA comprises a substantial proportion of SAB isolates in the Nordic countries, supporting routine susceptibility testing and more targeted use of benzylpenicillin.</p>","PeriodicalId":15936,"journal":{"name":"Journal of global antimicrobial resistance","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2026-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168123","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}