{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T17:12:01Z","timestamp":1787505121138,"version":"build-2736575974"},"reference-count":13,"publisher":"Oxford University Press (OUP)","issue":"12","license":[{"start":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T00:00:00Z","timestamp":1758844800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["226007\/Z\/22\/Z"],"award-info":[{"award-number":["226007\/Z\/22\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000002","name":"National Institutes of Health","doi-asserted-by":"publisher","award":["1R01AI146338"],"award-info":[{"award-number":["1R01AI146338"]}],"id":[{"id":"10.13039\/100000002","id-type":"DOI","asserted-by":"publisher"}]},{"name":"GOSH\/ICH Biomedical Research Centre"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,12,2]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Aztreonam\/avibactam is a novel \u03b2-lactam\/\u03b2-lactamase inhibitor (BL\/BLI) combination active against carbapenem-resistant Enterobacterales (CRE), including MBL-producing isolates. In May 2024, EUCAST published Enterobacterales breakpoints for aztreonam\/avibactam. This study aimed to assess the performance of commercially available disc diffusion (DD) against broth microdilution (BMD) using the latest EUCAST breakpoints.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We tested 278 CRE causing infections in 17 Greek ICUs between 2021 and 2023, using 30\/20 \u03bcg aztreonam\/avibactam discs and BMD according to EUCAST methodology and EUCAST version 15.0 breakpoints.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Most isolates were identified as Klebsiella pneumoniae (97.8%), and 98.9% produced carbapenemases, including 46.4% KPC, 20.1% NDM, 5.4% VIM and 27% multiple carbapenemases. Using BMD, 94.2% of isolates were susceptible to aztreonam\/avibactam. Conversely, using DD, 66.9% were susceptible, 33.1% resistant and 27% within the area of technical uncertainty (ATU). Most isolates in the ATU were KPC-producing (68%) or KPC and MBL-producing (29.3%). All isolates in the ATU (22\u201324 mm) tested susceptible by BMD (MIC \u2264 4 mg\/L). One isolate exhibited resistance by DD (20 mm), but was susceptible by BMD. Categorical agreement (CA) was 72.7%, with 29% major errors (MEs) and 0% very major errors (VMEs). Using a breakpoint of 22 mm, CA, ME and VME were 99.6%, 0.4% and 0%, respectively.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Aztreonam\/avibactam showed potent in vitro activity against MBL- and KPC-producing Enterobacterales. Using the 2025 EUCAST breakpoint, all isolates in the ATU tested susceptible by BMD, leading to high MEs of the DD method. A 22\u202fmm breakpoint would have corrected this discrepancy in our cohort.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/jac\/dkaf361","type":"journal-article","created":{"date-parts":[[2025,9,9]],"date-time":"2025-09-09T11:37:28Z","timestamp":1757417848000},"page":"3273-3277","source":"Crossref","is-referenced-by-count":4,"title":["Comparative evaluation of disc diffusion and broth microdilution methods for aztreonam\/avibactam susceptibility testing in Enterobacterales"],"prefix":"10.1093","volume":"80","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8008-4835","authenticated-orcid":false,"given":"Ioannis","family":"Baltas","sequence":"first","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Deny","family":"Tsakri","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sofia","family":"Vourli","sequence":"additional","affiliation":[{"name":"Institute of Biosciences and Applications, NCSR \u2018Demokritos\u2019 , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Himani","family":"Solanki","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Evelyn","family":"Murrell","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eftychia","family":"Kiousi","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zacharias","family":"Tsakris","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriella","family":"Kuczmar","sequence":"additional","affiliation":[{"name":"Department of Clinical Microbiology, Great Ormond Street Hospital for Children , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nikoletta","family":"Smyrni","sequence":"additional","affiliation":[{"name":"Pfizer Hellas , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ioannis","family":"Skiadas","sequence":"additional","affiliation":[{"name":"Pfizer Hellas , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vassilios","family":"Grammelis","sequence":"additional","affiliation":[{"name":"Pfizer Hellas , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2417-346X","authenticated-orcid":false,"given":"James","family":"Hatcher","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]},{"name":"Department of Clinical Microbiology, Great Ormond Street Hospital for Children , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Damianos","family":"Menegas","sequence":"additional","affiliation":[{"name":"Pfizer Hellas , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Athanasios","family":"Tsakris","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Medical School, National and Kapodistrian University of Athens , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Georgia","family":"Vrioni","sequence":"additional","affiliation":[{"name":"Department of Microbiology, Medical School, National and Kapodistrian University of Athens , Athens ,","place":["Greece"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Louis","family":"Grandjean","sequence":"additional","affiliation":[{"name":"Infection, Immunity & Inflammation Department, UCL Institute of Child Health , London ,","place":["UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2025,9,26]]},"reference":[{"key":"2025120206221934500_dkaf361-B1","doi-asserted-by":"publisher","first-page":"1871","DOI":"10.1093\/cid\/ciaa586","article-title":"Efficacy of ceftazidime\u2013avibactam plus aztreonam in patients with bloodstream infections caused by metallo-\u03b2-lactamase\u2013producing Enterobacterales","volume":"72","author":"Falcone","year":"2021","journal-title":"Clin Infect Dis"},{"key":"2025120206221934500_dkaf361-B2","doi-asserted-by":"publisher","first-page":"285","DOI":"10.3390\/antibiotics13030285","article-title":"Antimicrobial and diagnostic stewardship of the novel \u03b2-lactam\/\u03b2-lactamase inhibitors for infections due to carbapenem-resistant Enterobacterales species and Pseudomonas aeruginosa","volume":"13","author":"Ferous","year":"2024","journal-title":"Antibiotics"},{"key":"2025120206221934500_dkaf361-B3","doi-asserted-by":"publisher","first-page":"59","DOI":"10.1093\/jac\/dkae367","article-title":"Resistance profiles of carbapenemase-producing Enterobacterales in a large centre in England: are we already losing cefiderocol?","volume":"80","author":"Baltas","year":"2025","journal-title":"J Antimicrob Chemother"},{"key":"2025120206221934500_dkaf361-B4","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/s12879-024-10133-5","article-title":"Antimicrobial susceptibility of Enterobacterales causing bloodstream infection in United States medical centres: comparison of aztreonam\/avibactam with beta-lactams active against carbapenem-resistant Enterobacterales","volume":"24","author":"Sader","year":"2024","journal-title":"BMC Infect Dis"},{"key":"2025120206221934500_dkaf361-B5","doi-asserted-by":"publisher","first-page":"927","DOI":"10.1002\/phar.4629","article-title":"Aztreonam\u2013avibactam: the dynamic duo against multidrug-resistant gram-negative pathogens","volume":"44","author":"Al Musawa","year":"2024","journal-title":"Pharmacother J Hum Pharmacol Drug Ther"},{"key":"2025120206221934500_dkaf361-B6","doi-asserted-by":"publisher","first-page":"106776","DOI":"10.1016\/j.ijantimicag.2023.106776","article-title":"Activity of aztreonam\/avibactam against metallo-\u03b2-lactamase-producing Enterobacterales from the UK: impact of penicillin-binding protein-3 inserts and CMY-42 \u03b2-lactamase in Escherichia coli","volume":"61","author":"Livermore","year":"2023","journal-title":"Int J Antimicrob Agents"},{"key":"2025120206221934500_dkaf361-B7","author":"EUCAST"},{"key":"2025120206221934500_dkaf361-B8","doi-asserted-by":"publisher","first-page":"e00649-24","DOI":"10.1128\/jcm.00649-24","article-title":"Evaluation of gradient strip diffusion for susceptibility testing of aztreonam\u2013avibactam in metallo-\u03b2-lactamase-producing Enterobacterales","volume":"62","author":"Lemon","year":"2024","journal-title":"J Clin Microbiol"},{"key":"2025120206221934500_dkaf361-B9","author":"Baltas"},{"key":"2025120206221934500_dkaf361-B10","doi-asserted-by":"publisher","first-page":"e00799-23","DOI":"10.1128\/jcm.00799-23","article-title":"Antimicrobial Resistance Laboratory Network\u2019s multisite evaluation of the ThermoFisher Sensititre GN7F broth microdilution panel for antimicrobial susceptibility testing","volume":"61","author":"Bhatnagar","year":"2023","journal-title":"J Clin Microbiol"},{"key":"2025120206221934500_dkaf361-B11","doi-asserted-by":"publisher","first-page":"e01934-17","DOI":"10.1128\/JCM.01934-17","article-title":"CLSI methods development and standardization working group best practices for evaluation of antimicrobial susceptibility tests","volume":"56","author":"Humphries","year":"2018","journal-title":"J Clin Microbiol"},{"key":"2025120206221934500_dkaf361-B12","author":"Daikos"},{"key":"2025120206221934500_dkaf361-B13","doi-asserted-by":"publisher","first-page":"1309","DOI":"10.1093\/jac\/dkae097","article-title":"Performance of disk diffusion method for aztreonam in combination with avibactam against Enterobacterales","volume":"79","author":"Yin","year":"2024","journal-title":"J Antimicrob Chemother"}],"container-title":["Journal of Antimicrobial Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/jac\/article-pdf\/80\/12\/3273\/64399530\/dkaf361.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/jac\/article-pdf\/80\/12\/3273\/64399530\/dkaf361.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,2]],"date-time":"2025-12-02T11:22:25Z","timestamp":1764674545000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/jac\/article\/80\/12\/3273\/8264414"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,26]]},"references-count":13,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2025,9,26]]},"published-print":{"date-parts":[[2025,12,2]]}},"URL":"https:\/\/doi.org\/10.1093\/jac\/dkaf361","relation":{},"ISSN":["0305-7453","1460-2091"],"issn-type":[{"value":"0305-7453","type":"print"},{"value":"1460-2091","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2025,12]]},"published":{"date-parts":[[2025,9,26]]}}}