{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:36:55Z","timestamp":1785411415145,"version":"3.56.0"},"reference-count":12,"publisher":"American Society for Microbiology","issue":"4","license":[{"start":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T00:00:00Z","timestamp":1775520000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T00:00:00Z","timestamp":1775520000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/501100001711","name":"Schweizerischer Nationalfonds zur F\u00f6rderung der Wissenschaftlichen Forschung","doi-asserted-by":"publisher","award":["211422"],"award-info":[{"award-number":["211422"]}],"id":[{"id":"10.13039\/501100001711","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009396","name":"Universit\u00e4tsspital Z\u00fcrich","doi-asserted-by":"publisher","award":["USZF270808"],"award-info":[{"award-number":["USZF270808"]}],"id":[{"id":"10.13039\/501100009396","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Microbiol Spectr"],"published-print":{"date-parts":[[2026,4,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title\/>\n                    <jats:p>\n                      Vancomycin-resistant\n                      <jats:italic toggle=\"yes\">Enterococcus faecium<\/jats:italic>\n                      (VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      ) is a major cause of invasive healthcare-associated infections. Daptomycin is an important treatment option, but its efficacy may be compromised for isolates with minimum inhibitory concentrations (MICs) of 4\u20138 mg\/L, even at high doses. EUCAST has therefore assigned an \u201cinsufficient evidence\u201d category for\n                      <jats:italic toggle=\"yes\">Enterococcus<\/jats:italic>\n                      spp., making accurate MIC determination essential. We compared the performance of UMIC Daptomycin, several automated broth microdilution (BMD) systems, and E-test against the reference BMD method. Eighty-nine VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      isolates with borderline daptomycin susceptibility were tested by standard BMD in calcium-adjusted Mueller\u2013Hinton broth and by Phoenix, EUVENC, VITEK-2, UMIC Daptomycin, and E-test. CLSI breakpoints (susceptible-dose dependent \u2264 4 mg\/L,\n                      <jats:italic toggle=\"yes\">R<\/jats:italic>\n                      &gt; 4 mg\/L) were applied. Essential agreement (EA), categorical agreement (CA), bias, very major errors (vMEs), and major errors were assessed. Phoenix (EA = 92%, CA = 69%) and EUVENC (EA = 87.6%, CA = 74.2%) were the most accurate. UMIC achieved EA = 74.2% and CA = 70.8%. E-test (EA = 68.5%, CA = 66.3%) and VITEK-2 (EA = 67.4%, CA = 64%) showed lower accuracy. All methods displayed negative bias, underestimating MICs and frequently misclassifying isolates with MIC = 8 mg\/L, resulting in high vME rates. None of the methods met ISO-20776-2:2021 criteria. Automated BMD systems performed best, but all showed systematic MIC underestimation near the breakpoint. For reliable detection and confirmation of daptomycin resistance in VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      , BMD-based MIC methods\u2014manual or automated\u2014are recommended.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>IMPORTANCE<\/jats:title>\n                    <jats:p>\n                      Vancomycin-resistant\n                      <jats:italic toggle=\"yes\">Enterococcus faecium<\/jats:italic>\n                      (VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      ) is a major cause of hospital-acquired infections worldwide, posing a serious threat to patient safety and infection control. Daptomycin remains one of the few therapeutic options for severe VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      infections, yet its efficacy depends on accurately determining bacterial susceptibility. Even small variations in measured minimum inhibitory concentrations can influence treatment success or failure. In this study, we systematically evaluated several commercial antimicrobial susceptibility testing methods for daptomycin against VR\n                      <jats:italic toggle=\"yes\">Efm<\/jats:italic>\n                      and compared them with the reference broth microdilution (BMD) method. Our results show that many commonly used systems underestimate resistance, particularly for isolates near the clinical breakpoint. This underestimation may lead to inappropriate treatment decisions. The study provides evidence-based recommendations for clinical laboratories and emphasizes the importance of confirmatory BMD testing to ensure reliable results, optimize patient management, and prevent the further spread of antimicrobial resistance.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.1128\/spectrum.03590-25","type":"journal-article","created":{"date-parts":[[2026,3,5]],"date-time":"2026-03-05T14:44:57Z","timestamp":1772721897000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":0,"title":["Evaluation of commercial susceptibility testing methods for\n                    <i>in vitro<\/i>\n                    determining daptomycin susceptibility in vancomycin-resistant\n                    <i>Enterococcus faecium<\/i>"],"prefix":"10.1128","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4516-5952","authenticated-orcid":true,"given":"Stefano","family":"Mancini","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02crff812","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Medical Microbiology, University of Zurich","place":["Zurich, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"name":"NARA Network members","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0324-8437","authenticated-orcid":true,"given":"Dominique S.","family":"Blanc","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/019whta54","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Medical Microbiology, Lausanne University Hospital and University of Lausanne","place":["Lausanne, Switzerland"]},{"name":"Swiss National Reference Center for Emerging Antibiotic Resistance","place":["Fribourg, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9492-9088","authenticated-orcid":true,"given":"Silvio D.","family":"Brugger","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich","place":["Zurich, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9700-0474","authenticated-orcid":true,"given":"Sari","family":"Rasheed","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01jdpyv68","id-type":"ROR","asserted-by":"publisher"}],"name":"Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University","place":["Saarbr\u00fccken, Germany"]},{"name":"German Centre for Infection Research (DZIF), Partner Site Hannover","place":["Braunschweig, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Markus","family":"Jutzi","sequence":"additional","affiliation":[{"name":"Analytica Medizinische Laboratorien AG","place":["Zurich, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natalia","family":"Kolesnik-Goldmann","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02crff812","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Medical Microbiology, University of Zurich","place":["Zurich, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1042-5665","authenticated-orcid":true,"given":"Rolf","family":"Mueller","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01jdpyv68","id-type":"ROR","asserted-by":"publisher"}],"name":"Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Center for Infection Research (HZI), Saarland University","place":["Saarbr\u00fccken, Germany"]},{"name":"German Centre for Infection Research (DZIF), Partner Site Hannover","place":["Braunschweig, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3564-8603","authenticated-orcid":true,"given":"Adrian","family":"Egli","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02crff812","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Medical Microbiology, University of Zurich","place":["Zurich, Switzerland"]},{"name":"Swiss National Reference Center for Emerging Antibiotic Resistance","place":["Fribourg, Switzerland"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vladimira","family":"Hinic","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02crff812","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Medical Microbiology, University of Zurich","place":["Zurich, 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EUCAST disk diffusion method for antimicrobial susceptibility testing version 130. V\u00e4xj\u00f6 Sweden . https:\/\/www.eucast.org\/fileadmin\/src\/media\/PDFs\/EUCAST_files\/Disk_test_documents\/2025_manuals\/Manual_v_13.0_EUCAST_Disk_Test_2025.pdf."},{"key":"e_1_3_3_13_2","unstructured":"International Organization for Standard. 2007. Susceptibility testing of infectious agents and evaluation of performance of antimicrobial susceptibility test devices \u2014 Part 2: evaluation of performance of antimicrobial susceptibility test devices. Clinical Laboratory Testing and in Vitro Diagnostic Test Systems"}],"container-title":["Microbiology Spectrum"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.03590-25","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.03590-25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T13:10:34Z","timestamp":1775567434000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/spectrum.03590-25"}},"subtitle":[],"editor":[{"given":"Yunyu","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,4,7]]},"references-count":12,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2026,4,7]]}},"alternative-id":["10.1128\/spectrum.03590-25"],"URL":"https:\/\/doi.org\/10.1128\/spectrum.03590-25","relation":{},"ISSN":["2165-0497"],"issn-type":[{"value":"2165-0497","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,7]]},"assertion":[{"value":"2025-11-10","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-11-22","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-03-05","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e03590-25"}}