{"title":"Differential salivary disposition of linezolid and its two major metabolites (PNU-142300 and PNU-142586) after a single dose in healthy adults.","authors":"Yasuhiro Tsuji, Hitoshi Kawasuji, Tomona Yamada, Fumihiro Kurosaki, Naoki Oikawa, Makito Kaneda, Takahiko Aoyama, Taketo Uchiyama, Yoshihiro Yamamoto","doi":"10.1093/jac/dkag280","DOIUrl":"https://doi.org/10.1093/jac/dkag280","url":null,"abstract":"<p><strong>Background: </strong>Salivary therapeutic drug monitoring of linezolid has been proposed as a non-invasive alternative to blood sampling for pharmacokinetic assessment. However, the salivary disposition and pharmacokinetics of the two major linezolid metabolites, PNU-142300 and PNU-142586, have not been characterized.</p><p><strong>Objective: </strong>To evaluate the salivary disposition and serum protein binding of PNU-142300 and PNU-142586 using pharmacokinetic analysis.</p><p><strong>Methods: </strong>In this exploratory study, six healthy adult volunteers received a single intravenous dose of linezolid. Serial blood and saliva samples were collected for 10 h after dosing. The total and protein-unbound concentrations of linezolid and its two major metabolites, PNU-142300 and PNU-142586, were quantified using validated high-performance liquid chromatography methods.</p><p><strong>Results: </strong>Linezolid was consistently quantifiable in saliva, and its salivary concentration-time profile closely followed that of protein-unbound serum exposure. PNU-142300 and PNU-142586 were readily quantifiable in blood but remained below the lower limit of quantification in saliva in all participants at all sampling time points.</p><p><strong>Conclusions: </strong>Under the conditions studied, linezolid was quantifiable in saliva, whereas its two major metabolites were not, indicating different salivary disposition profiles for the parent drug and its metabolites. Salivary concentrations were consistent with protein-unbound serum exposure to linezolid under the conditions studied, whereas exposure to PNU-142300 and PNU-142586 could not be assessed using saliva and required blood-based measurements in the present study.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148706613","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}
Maria Vittoria Cossu, Anna Lisa Ridolfo, Antonio D'Avolio, Elisa Barnini, Andrea Gori, Dario Cattaneo, Cristina Gervasoni
{"title":"Differential pharmacokinetic decay of long-acting cabotegravir and rilpivirine after missed injections: a case series.","authors":"Maria Vittoria Cossu, Anna Lisa Ridolfo, Antonio D'Avolio, Elisa Barnini, Andrea Gori, Dario Cattaneo, Cristina Gervasoni","doi":"10.1093/jac/dkag277","DOIUrl":"https://doi.org/10.1093/jac/dkag277","url":null,"abstract":"","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148706659","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}
Mia Madeleine Lidén, Filippo Boroli, Elodie Von Dach, Pierre Lescuyer, David Tonoli, Angela Huttner
{"title":"Prospective evaluation of imipenem trough concentrations and clinical outcomes in critically ill patients.","authors":"Mia Madeleine Lidén, Filippo Boroli, Elodie Von Dach, Pierre Lescuyer, David Tonoli, Angela Huttner","doi":"10.1093/jac/dkag242","DOIUrl":"10.1093/jac/dkag242","url":null,"abstract":"<p><strong>Background: </strong>Imipenem is a broad-spectrum antibiotic commonly used in critically ill patients, whose pharmacokinetic profile can be highly variable. While imipenem therapeutic drug monitoring (TDM) is being adopted increasingly, efficacy and toxicity plasma thresholds remain incompletely defined. Few studies have prospectively and systematically assessed imipenem concentrations in severely ill patients before clinical failure or toxicity events occur.</p><p><strong>Methods: </strong>This prospective observational cohort study conducted at the University Hospitals of Geneva consecutively included all adult patients hospitalized for suspected or confirmed severe bacterial infections in the haematology, intermediate care and intensive care units whose clinicians prescribed imipenem. On inclusion, patients underwent imipenem plasma-concentration monitoring, with trough levels measured at steady state. We assessed the frequency of adverse events and clinical success over a 30-day period.</p><p><strong>Results: </strong>Of 142 patients undergoing imipenem monitoring, 106 had trough levels drawn at steady state. The median trough concentration was 2.4 mg/L (IQR 1.2-4.0). Among all patients, adverse events occurred in 4.9% (7/142), while clinical success was achieved in 88/106 with trough levels (83%). No significant differences in trough levels were observed between patients with and without clinical success or with and without adverse events. Renal clearance had a significant impact on trough levels.</p><p><strong>Conclusion: </strong>Prospective, universally applied imipenem monitoring reveals lower trough levels than previously described. Nonetheless, this cohort of critically ill and/or immunosuppressed patients still experienced high rates of clinical success, with few adverse events. While low trough concentrations did not predict failure, rare outlying higher concentrations (10-20 mg/L) also did not predict toxicity.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13482977/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793400","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}
Thang Hong Pham, Hanh Thi Hong Ngo, Tram Thi Phuong Pham, Nhung Thi Hong Le, Mai Thi Nguyen, Tuan Anh Nguyen, Huyen Thi Do, Duong Nhu Tran, Lan Trong Phan, Yoann Madec
{"title":"Performance of plasma separation cards for HIV drug-resistance genotyping in a resource-limited setting: comparison with plasma samples.","authors":"Thang Hong Pham, Hanh Thi Hong Ngo, Tram Thi Phuong Pham, Nhung Thi Hong Le, Mai Thi Nguyen, Tuan Anh Nguyen, Huyen Thi Do, Duong Nhu Tran, Lan Trong Phan, Yoann Madec","doi":"10.1093/jac/dkag279","DOIUrl":"https://doi.org/10.1093/jac/dkag279","url":null,"abstract":"<p><strong>Background: </strong>HIV drug resistance (HIVDR) threatens the effectiveness of antiretroviral therapy (ART) programmes in low- and middle-income countries. The Cobas Plasma Separation Card (PSC) is a recently developed specimen collection tool with potential to expand access to HIVDR genotyping in remote settings. This study evaluates PSC performance for HIVDR genotyping compared with plasma.</p><p><strong>Methods: </strong>Paired plasma and PSC specimens were selected from 250 people living with HIV (PLHIV) on ART ≥6 months with viral load (VL) ≥1000 copies/mL. HIVDR genotyping followed CDC Atlanta in-house protocol; resistance interpretation used the Stanford HIVdb algorithm. Paired sequences were compared for subtype, nucleotide similarity, mutation profile and drug-resistance classification.</p><p><strong>Results: </strong>Twenty paired specimens met inclusion criteria. Amplification of the HIV-1 Pol gene succeeded in 19/20 (95%) PSC samples. Of 19 paired sequences, nucleotide similarity was 98.5% (IQR 98.0%-99.3%). Eleven plasma samples showed 37 major drug-resistance mutations (MDM); 35 (94.6%) concordant MDM were identified in PSC. Discordances in four pairs were limited to mixed versus single bases and did not alter drug-resistance classification. Only one pair showed a clinically significant discordance (K103N detected in plasma but not initially in PSC).</p><p><strong>Conclusions: </strong>PSC demonstrated good concordance with plasma for HIVDR genotyping and has potential as an alternative specimen type for clinical practice and surveillance in resource-limited settings.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13487323/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793370","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":"Pulmonary pharmacokinetics, epithelial lining fluid exposure and PK/PD characterization of the novel pleuromutilin derivative APTM against methicillin-resistant Staphylococcus aureus and Streptococcus pneumoniae in mice.","authors":"Weicong Yang, Luoju Wang, Lei Yan, Haibo Wang, Xiaona Ma, Taiming Lv, Huanzhong Ding","doi":"10.1093/jac/dkag306","DOIUrl":"10.1093/jac/dkag306","url":null,"abstract":"<p><strong>Objectives: </strong>To characterize pulmonary pharmacokinetics (PK), epithelial lining fluid (ELF) exposure, antibacterial activity and preliminary PK/pharmacodynamic (PK/PD) relationships of the pleuromutilin derivative APTM in neutropenic murine lung infection models.</p><p><strong>Methods: </strong>Plasma PK and ELF exposure were assessed after a single oral dose in healthy mice. Minimum inhibitory concentrations (MICs) and in vitro time-kill activity were determined against methicillin-resistant Staphylococcus aureus USA300 and Streptococcus pneumoniae ATCC 49619. In vivo efficacy was assessed in neutropenic murine lung infection models. The ratio of the 24 h area under the plasma concentration-time curve to MIC (AUC0-24h/MIC) and the ratio of maximum plasma concentration to MIC (Cmax/MIC) were evaluated as candidate indices using Sigmoid Imax models.</p><p><strong>Results: </strong>Plasma exposure increased approximately linearly over 10-150 mg/kg. Mean total ELF/plasma ratios were 1.21 for Cmax and 2.05 for the area under the concentration-time curve from time zero to infinity (AUC0-∞). MICs were 0.25 mg/L for USA300 and 0.5 mg/L for ATCC 49619. Relative to the 2 h baseline, maximal mean reductions in pulmonary bacterial burden at 150 mg/kg were 3.39 log10 cfu/mL for USA300 and 1.63 log10 cfu/mL for ATCC 49619. Under the single every-12-h (q12h) regimen, AUC0-24h/MIC showed a stronger association with antibacterial efficacy than Cmax/MIC.</p><p><strong>Conclusions: </strong>APTM achieved measurable pulmonary exposure and antibacterial activity in murine lung infection models. AUC0-24h/MIC was the best-performing exposure metric among those evaluated under the present conditions; it should not be interpreted as a definitive PK/PD driver. These exploratory, isolate-specific findings support further PK/PD studies of APTM for respiratory infections.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148860295","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}
Céline Dupieux, Patricia Martins Simoes, Benjamin Youenou, François Vandenesch, Anne Tristan, Frédéric Laurent
{"title":"A fluorogenic biotracer for reliable detection of staphylococcal beta-lactamase: towards improved precision therapy in severe MSSA infections.","authors":"Céline Dupieux, Patricia Martins Simoes, Benjamin Youenou, François Vandenesch, Anne Tristan, Frédéric Laurent","doi":"10.1093/jac/dkag268","DOIUrl":"https://doi.org/10.1093/jac/dkag268","url":null,"abstract":"<p><strong>Background and objectives: </strong>Accurate detection of staphylococcal beta-lactamase remains a diagnostic challenge, despite its importance for guiding antibiotic therapy, particularly in severe infections, such as endocarditis and bacteraemia. Currently, no available method reliably detects beta-lactamase activity in all staphylococcal species. Here, we evaluated a novel fluorogenic biotracer, 352600-C (MOLSID, Lyon, France), designed to detect beta-lactamase activity in staphylococci.</p><p><strong>Methods: </strong>The 352600-C biotracer was incorporated into Mueller-Hinton agar plates onto which staphylococcal strains were subcultured at 37°C. Colony fluorescence was assessed at 4, 6 and 24 h using a 365 nm UV lamp. The assay was performed on a large collection of blaZ-positive (n = 124, including BlaZ types A, B, C and D) and blaZ-negative (n = 69) staphylococci from 18 species (Staphylococcus aureus, n = 100; S. non-aureus, n = 93). Molecular detection of the blaZ gene using WGS served as the gold standard. Phenotypic susceptibility to penicillins was also tested using EUCAST recommendations.</p><p><strong>Results: </strong>After 4, 6 and 24 h of incubation, the assay showed sensitivities of 92.2%, 96.9% and 100% for S. aureus and 50.0%, 88.3% and 100% for non-aureus staphylococci, respectively. None of the 69 blaZ-negative strains produced fluorescent colonies (specificity 100%). Notably, the assay detected all BlaZ types. Penicillin disc diffusion showed 98.4% sensitivity and 77.8% specificity for MSSA.</p><p><strong>Conclusions: </strong>This novel assay for the detection of staphylococcal beta-lactamase demonstrated simplicity, rapidity and excellent accuracy after 24 h incubation (100% sensitivity and specificity) across a genetically diverse and representative collection of clinical isolates, making it a valuable tool for routine diagnostics and antimicrobial stewardship.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13475114/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148761681","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}
Alexandra Serris, François Danion, Joseph Benzakoun, Pierre Tattevin, Jean-Pierre Gangneux, Renaud Verdon, Julie Bonhomme, Lucie Lelièvre, Yacine Tandjaoui-Lambiotte, Thorsten Braun, Jean-Philippe Talarmin, Guillaume Desoubeaux, Claire Aguilar, Olivier Lortholary, David Ghez, Fanny Lanternier
{"title":"Cerebral aspergillosis under ibrutinib therapy: clinical features and management challenges.","authors":"Alexandra Serris, François Danion, Joseph Benzakoun, Pierre Tattevin, Jean-Pierre Gangneux, Renaud Verdon, Julie Bonhomme, Lucie Lelièvre, Yacine Tandjaoui-Lambiotte, Thorsten Braun, Jean-Philippe Talarmin, Guillaume Desoubeaux, Claire Aguilar, Olivier Lortholary, David Ghez, Fanny Lanternier","doi":"10.1093/jac/dkag266","DOIUrl":"10.1093/jac/dkag266","url":null,"abstract":"<p><strong>Background: </strong>Ibrutinib is a recognized risk factor for invasive fungal disease (IFD) recognized in the 2019 revised criteria of the European Organisation for Research and Treatment of Cancer. Cerebral aspergillosis (CA) under ibrutinib has been relatively frequently reported, but its particular characteristics remain insufficiently described.</p><p><strong>Methods: </strong>The CEREALS study was a nationwide retrospective cohort of 119 patients diagnosed with CA between 2006 and 2018. We analysed 10 patients who developed CA following ibrutinib therapy and compared their clinical, radiological and outcome data with those of other patients with haematological malignancies from this cohort.</p><p><strong>Results: </strong>Nine patients received ibrutinib for chronic lymphocytic leukaemia and one for diffuse large B-cell lymphoma after a median of two prior treatment lines. None received anti-mould prophylaxis, although 80% of them presented additional IFD risk factors. CA occurred a median of 2.9 months after ibrutinib initiation. All cases resulted from haematogenous dissemination, with extracerebral involvement in 70% of the patients, mostly the lungs. Brain imaging revealed supratentorial abscesses without meningeal involvement in all patients, typically manifesting with focal neurological deficits. Serum galactomannan was positive in 33% of tested patients, exclusively in neutropenic individuals. Six-week mortality was 40%. Compared with other haematological malignancy patients in the CEREALS cohort, ibrutinib-associated CA showed exclusive haematogenous spread, infrequent serum galactomannan positivity and lower mortality (40% versus 62%).</p><p><strong>Conclusions: </strong>Cerebral aspergillosis during ibrutinib therapy shows particular features. An invasive microbiological workup is often required, as serum galactomannan appears to have limited sensitivity in this context.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148669439","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}
Bram Spruijtenburg, Carolina Melchior Do Prado, Mariana Rodrigues Trápaga, Dallas J Smith, Philippe J Dufresne, Jacques F Meis, Larissa Fernandes, Maria Sueli Felipe, Daniel R Matute, Theun De Groot, Amanda Ribeiro Dos Santos, Regielly Caroline Raimundo Cognialli, Nathan P Wiederhold, Vânia A Vicente, Flavio de Queiroz-Telles, Melissa Orzechowski Xavier, Marcus de Melo Teixeira, Eelco F J Meijer
{"title":"Towards standardized antifungal susceptibility testing for Sporothrix brasiliensis.","authors":"Bram Spruijtenburg, Carolina Melchior Do Prado, Mariana Rodrigues Trápaga, Dallas J Smith, Philippe J Dufresne, Jacques F Meis, Larissa Fernandes, Maria Sueli Felipe, Daniel R Matute, Theun De Groot, Amanda Ribeiro Dos Santos, Regielly Caroline Raimundo Cognialli, Nathan P Wiederhold, Vânia A Vicente, Flavio de Queiroz-Telles, Melissa Orzechowski Xavier, Marcus de Melo Teixeira, Eelco F J Meijer","doi":"10.1093/jac/dkag286","DOIUrl":"10.1093/jac/dkag286","url":null,"abstract":"<p><p>Sporotrichosis caused by Sporothrix brasiliensis is increasingly reported in South America. Infections in humans are mostly due to zoonotic transmission by cats. For both hosts, itraconazole is the drug of choice despite long treatment duration. Resistance surveillance is warranted, but protocols for antifungal susceptibility testing (AFST) are not always harmonized between laboratories largely due to Sporothrix species being thermally dimorphic and the absence of well-defined consensus methodologies to address how to deal with yeast/mould phases. To standardize susceptibility testing methodology, we propose to modify the current Clinical Laboratory and Standards Institute (CLSI) M38 broth microdilution methodology with S. brasiliensis culture for 7 days at 30°C (rather than 35°C) on potato dextrose agar (PDA), followed by microscopic confirmation of pure mycelial phase. Incubation temperature would also be modified to 30°C for 72 hours. By following this standardized method for at least itraconazole, terbinafine and amphotericin B, S. brasiliensis non-wild-type isolates and correlations with clinical outcomes can be properly investigated. The proposed method is a consensus-oriented interim approach rather than a fully validated standard.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13487325/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148793339","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}
Roy Dinata, Piyush Baindara, Sourav Chakraborty, Safikureshi Mondal, Santi M Mandal
{"title":"Mutation-driven alterations in the AcrB efflux pump modulate antibiotic resistance in Klebsiella pneumoniae.","authors":"Roy Dinata, Piyush Baindara, Sourav Chakraborty, Safikureshi Mondal, Santi M Mandal","doi":"10.1093/jac/dkag270","DOIUrl":"https://doi.org/10.1093/jac/dkag270","url":null,"abstract":"<p><strong>Objectives: </strong>To investigate the global prevalence of the acrB efflux transporter among antibiotic resistance genes (ARGs) in Klebsiella pneumoniae and to determine how mutations within AcrB drug-binding pockets influence structural stability and antibiotic interactions.</p><p><strong>Methods: </strong>A global genomic analysis of 42 ARGs reported in K. pneumoniae isolates worldwide was performed to identify the prominence of acrB. A total of 92 AcrB protein sequences were assessed for drug-binding pocket mutations relative to the wild-type strain NCTC9637. De novo protein structures were generated using AlphaFold2 and evaluated through molecular dynamics (MD) simulations. MD analyses were conducted with multiple antibiotics to assess the impact of pocket mutations on drug-binding affinities.</p><p><strong>Results: </strong>acrB emerged as the most widely distributed ARG, conferring resistance to at least 12 antibiotic classes. Three isolates, NCTC9617, NCTC9645, and NCTC13635, displayed multiple drug-binding pocket mutations when compared with the wild type. MD simulations revealed marked structural instability in NCTC9645, while NCTC13635 showed convergence towards a wild-type-like conformation. Docking analyses demonstrated that binding pocket mutations altered antibiotic-binding affinities, suggesting possible alterations in substrate recognition and transport.</p><p><strong>Conclusions: </strong>AcrB is a key driver of multidrug resistance in K. pneumoniae, and mutations within its drug-binding pockets can significantly impact protein stability and antibiotic-binding behaviour. Monitoring these structural variations may help predict emerging resistance patterns and guide therapeutic decision-making.</p><p><strong>Importance: </strong>Multidrug-resistant Klebsiella pneumoniae infections are a growing clinical threat with limited therapeutic options. By integrating global resistance gene surveillance with structural modelling of AcrB efflux pump variants, this study identifies drug-binding pocket mutations that modulate antibiotic affinity and efflux pump stability. These insights provide a molecular basis for predicting treatment failure, guiding precision antibiotic therapy, and advancing the development of efflux pump inhibitors as adjunctive treatments for drug-resistant Gram-negative infections.</p>","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148673835","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}
Antoine Portais, Stéphane Lastere, David Boutolleau
{"title":"Treatment of acyclovir-resistant varicella-zoster virus keratitis with amenamevir in an immunocompromised patient.","authors":"Antoine Portais, Stéphane Lastere, David Boutolleau","doi":"10.1093/jac/dkag275","DOIUrl":"https://doi.org/10.1093/jac/dkag275","url":null,"abstract":"","PeriodicalId":14969,"journal":{"name":"Journal of Antimicrobial Chemotherapy","volume":"81 9","pages":""},"PeriodicalIF":4.1,"publicationDate":"2026-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148678368","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}