{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T23:57:59Z","timestamp":1790812679552,"version":"4.1.0"},"reference-count":30,"publisher":"American Society for Microbiology","issue":"5","license":[{"start":{"date-parts":[[2025,5,14]],"date-time":"2025-05-14T00:00:00Z","timestamp":1747180800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2025,5,14]],"date-time":"2025-05-14T00:00:00Z","timestamp":1747180800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["J Clin Microbiol"],"published-print":{"date-parts":[[2025,5,14]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title\/>\n                    <jats:p>\n                      Cefiderocol is a siderophore cephalosporin that utilizes iron transport systems to cross cell membranes. This unique strategy complicates antimicrobial susceptibility testing (AST) due to variable iron content in media. While guidance for using iron-depleted media exists for broth microdilution (BMD), disk diffusion (DD) with commercial media is a common AST method in the clinical laboratory. We investigated cefiderocol DD result variability using multiple Mueller\u2013Hinton agar (MHA) brands. DD results using Remel (Thermo Fisher Scientific, San Diego, CA), Hardy (Hardy Diagnostics, Springboro, OH), and BBL (Becton Dickinson, East Rutherford, NJ) MHA were compared to those of BMD using iron-depleted cation-adjusted Mueller\u2013Hinton broth. BMD reproducibility, BMD trailing endpoints, and DD intra- and inter-brand variability in zones of inhibition were investigated. Forty-seven multidrug-resistant clinical isolates and three Antibiotic Resistance Bank isolates composed of\n                      <jats:italic toggle=\"yes\">Pseudomonas aeruginosa<\/jats:italic>\n                      , carbapenemase (CP\u2013) and non-carbapenemase-producing (non-CP\u2013) carbapenem-resistant Enterobacterales (CRE),\n                      <jats:italic toggle=\"yes\">Acinetobacter baumannii<\/jats:italic>\n                      complex,\n                      <jats:italic toggle=\"yes\">Stenotrophomonas maltophilia<\/jats:italic>\n                      , and\n                      <jats:italic toggle=\"yes\">Burkholderia cepacia<\/jats:italic>\n                      complex were tested. Categorical agreement (CA) \u2265 90% was only demonstrated using CLSI breakpoints with BBL agar. Intra- and inter-brand variability in DD were highest for\n                      <jats:italic toggle=\"yes\">P. aeruginosa<\/jats:italic>\n                      and CRE, with 25% (5\/20) and 16.7% (3\/18) exhibiting discrepant AST interpretations, respectively. Isolates not susceptible to cefiderocol via BMD were commonly associated with AST interpretation errors and lower CA. Using commercial MHA for DD resulted in frequent AST interpretation discrepancies, particularly for isolates that were not susceptible to cefiderocol by BMD. Methods and quality control may need to be revisited to ensure the reliability of DD for cefiderocol AST.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>IMPORTANCE<\/jats:title>\n                    <jats:p>The novel mechanism of action of cefiderocol overcomes a variety of resistance mechanisms associated with gram-negative bacteria and positions the agent as an attractive option for treating infections involving multidrug-resistant pathogens. The availability of accurate, timely antimicrobial susceptibility testing methods for cefiderocol in clinical microbiology laboratories is critical as cefiderocol-resistant isolates have been described and may contribute to treatment failure. Iron-depleted broth microdilution testing may not be feasible for use in many clinical laboratories. While disk diffusion is an appealing, practical method to implement, our data demonstrate reproducibility issues across agar brands, most notably for organisms that do not test susceptible to cefiderocol when using broth microdilution. Discrepancy errors and misclassifications of resistant isolates as susceptible, and susceptible isolates as resistant, may mislead clinicians and compromise the treatment efficacy. More work is needed to standardize practical yet reproducible methods for cefiderocol antimicrobial susceptibility testing.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1128\/jcm.01648-24","type":"journal-article","created":{"date-parts":[[2025,3,25]],"date-time":"2025-03-25T11:11:57Z","timestamp":1742901117000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":8,"title":["Impact of media brand on cefiderocol disk diffusion results"],"prefix":"10.1128","volume":"63","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2658-6495","authenticated-orcid":true,"given":"M. G.","family":"DeMarco","sequence":"first","affiliation":[{"name":"Department of Pharmacy Services, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1268-1814","authenticated-orcid":true,"given":"A. M.","family":"Field","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Services, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L. E.","family":"Donohue","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Services, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H. L.","family":"Cox","sequence":"additional","affiliation":[{"name":"Department of Pharmacy Services, University of Virginia Health","place":["Charlottesville, USA"]},{"name":"Division of Infectious Diseases and International Health, School of Medicine, University of Virginia","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T. S.","family":"Kidd","sequence":"additional","affiliation":[{"name":"Clinical Microbiology, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K. E.","family":"Barry","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases and International Health, School of Medicine, University of Virginia","place":["Charlottesville, USA"]},{"name":"Clinical Microbiology, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3533-6351","authenticated-orcid":true,"given":"A. J.","family":"Mathers","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases and International Health, School of Medicine, University of Virginia","place":["Charlottesville, USA"]},{"name":"Clinical Microbiology, University of Virginia Health","place":["Charlottesville, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","unstructured":"Shionogi Inc. Fetroja (cefiderocol) [package insert]. 2021. U.S. Food and Drug Administration. Available from: https:\/\/www.accessdata.fda.gov\/drugsatfda_docs\/label\/2021\/209445s004lbl.pdf. Retrieved 20 May 2024."},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.01600-22"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmi.2022.04.013"},{"key":"e_1_3_3_5_2","series-title":"CLSI Supplement M100","volume-title":"Performance standards for antimicrobial susceptibility testing","author":"CLSI","year":"2024","unstructured":"CLSI. 2024. Performance standards for antimicrobial susceptibility testing. 34th ed. CLSI Supplement M100. Clinical and Laboratory Standards Institute.","edition":"34"},{"key":"e_1_3_3_6_2","series-title":"CLSI Standard M07","volume-title":"Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically","author":"CLSI","year":"2024","unstructured":"CLSI. 2024. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. 12th ed. CLSI Standard M07. Clinical and Laboratory Standards Institute.","edition":"12"},{"key":"e_1_3_3_7_2","volume-title":"The European Committee on Antimicrobial Susceptibility Testing","author":"EUCAST","year":"2024","unstructured":"EUCAST. 2024. Guidance document on broth microdilution testing of cefiderocol. The European Committee on Antimicrobial Susceptibility Testing."},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00951-20"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1574-6968.1988.tb02907.x"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1093\/jalm\/jfac131"},{"key":"e_1_3_3_11_2","volume-title":"The European Committee on Antimicrobial Susceptibility Testing","author":"EUCAST","year":"2024","unstructured":"EUCAST. 2024. Breakpoint tables for interpretation of MICs and zone diameters, version 14.0. The European Committee on Antimicrobial Susceptibility Testing."},{"key":"e_1_3_3_12_2","unstructured":"FDA identified breakpoints for cefiderocol injection. 2023. US Food & Drug Administration"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1186\/s13613-023-01146-5"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cmi.2022.11.005"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.03108-23"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(20)30796-9"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jgar.2021.10.014"},{"key":"e_1_3_3_18_2","series-title":"CLSI Standard M02","volume-title":"Performance standards for antimicrobial disk susceptibility tests","author":"CLSI","year":"2024","unstructured":"CLSI. 2024. Performance standards for antimicrobial disk susceptibility tests. 14th ed. CLSI Standard M02. Clinical and Laboratory Standards Institute.","edition":"14"},{"key":"e_1_3_3_19_2","series-title":"CLSI Guideline M52","volume-title":"Verification of commercial microbial identification and susceptibility test systems","author":"CLSI","year":"2015","unstructured":"CLSI. 2015. Verification of commercial microbial identification and susceptibility test systems. 1st ed. CLSI Guideline M52. Clinical and Laboratory Standards Institute, Wayne, PA.","edition":"1"},{"key":"e_1_3_3_20_2","series-title":"CLSI Guideline M23","volume-title":"Development of in vitro susceptibility test methods, breakpoints, and quality control parameters","author":"CLSI","year":"2023","unstructured":"CLSI. 2023. Development of in vitro susceptibility test methods, breakpoints, and quality control parameters. CLSI Guideline M23"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.01934-17"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.01649-20"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.05355-22"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms11081971"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkac080"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.3390\/antibiotics12030614"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.3390\/antibiotics12071212"},{"key":"e_1_3_3_28_2","unstructured":"EUCAST. 2024. EUCAST warnings concerning antimicrobial susceptibility testing products or procedures. Available from: https:\/\/www.eucast.org\/ast-of-bacteria\/warnings"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.01990-21"},{"key":"e_1_3_3_30_2","volume-title":"2019 AST agenda summary minutes","author":"Clinical and Laboratory Standards Institute","year":"2019","unstructured":"Clinical and Laboratory Standards Institute. 2019. 2019 AST agenda summary minutes. Clinical and Laboratory Standards Institute, Wayne, PA."},{"key":"e_1_3_3_31_2","volume-title":"The European Committee on Antimicrobial Susceptibility Testing","author":"EUCAST","year":"2024","unstructured":"EUCAST. 2024. EUCAST reading guide for broth microdilution, version 5.0. The European Committee on Antimicrobial Susceptibility Testing."}],"container-title":["Journal of Clinical Microbiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/jcm.01648-24","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/jcm.01648-24","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,5,14]],"date-time":"2025-05-14T09:01:45Z","timestamp":1747213305000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/jcm.01648-24"}},"subtitle":[],"editor":[{"given":"Patricia J.","family":"Simner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,5,14]]},"references-count":30,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2025,5,14]]}},"alternative-id":["10.1128\/jcm.01648-24"],"URL":"https:\/\/doi.org\/10.1128\/jcm.01648-24","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2024.10.17.618864","asserted-by":"object"}]},"ISSN":["0095-1137","1098-660X"],"issn-type":[{"value":"0095-1137","type":"print"},{"value":"1098-660X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,5,14]]},"assertion":[{"value":"2024-10-16","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-01-25","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-03-25","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e01648-24"}}