International Journal of Antimicrobial Agents最新文献

{"title":"Pharmacodynamic interaction of apotransferrin and anti-pseudomonal antibiotics against extensively drug-resistant Pseudomonas aeruginosa in a dynamic PK/PD model","authors":"María M Montero ,&nbsp;Sandra Domene-Ochoa ,&nbsp;Núria Prim ,&nbsp;Carla López-Causapé ,&nbsp;Daniel Echeverria-Esnal ,&nbsp;Luisa Sorlí ,&nbsp;Sonia Luque ,&nbsp;Eduardo Padilla ,&nbsp;Santiago Grau ,&nbsp;Antonio Oliver ,&nbsp;Juan P. Horcajada","doi":"10.1016/j.ijantimicag.2025.107477","DOIUrl":"10.1016/j.ijantimicag.2025.107477","url":null,"abstract":"<div><div><strong>Objectives:</strong> The rise of antibiotic resistance in clinical settings poses a major challenge. Apotransferrin has emerged as a potential non-traditional therapy for combating infections, potentially preventing resistance development while enhancing bactericidal effects. This study evaluated the efficacy of apotransferrin combined with antipseudomonal antibiotics against extensively drug-resistant (XDR) <em>Pseudomonas aeruginosa</em> isolates.</div><div><strong>Methods:</strong> Twenty XDR <em>P. aeruginosa</em> clinical isolates were evaluated. Different apotransferrin concentrations were tested to determine the optimal in vitro concentration. Time-kill assays assessed the combined effects of apotransferrin with meropenem or ceftolozane/tazobactam (C/T). A chemostat model using four selected isolates validated the most effective combinations and monitored resistance emergence.</div><div><strong>Results:</strong> Apotransferrin monotherapy did not reduce bacterial load, but its combination with antipseudomonal antibiotics enhanced efficacy. Meropenem activity improved in 10/20 isolates, and C/T activity in 13/20 compared to antibiotic monotherapy. The chemostat model confirmed synergistic interactions between apotransferrin and C/T in two isolates, with additive effects in two others. This combination outperformed the most effective monotherapy in all isolates, with no emergence of new C/T-resistant strains.</div><div><strong>Conclusions:</strong> In conclusion, the combination of apotransferrin with C/T demonstrated superior in vitro efficacy against XDR <em>P. aeruginosa</em> isolates compared to either treatment alone. These findings suggest that apotransferrin could be a valuable adjunctive therapy, enhancing the antimicrobial effects of existing antibiotics and potentially extending their clinical utility.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107477"},"PeriodicalIF":4.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-talk between signal transduction systems and metabolic networks in bacterial antibiotics resistance and tolerance","authors":"Shuji Gao ,&nbsp;Baobao Liu ,&nbsp;Shuo Yuan ,&nbsp;Yingying Quan ,&nbsp;Shenao Song ,&nbsp;Wenjie Jin ,&nbsp;Yuxin Wang ,&nbsp;Yang Wang","doi":"10.1016/j.ijantimicag.2025.107479","DOIUrl":"10.1016/j.ijantimicag.2025.107479","url":null,"abstract":"<div><div>The comprehensive antibiotic resistance of pathogens signifies the oneset of the “post-antibiotic era”, and the myriad treatment challenges posed by “superbugs” have emerged as the primary threat to human health. Recent studies indicate that bacterial resistance and tolerance development are mediated at the metabolic level by various signalling networks (e.g., quorum sensing systems, second messenger systems, and two-component systems), resulting in metabolic rearrangements and alterations in bacterial community behaviour. This review focuses on current research, highlighting the intrinsic link between signalling and metabolic networks in bacterial resistance and tolerance.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107479"},"PeriodicalIF":4.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic and epidemiological landscape of anaerobic bacteria in Europe, 2020–2023 (ANAEuROBE)","authors":"Matteo Boattini ,&nbsp;Gabriele Bianco ,&nbsp;Paulo Bastos ,&nbsp;Viktoria Eirini Mavromanolaki ,&nbsp;Sofia Maraki ,&nbsp;Anastasia Spiliopoulou ,&nbsp;Vasileios Kakouris ,&nbsp;Yordan Kalchev ,&nbsp;Ana Budimir ,&nbsp;Branka Bedenić ,&nbsp;Zana Rubic ,&nbsp;Monica Licker ,&nbsp;Corina Musuroi ,&nbsp;Emese Juhász ,&nbsp;Katalin Kristóf ,&nbsp;Mateja Pirs ,&nbsp;Ivana Velimirovic ,&nbsp;Michael Berktold ,&nbsp;Adriána Liptáková ,&nbsp;Adriana Krajcikova ,&nbsp;Cristina Costa","doi":"10.1016/j.ijantimicag.2025.107478","DOIUrl":"10.1016/j.ijantimicag.2025.107478","url":null,"abstract":"<div><h3>Introduction</h3><div>Despite being implicated in a wide spectrum of community- and healthcare-acquired infections, anaerobes have not yet been incorporated into systematic surveillance programs in Europe.</div></div><div><h3>Methods</h3><div>We conducted a multicentre retrospective observational study analysing all anaerobic strains isolated from blood cultures in 44 European Hospital Centres over a 4-y period (2020–2023). Diagnostic approach, epidemiology, and antimicrobial susceptibility according to EUCAST v. 15.0 were investigated.</div></div><div><h3>Results</h3><div>Our study included 14,527 anaerobes, most of which were Gram-positive (45%) or Gram-negative (40%) bacilli. MALDI-TOF coupled to mass spectrometry was the most widely used tool for species identification (98%). Antimicrobial susceptibility testing was performed in the vast majority of centres, using mostly gradient diffusion strip (77%) and disk diffusion (45%) methods according to EUCAST guidelines. The most prevalent species were <em>Cutibacterium acnes</em> (18.7%), <em>Bacteroides fragilis</em> (16.3%), <em>Clostridium perfringens</em> (5.3%), <em>Bacteroides thetaiotaomicron</em> (4.2%), <em>Fusobacterium nucleatum</em> (3.5%), and <em>Parvimonas micra</em> (3.4%). <em>C. acnes</em> showed high resistance to benzylpenicillin (18%), clindamycin (39%), and imipenem (19% and 13% by MIC methods and disk diffusion, respectively). <em>B. fragilis</em> showed high resistance to amoxicillin/clavulanate (24%), piperacillin/tazobactam (22% and 14% by MIC methods and disk diffusion, respectively), clindamycin (22% by both MIC methods and disk diffusion), meropenem (13%), and metronidazole (10%, only by disk diffusion). A similar resistance pattern was observed in <em>B. thetaiotaomicron, Bacteroides ovatus</em>, and <em>Parabacteroides distasonis. C. perfringens</em> showed high resistance to clindamycin (69% and 45% by MIC methods and disk diffusion, respectively), while benzylpenicillin and metronidazole maintained over 90% activity. <em>F. nucleatum</em> showed high resistance to benzylpenicillin (11%), while <em>Fusobacterium necrophorum</em> showed alarming rates of resistance to clindamycin (12%), meropenem (16%) and metronidazole (11%).</div></div><div><h3>Conclusions</h3><div>This study presented an up-to-date analysis of the diagnostics and epidemiology of anaerobic bacteria in Europe, providing insights for future comparative analyses and the development of antimicrobial diagnostic and management strategies, as well as the optimization of current antibiotic treatments.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 6","pages":"Article 107478"},"PeriodicalIF":4.9,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical emergence of Providencia zhejiangensis sp. nov. and Providencia xihuensis sp. nov.: Genomic insights into antimicrobial resistance and geographical distribution","authors":"Xu Dong ,&nbsp;Yanghui Xiang ,&nbsp;Ping Shen ,&nbsp;Yonghong Xiao ,&nbsp;Ying Zhang","doi":"10.1016/j.ijantimicag.2025.107484","DOIUrl":"10.1016/j.ijantimicag.2025.107484","url":null,"abstract":"<div><div>Members of the genus <em>Providencia</em> are typically opportunistic pathogens that can cause severe infections in immunocompromised hosts. This study identified two <em>Providencia</em> strains, SKLX146130 and SKLX074055, representing novel species designated as <em>Providencia zhejiangensis</em> sp. nov. and <em>Providencia xihuensis</em> sp. nov., respectively. Both strains were isolated from clinical samples, with <em>P. zhejiangensis</em> displaying extensive drug resistance. Our analysis revealed that <em>P. xihuensis</em> is predominantly from China, whereas <em>P. zhejiangensis</em> has a global presence. Meanwhile, our analyses resolved <em>Providencia huashanensis</em> as a later heterotypic synonym of <em>Providencia xianensis</em>. Notably, the strain SKLX146130 from <em>P. zhejiangensis</em>, characterized by carrying multiple acquired resistance determinants including the carbapenemase gene <em>bla</em>_NDM-1, belongs to a zoonotic subclade. The genomic analyses of the <em>P. zhejiangensis</em> strain SKLX146130 and <em>Providencia xihuensis</em> strain SKLX074055 showed 79.76–84.55% and 79.85–95.85% average nucleotide identity (ANI), respectively, with other <em>Providencia</em> type strains. In silico DNA-DNA hybridization (dDDH) values ranged from 20.7 to 26.2% and 21.3–64.8%, respectively. These results, along with phenotypic characterization and phylogenetic evidence, confirm that SKLX146130 and SKLX074055 represent two distinct novel species within the genus <em>Providencia</em>. Consequently, we propose the names <em>Providencia zhejiangensis</em> sp. nov. and <em>Providencia xihuensis</em> sp. nov. for these species and call for monitoring these species in clinical infections.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107484"},"PeriodicalIF":4.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Posaconazole effectiveness in rare invasive fungal infections: A systematic literature review","authors":"Mark Bernauer ,&nbsp;Hetty Waskin ,&nbsp;Nicole Cossrow ,&nbsp;Allysen Kaminski ,&nbsp;Alyssa Simon ,&nbsp;Havilland Campbell ,&nbsp;Dipen Patel","doi":"10.1016/j.ijantimicag.2025.107482","DOIUrl":"10.1016/j.ijantimicag.2025.107482","url":null,"abstract":"<div><h3>Introduction</h3><div>Mucormycosis, hyalohyphomycosis, chromoblastomycosis, and fungal mycetoma are rare invasive fungal infections (IFIs) that cause significant morbidity and mortality in immunocompromised patients. Few effective treatment options are available for these IFIs.</div></div><div><h3>Methods</h3><div>We performed a systematic literature review of MEDLINE and Embase to identify studies published from 2005 (year of posaconazole approval) to 22 October 2022, reporting the efficacy/effectiveness of posaconazole monotherapy or combination therapy for treating mucormycosis, hyalohyphomycosis, chromoblastomycosis, and mycetoma. Positive outcomes or positive clinical outcomes were defined as reporting of a positive efficacy/effectiveness measure (i.e. no relapse, response, cure, radiological improvement, clinical/symptom improvement, or survived therapy).</div></div><div><h3>Results</h3><div>Of 3207 articles identified (after removing duplicates), 533 articles (mostly case reports) were included. Positive clinical outcomes with posaconazole therapy were observed in most patients with mucormycosis (74.8%, 1197/1601), hyalohyphomycosis (58.5%, 62/106), chromoblastomycosis (90.5%, 19/21), and mycetoma (100%, 5/5). Overall survival was around 70% or greater across the IFIs examined. Positive response was higher in second-line monotherapy than first-line monotherapy in mucormycosis and chromoblastomycosis. Higher mortality was observed with combination therapy than monotherapy in mucormycosis and hyalohyphomycosis infections (except for first-line use in mucormycosis). Positive clinical outcome was 78.6% and overall survival was 78.6% in 323 coronavirus disease-associated mucormycosis infection cases.</div></div><div><h3>Conclusions</h3><div>Despite the rarity of these IFIs, substantial data have been published since posaconazole was initially approved in 2005, and the real-world case reports demonstrate that posaconazole is an effective therapeutic option alone or in combination for the treatment of these rare IFIs.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"66 1","pages":"Article 107482"},"PeriodicalIF":4.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","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.ijantimicag.2025.107481","DOIUrl":"10.1016/j.ijantimicag.2025.107481","url":null,"abstract":"","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 4","pages":"Article 107481"},"PeriodicalIF":4.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhaled alone versus inhaled plus intravenous polymyxin B for the treatment of pneumonia due to carbapenem-resistant gram-negative bacteria: A prospective randomized controlled trial","authors":"Yu Cheng ,&nbsp;Lili Zhou ,&nbsp;Danjie Wang ,&nbsp;Xueyong Li ,&nbsp;Rongqi Lin ,&nbsp;Junnian Chen ,&nbsp;Fuquan Tu ,&nbsp;Yiqin Lin ,&nbsp;Wenwei Wu ,&nbsp;Maobai Liu ,&nbsp;Hui Zhang ,&nbsp;Hongqiang Qiu","doi":"10.1016/j.ijantimicag.2025.107483","DOIUrl":"10.1016/j.ijantimicag.2025.107483","url":null,"abstract":"<div><h3>Objectives</h3><div>Infections due to carbapenem-resistant Gram-negative bacteria (CR-GNB) are associated with considerable morbidity and mortality. Polymyxin B (PMB) is a first-line agent for CR-GNB-associated pneumonia, but limited data exist on the clinical use of inhaled (IH) PMB.</div></div><div><h3>Methods</h3><div>A single-center, prospective randomized controlled trial was conducted in China to compare IH PMB alone with IH plus intravenous (IV) PMB between February 2022 and February 2024. The primary outcome was the clinical cure rate.</div></div><div><h3>Results</h3><div>Twenty-two evaluable patients were assigned to the IH group, and 56 patients were included in the IH+IV group. Baseline characteristics were comparable between the two groups. No significant differences were observed in clinical cure rates, favorable clinical outcomes, microbiological outcomes, all-cause mortality, or pneumonia-related mortality. However, IH PMB alone was associated with a lower incidence of nephrotoxicity (<em>P</em> = 0.030). IH PMB demonstrated significantly higher drug concentrations in the epithelial lining fluid (ELF) compared to systemic administration. Patients with immunosuppressive therapy (OR, 0.066; 95% CI, 0.010–0.433; <em>P</em> = 0.005), malignancies (OR, 0.112; 95% CI, 0.016–0.797; <em>P</em> = 0.029), and higher SOFA scores (OR, 0.693; 95% CI, 0.518–0.929; <em>P</em> = 0.014) were less likely to achieve favorable clinical outcomes. Conversely, higher PMB ELF 1-hour concentrations (OR, 1.085; 95% CI, 1.026–1.148; <em>P</em> = 0.004) were associated with more favorable clinical outcomes. The combination of these four indicators demonstrated excellent diagnostic performance (AUC = 0.882). Plasma 1-hour PMB concentrations showed acceptable predictive performance for nephrotoxicity (AUC = 0.766).</div></div><div><h3>Conclusions</h3><div>The potential benefits of IH PMB outweigh the risks, making it an effective treatment for CR-GNB-associated pneumonia in combination with other empirical antimicrobial agents.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107483"},"PeriodicalIF":4.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Title Page & Editorial Board","authors":"","doi":"10.1016/S0924-8579(25)00031-7","DOIUrl":"10.1016/S0924-8579(25)00031-7","url":null,"abstract":"","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 3","pages":"Article 107473"},"PeriodicalIF":4.9,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143478549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"“Seesaw effect” between daptomycin and ceftobiprole in daptomycin-resistant methicillin-resistant staphylococcus aureus isolates","authors":"Mengzhen Chen ,&nbsp;Shengnan Jiang ,&nbsp;Lu Sun ,&nbsp;Haiping Wang ,&nbsp;Lingfang Di ,&nbsp;Yeqiong Liu ,&nbsp;Ying Zhang ,&nbsp;Hemu Zhuang ,&nbsp;Yueqin Hong ,&nbsp;Zhengan Wang ,&nbsp;Feiteng Zhu ,&nbsp;Yiyi Chen ,&nbsp;Shujuan Ji ,&nbsp;Yunsong Yu ,&nbsp;Yan Chen ,&nbsp;Xiaoxing Du","doi":"10.1016/j.ijantimicag.2025.107469","DOIUrl":"10.1016/j.ijantimicag.2025.107469","url":null,"abstract":"<div><h3>Objectives</h3><div>This study aimed to investigate the “seesaw effect” of daptomycin (DAP) and ceftobiprole (BPR) on DAP-resistant (DAP-R) methicillin-resistant <em>Staphylococcus aureus</em> (MRSA) isolates.</div></div><div><h3>Methods</h3><div>Broth microdilution minimum inhibitory concentrations (MICs) of DAP and BPR were tested for laboratory-derived and clinical DAP-R MRSA isolates to estimate the “seesaw effect.” Time-kill curves for seven representative DAP-R isolates were obtained using DAP and BPR to validate their synergistic activity <em>in vitro</em>. Whole genome sequencing as well as deletion and complementation of the <em>mprF</em> gene were performed to investigate the mechanisms of the “seesaw effect.”</div></div><div><h3>Results</h3><div>The BPR MICs decreased by half-fold in DAP-R MRSA isolates. The synergistic effect of DAP and BPR against representative clinical and community-associated MRSA (CA-MRSA) isolates was demonstrated in time-kill analyses, showing that synergistic activity was preferred in CA-MRSA compared with hospital-associated MRSA. The <em>mprF</em> mutations were identified in isolates exhibiting the “seesaw effect.” These mutations increased the DAP MIC while decreasing the BPR MIC.</div></div><div><h3>Conclusions</h3><div>The “seesaw effect” between DAP and BPR was prevalent among DAP-R MRSA isolates. This phenomenon was associated with the <em>mprF</em> mutations of MRSA.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107469"},"PeriodicalIF":4.9,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal, regional, and demographic differences among antimicrobial-resistant domestic Campylobacter jejuni human infections across the United States, 2013–2019","authors":"Hamid Reza Sodagari ,&nbsp;Mohammad Nasim Sohail ,&nbsp;Csaba Varga","doi":"10.1016/j.ijantimicag.2025.107467","DOIUrl":"10.1016/j.ijantimicag.2025.107467","url":null,"abstract":"<div><div>Human infections with antimicrobial-resistant <em>Campylobacter jejuni</em> increase morbidity, mortality, hospitalization, and treatment costs. Resistance to antimicrobials recommended to treat campylobacteriosis has increased in the United States, despite the mitigating efforts of public health authorities. This study analyzed publicly available antimicrobial resistance (AMR) monitoring data collected by the National Antimicrobial Resistance Monitoring System (NARMS) to assess temporal, regional, and demographic differences in AMR among domestically acquired <em>C. jejuni</em> infections across the United States between 2013 and 2019. Mann–Kendall tests evaluated trends in AMR throughout the study period. Poisson regression models assessed differences in resistance to each antimicrobial class among the years, age groups, and regions. Among the 7624 <em>C. jejuni</em> isolates, high resistance was identified against tetracyclines (n = 3504; 45.96%; 95% CI = 44.84–47.09), and quinolones (n = 2093; 27.45%; 95% CI = 26.45–28.47). An increasing trend in resistance to quinolones (<em>P</em> = 0.07) and a decreasing trend for tetracyclines (<em>P</em> = 0.036) were identified. The rate of isolates that showed resistance to all antimicrobial classes except tetracyclines was significantly higher in the state of Connecticut. Resistance rates for all antimicrobials except aminoglycosides were higher among the 20–39 year age group. Regions and age groups with the greatest AMR rates were identified, which warrants further studies to identify individual and area-level risk factors. To mitigate the burden of antimicrobial-resistant <em>C. jejuni</em> infections, health authorities should focus on regions and age groups with the highest risk.</div></div>","PeriodicalId":13818,"journal":{"name":"International Journal of Antimicrobial Agents","volume":"65 5","pages":"Article 107467"},"PeriodicalIF":4.9,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}