European Journal of Clinical Microbiology & Infectious Diseases最新文献

{"title":"Clinical and serological outcomes of syphilis: an 18-year retrospective cohort study on predictors of treatment response and seroreversion in Türkiye.","authors":"Hatice Sertkaya, Esra Kazak, Ayşe Melda Payaslıoğlu, Uğur Önal, Yasemin Heper, Emel Yılmaz, Emin Halis Akalın","doi":"10.1007/s10096-026-05698-9","DOIUrl":"https://doi.org/10.1007/s10096-026-05698-9","url":null,"abstract":"<p><strong>Purpose: </strong>Despite established protocols, the global resurgence of syphilis remains a public health challenge, with outcomes influenced by disease stage and host factors. This study described 18-year epidemiological trends and identified predictors of serological treatment response and long-term seroreversion.</p><p><strong>Methods: </strong>We retrospectively analyzed 503 adults diagnosed with syphilis between 2005 and 2022 and classified disease stages according to CDC criteria. Treatment response was defined as a ≥ 4-fold decline in rapid plasma reagin (RPR) titers within 12 months for early-stage and 24 months for late-stage syphilis, while seroreversion was defined as a non-reactive RPR. Overall, 157 patients were included in the treatment-response analysis and 159 in the seroreversion analysis, the latter including two additional patients who achieved seroreversion before treatment-response assessment. Independent predictors were identified using multivariable logistic regression.</p><p><strong>Results: </strong>Syphilis cases increased significantly after 2015, with late-stage disease accounting for 75.7% (n = 381) of diagnoses. Early syphilis rose from 10.5% (2005-2015) to 30.2% after 2015 (p < 0.001). Among patients with available HIV test results, 29.4% (134/456) of cases were in people with HIV. Early-stage syphilis was more frequent in people living with HIV (PLWH) than in HIV-negative individuals (32% vs. 20.1%). Among patients with follow-up, 75.2% (118/157) achieved a serological response. In multivariate analysis, late-stage syphilis was a negative predictor of response (OR 0.22, 95% CI 0.07-0.76; p = 0.016), while baseline RPR titers ≥ 1:8 were a strong positive predictor (OR 8.18, 95% CI 1.72-38.85; p = 0.008). HIV status was not independently associated with response (p > 0.05). Seroreversion occurred in 35.8%, with no independent predictors identified.</p><p><strong>Conclusions: </strong>The syphilis burden has grown, driven by delayed diagnosis and late-stage predominance despite recent trends toward earlier detection. In this cohort, disease stage and baseline RPR titers were stronger predictors of serological response than HIV status. The higher frequency of early-stage diagnosis in PLWH is consistent with the potential impact of intensified screening and may reflect differences in healthcare engagement and testing practices compared with the general population.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164901","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":"Clinical burden and outcomes of pediatric carbapenem-resistant Klebsiella pneumoniae bloodstream infections in a tertiary care center.","authors":"Sevliya Öcal Demi̇r, Seyhan Yilmaz, Meryem Çağla Abacı Çapar, Sıla Cura, Faruk Odabaşi, Ahmet Furkan Eser, Ezgi Çelikboya, Arzu İlki̇, Eda Kepenekli̇, Gülşen Akkoç","doi":"10.1007/s10096-026-05697-w","DOIUrl":"https://doi.org/10.1007/s10096-026-05697-w","url":null,"abstract":"<p><strong>Background: </strong>Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an emerging threat in pediatric healthcare settings because of limited treatment options and high morbidity and mortality. However, data regarding pediatric CRKP bloodstream infection (BSI) remain limited. This study aimed to evaluate the clinical characteristics and outcomes of CRKP BSI in children.</p><p><strong>Methods: </strong>A retrospective cohort study was conducted among children hospitalized with Klebsiella pneumoniae BSI between 2020 and 2025. Demographic characteristics, healthcare exposures, laboratory findings, antimicrobial therapy, and clinical outcomes were analyzed.</p><p><strong>Results: </strong>A total of 86 children were included; the median age was 12 months, and 50% were male. Overall, 91.9% had at least one underlying comorbidity, 89.5% had a history of previous hospitalization, 83.3% had prior antibiotic usage, and 25.9% had undergone surgical intervention. During the index hospitalization, 57.0% required intensive care unit admission and 77.6% had at least one invasive device. Fifteen children (17.4%) had CRKP BSI. Prior carbapenem exposure and longer antibiotic use were more frequent in the CRKP group, although the differences were not statistically significant. White blood cell, neutrophil, lymphocyte, and platelet counts were significantly lower in patients with CRKP BSI. Three-month mortality was 40.0% in the CRKP group and 15.9% in the CSKP group, with no statistically significant difference (p = 0.069). Length of hospital stay was also similar between the groups.</p><p><strong>Conclusion: </strong>CRKP accounted for 17.4% of K. pneumoniae BSIs in this pediatric cohort. No independent factor associated with carbapenem resistance was identified. The small number of CRKP cases limited the statistical power of the study. Larger multicenter studies are needed to better define factors associated with CRKP and its clinical outcomes in children.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164895","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":"Characterization of acute dengue immune status and serotype surveillance in three regions of Burkina Faso: a hospital-based cross-sectional study.","authors":"Louis Robert Wendyam Belem, Arsène Zongo, Raymond Karlhis Yao, Christelle Adelaide Zilsamba Lankouande, Armand Vital Wenceslas Taïta, Tarwendpanga François Xavier Ouédraogo, Benewêndê Philippe Kabore, Abdoul Bamogo, Benewêndê Philippe Kabore, Abdoul Bamogo, Raïssa Muriel de Souza, Yacouba Kouadima, Dieudonné Tialla, Antoinette Kaboré, Adama Sanou","doi":"10.1007/s10096-026-05693-0","DOIUrl":"https://doi.org/10.1007/s10096-026-05693-0","url":null,"abstract":"<p><strong>Introduction: </strong>In recent years, dengue has become a significant public health concern in Burkina Faso, associated with severe disease and death. Rapid characterization of acute dengue serostatus is useful for identifying patients at risk, informing transmission dynamics, and supporting public health decision-making. This study aimed to characterize dengue immune status in three regions of Burkina Faso to inform pre-vaccination screening, evaluate a commercial combined DENV NS1, IgM, and IgG rapid diagnostic test (RDT) kit, and investigate DENV serotype circulation.</p><p><strong>Methods: </strong>A multicenter study was conducted between 2023 and 2025 in Bobo-Dioulasso, Houndé, Ouagadougou, and Gaoua. Blood samples were collected from patients with suspected dengue. Acute DENV infections and serotypes were identified using real-time RT-PCR, and immune status was characterized by enzyme-linked immunosorbent assay (ELISA) according to WHO criteria. Serum samples were screened using the reference standard (RT-PCR combined with ELISA) to evaluate the performance of a commercial DENV NS1, IgM, and IgG RDT kit in characterizing dengue immune status.</p><p><strong>Results: </strong>Primary dengue accounted for 75.9%, 80.4%, and 71.4% in 2023, 2024, and 2025, respectively. The sensitivity of the RDT for determining primary and post-primary dengue during the first 5 days of illness was 93.3% and 94.7%, respectively. DENV-1, DENV-2, and DENV-3 accounted for 47.0%, 5.6%, and 47.4% of cases, respectively. DENV-4 was not detected. The diagnostic specificity of the RDT for both primary and post-primary dengue was 100%.</p><p><strong>Conclusions: </strong>Primary dengue cases predominated, while severe dengue was associated with post-primary infection. The RDT proved to be a useful point-of-care tool for discriminating dengue immune status. DENV-3 and DENV-1 were the predominant serotypes driving recent transmission dynamics. The findings may help inform future vaccination strategies.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149135404","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":"Microbial profiles in pediatric complicated appendicitis: a systematic review and meta-analysis.","authors":"Rebecca F Almeida-Gomes, Rafaela B Massini, Juliana D Bronzato, Brenda P F A Gomes, Igor G O Garcia","doi":"10.1007/s10096-026-05662-7","DOIUrl":"https://doi.org/10.1007/s10096-026-05662-7","url":null,"abstract":"<p><strong>Purpose: </strong>Appendicitis, characterized by inflammation of the vermiform appendix, remains the leading cause of acute abdomen worldwide. Emerging evidence suggests that alterations in the intestinal microbiota may play a role in its pathogenesis. This study aimed to analyze the prevalence and microbiological profile of bacteria identified in pediatric patients with complicated acute appendicitis.</p><p><strong>Methods: </strong>A systematic review was conducted, including studies published up to April 2026 within a 12-year timeframe. Twenty-three observational cohort studies met the inclusion criteria and were included in the qualitative synthesis. Among these, studies reporting patient-level prevalence and using culture-based methods were included in the quantitative analysis.</p><p><strong>Results: </strong>The findings demonstrated that Escherichia coli was the most frequently identified microorganism in pediatric complicated appendicitis. Other commonly detected bacteria included Streptococcus spp., Bacteroides spp., Pseudomonas spp., Enterococcus spp., and Klebsiella spp. However, the certainty of the evidence for these findings remains low. Substantial methodological heterogeneity was observed across studies, particularly regarding sample collection, microbiological techniques, and outcome reporting, which limits the comparability and generalizability of the results.</p><p><strong>Conclusion: </strong>In conclusion, while Escherichia coli appears to predominate in pediatric complicated acute appendicitis, the available evidence is limited and should be interpreted with caution. Future well-designed multicenter studies using standardized protocols are essential to improve the consistency of findings and strengthen the overall evidence base.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149135395","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":"Global burden of varicella and herpes zoster in women of childbearing age: insights from the global burden of disease study 1990-2021.","authors":"Mingyue Wang, Xinghua Gao, Li Zhang","doi":"10.1007/s10096-026-05681-4","DOIUrl":"https://doi.org/10.1007/s10096-026-05681-4","url":null,"abstract":"<p><strong>Introduction: </strong>Although the epidemiological characteristics of varicella and herpes zoster have been systematically studied, there is currently a lack of research on the disease burden and changing trends in women of childbearing age (WCBA) (15-49 years) with varicella and herpes zoster.</p><p><strong>Methods: </strong>Based on data from the Global Burden of Disease (GBD) study, we investigated the prevalent cases, incident cases, and disability-adjusted life years (DALYs), prevalence rates, incidence rates, and DALY rates of varicella and herpes zoster among women of childbearing age across 204 countries and territories from 1990 to 2021. Temporal trends in disease burden were assessed by calculating the estimated annual percentage change (EAPC), which was calculated using a linear regression model, and the percentage changes from 1990 to 2021, calculated using 1990 as the reference year.</p><p><strong>Results: </strong>In 2021, the prevalent cases, incident cases, and DALYs of WCBA with varicella and herpes zoster increased globally by 53%, 55%, and 11%, respectively, compared with those in 1990. At the global level, the prevalent cases, incident cases, and DALYs reached 814,883.57, 5,274,247.6, and 79,698.78, respectively. The EAPCs for the prevalence rate, incidence rate, and DALY rate were 0.20 (95% CI: 0.17 to 0.24), 0.19 (95% CI: 0.15 to 0.23), and -0.89 (95% CI: -0.92 to -0.86), respectively. In most SDI regions, the prevalence rates and incidence rates increased, while the DALY rates decreased. The high-SDI region showed the highest in EAPCs for the prevalence rate, incidence rate, and DALY rate, with EAPCs of 0.61 (95% CI: 0.44 to 0.79), 0.67 (95% CI: 0.47 to 0.86), and 0.17 (95% CI: 0.04 to 0.30), respectively.</p><p><strong>Conclusion: </strong>Overall, from 1990 to 2021, the global burden of varicella and herpes zoster among WCBA increased, with increases in prevalent and incident cases as well as prevalence and incidence worldwide. Although the DALY rate declined in most SDI regions, it generally trended upward in the high-SDI region.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149105974","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":"Current laboratory diagnostics for tuberculosis: from conventional approaches to next-generation molecular and immunological technologies.","authors":"Ozgul Kisa","doi":"10.1007/s10096-026-05688-x","DOIUrl":"https://doi.org/10.1007/s10096-026-05688-x","url":null,"abstract":"<p><p>Tuberculosis (TB) remains a major global public health concern despite advances in diagnosis and treatment. Early and accurate diagnosis is essential for timely treatment initiation, interruption of transmission, and effective management of drug-resistant TB.Although microscopy and culture remain the cornerstones of TB diagnosis, their limited sensitivity and long turnaround times have driven the integration of molecular and immunological methods.This review summarizes current TB diagnostic approaches, including conventional methods, nucleic acid amplification tests (NAATs), line probe assay (LPA), next-generation sequencing (NGS), point-of-care systems, and interferon-gamma release assays (IGRAs).Emerging technologies, including host-response biomarkers, multi-omics approaches, artificial intelligence-based imaging, nanotechnology-based systems, and CRISPR/Cas-based diagnostics, are also discussed, with emphasis on their diagnostic performance, clinical applications, and current limitations.Current evidence indicates a shift from pathogen detection alone toward integrated approaches incorporating rapid molecular diagnosis, drug-resistance detection, host-response profiling, and immunological assessment.Future TB diagnostics are likely to increasingly rely on multimodal platforms combining molecular tools, host-response biomarkers, multi-omics data, and artificial intelligence to support more precise and clinically actionable TB management.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149105943","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":"Serum Borrelia IgG as a rule-out test in suspected lyme neuroborreliosis: a large retrospective cohort study.","authors":"Al-Hasan Hussein Dos, Anne-Mette Lebech, Jonas Bredtoft Boel, Lene Nielsen, Helene Mens, Masoud Moradi, Christian Stenør","doi":"10.1007/s10096-026-05679-y","DOIUrl":"https://doi.org/10.1007/s10096-026-05679-y","url":null,"abstract":"<p><strong>Objectives: </strong>In Europe, the diagnosis of Lyme neuroborreliosis (NB) relies on intrathecal Borrelia burgdorferi sensu lato (Bbsl) antibody production, but this test has limited sensitivity in early disease and requires lumbar puncture (LP). We therefore evaluated the diagnostic performance of the quantitative LIAISON^® serum Bbsl IgG assay across clinically relevant subgroups and its potential to guide LP decisions in patients with suspected NB.</p><p><strong>Methods: </strong>We retrospectively analyzed 3,841 patients who underwent intrathecal Bbsl antibody testing in the Capital Region of Denmark (2016-2024). NB cases were defined by European criteria and matched to non-NB controls. We assessed sensitivity, specificity, predictive values, area under the curve (AUC), and accuracy of Bbsl IgG across age groups, symptom durations, and clinical scenarios, and used logistic regression to model NB probability from serum IgG titers.</p><p><strong>Results: </strong>We included 392 NB patients and 2,681 non-NB controls, all with available serum Bbsl IgG LIAISON^® results. Overall sensitivity and specificity were both 88%. Accuracy was highest in children (0.90), while AUC peaked in patients with symptom duration > 4 weeks (0.96). Among patients with symptoms ≥ 2 weeks, sensitivity was 98% and negative predictive value 99%. For those with > 4 weeks symptom duration, both reached 100%. Predicted NB probability increased progressively with higher serum Bbsl titers.</p><p><strong>Interpretation: </strong>Taken together, our findings support a re-evaluation of the diagnostic sequence in suspected NB, although prospective external validation is required. A negative quantitative VlsE-based serum Bbsl IgG result after ≥ 2 weeks of symptoms was associated with a very low probability of NB in this selected cohort, supporting its potential use as a rule-out tool to guide LP decisions.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149105954","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":"Sex- and age-specific incidence and fraction of hospital contacts for infectious mononucleosis cases in Denmark in 1977-2011.","authors":"Klaus Rostgaard, Ragnar Kristjánsson, Kathrine Agergård Kaspersen, Christina Mikkelsen, Erik Sørensen, Bitten Aagaard, Mie Topholm Bruun, Sisse Rye Ostrowski, Henrik Ullum, Ole Birger Vesterager Pedersen, Christian Erikstrup, Henrik Hjalgrim","doi":"10.1007/s10096-026-05685-0","DOIUrl":"https://doi.org/10.1007/s10096-026-05685-0","url":null,"abstract":"<p><strong>Purpose: </strong>Infectious mononucleosis (IM) is a common presentation of primary Epstein-Barr virus (EBV) infection in adolescence and later, but rare in childhood. Occasionally, IM leads to a hospital contact with an IM diagnosis (hospIM). Knowing the sex-, age- and period- specific probability of IM leading to hospIM allows estimating the overall sex-, age- and period-specific incidence of IM from inverse probability weighting of hospIM occurrences.</p><p><strong>Methods: </strong>The probability of hospIM upon IM (hospfrac) was modelled in the Danish Blood Donor Study (DBDS) among persons with self-reported IM at age 0-29 years in 1977 to 2011. The probability of hospIM upon IM was modelled by sex-stratified generalized linear regression modelling of simple functions of age and calendar period with the aim of obtaining a simple, explicit, and transportable model for inverse probability weighting of hospIM occurrences.</p><p><strong>Results: </strong>Among 10,619 eligible IM cases, 937 (9%) had hospIM. Hospfrac peaked at around age 5 years with a nadir at age 12 years. No cohort trends in IM incidence were found.</p><p><strong>Conclusion: </strong>Absent IM cohort trends implied that childhood EBV sero-conversion patterns could be assumed stable from the 1960'ies. Previous detailed modelling of sex- and age-specific IM incidence for Denmark was extended and improved. Assumed incomplete recall of IM made the exact shape of hospfrac and IM incidence in childhood uncertain. IM and hospIM varied substantially by calendar period, likely reflecting both changing clinical practice and limited recall of events occurring more than 15 years earlier.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2026-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149105952","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":"Response to Letter to the Editor: \"Recurrence and mortality after Pseudomonas aeruginosa bloodstream infection\".","authors":"Felicity Edwards, Kevin B Laupland","doi":"10.1007/s10096-026-05549-7","DOIUrl":"10.1007/s10096-026-05549-7","url":null,"abstract":"","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":"3277"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148316405","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":"Performance evaluation of antimicrobial susceptibility testing methods for ceftazidime-avibactam and imipenem-relebactam against Klebsiella pneumoniae and Pseudomonas aeruginosa.","authors":"Xiaobo Xu, Erjie Lu, Lixin Wu","doi":"10.1007/s10096-026-05584-4","DOIUrl":"10.1007/s10096-026-05584-4","url":null,"abstract":"<p><strong>Background: </strong>Carbapenem-resistant Klebsiella pneumoniae (CR-KP) and Pseudomonas aeruginosa (CR-PA) present critical therapeutic challenges. Ceftazidime-avibactam (CAZ-AVI) and imipenem-relebactam (IMI-REL) are key treatment options, but optimal susceptibility testing methods and local resistance mechanisms need clarification.</p><p><strong>Methods: </strong>A total of 108 CR‑KP and 102 CR‑PA non‑duplicate clinical isolates (June 2025-February 2026) were tested. Susceptibility to CAZ‑AVI and IMI‑REL was determined by broth microdilution (BMD, reference method), gradient diffusion, and Kirby‑Bauer (K‑B) disk diffusion. Essential agreement (EA), categorical agreement (CA), and error rates were calculated. Carbapenemase types were detected by immunochromatography (CARBA5).</p><p><strong>Results: </strong>By BMD, CAZ-AVI susceptibility rates were 88.9% for CR-KP and 96.1% for CR-PA; IMI-REL susceptibility rates were 84.3% and 75.5%, respectively. For CAZ-AVI, gradient diffusion showed excellent CA with BMD (99.1% for CR-KP and 94.1% for CR-PA) and EA of 91.7% and 97.1%, respectively. In contrast, gradient diffusion for IMI-REL was suboptimal (CA 94.4% and EA 86.1% for CR-KP, and CA 84.3% and EA 87.3% for CR-PA). K-B disk diffusion performed poorly for IMI-REL (CA 75.0% for CR-KP and 77.5% for CR-PA; minor errors rates were 24.1% and 20.6%, respectively).</p><p><strong>Conclusion: </strong>CAZ-AVI and IMI-REL retain potent in vitro activity against contemporary CR-KP and CR-PA isolates. Gradient diffusion is a reliable alternative to BMD for ceftazidime-avibactam, whereas its accuracy is limited for imipenem-relebactam. K-B disk diffusion for IMI-REL is associated with unacceptably high error rates; reference method confirmation is recommended for isolates yielding non-susceptible results by this method.</p>","PeriodicalId":11782,"journal":{"name":"European Journal of Clinical Microbiology & Infectious Diseases","volume":" ","pages":"3159-3167"},"PeriodicalIF":3.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13676484/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148410961","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}