{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:51:06Z","timestamp":1760057466530,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2025,2,13]],"date-time":"2025-02-13T00:00:00Z","timestamp":1739404800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Project","award":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"],"award-info":[{"award-number":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"]}]},{"name":"CIBERINFEC","award":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"],"award-info":[{"award-number":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"]}]},{"name":"FCT-Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia, I.P.","award":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"],"award-info":[{"award-number":["101080889","CB21\/13\/00084","UIDB\/4255\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Ceftazidime\u2013avibactam (CZA) is a potent broad-spectrum drug combination covering extended-spectrum \u03b2-lactamases, AmpC, and carbapenemases of class A and D, OXA-48-type producers. Rapid antimicrobial susceptibility testing is crucial for the timely de-escalation\/escalation of therapy. We evaluate CZA susceptibility using the CE-IVD FASTgramneg kit (FASTinov\u00ae), a ground-breaking 2 h assay, based on flow cytometry technology for antimicrobial susceptibility testing. The assay involved rapid bacterial extraction and purification from positive blood cultures (PBCs), followed by a 1 h 37 \u00b0C incubation and flow cytometry analysis (Cytoflex, Beckman-Coulter). The susceptibility report was generated using a proprietary software and interpreted using EUCAST and CLSI 2024 criteria. Sensitivity and specificity were calculated against a reference standardized method (disk diffusion) according to ISO20776-2:2021. Overall, 135 Enterobacterales and 73 Pseudomonas aeruginosa isolates were studied. Thirty-four isolates were resistant to CZA, including six P. aeruginosa and 28 Enterobacterales (24 metallo-beta-lactamase producers, three KPC variants, and one co-producing KPC+NDM). Sensitivity and specificity reached 100% when using EUCAST and CLSI criteria compared with the reference method. The FASTinov ultra-rapid susceptibility assay for CZA demonstrated excellent results, potentially enabling de-escalation\/escalation even before the second dose. Combining the speed of a molecular assay with the comprehensive information of a phenotypic test offers valuable insights for treatment decisions.<\/jats:p>","DOI":"10.3390\/microorganisms13020414","type":"journal-article","created":{"date-parts":[[2025,2,13]],"date-time":"2025-02-13T10:36:58Z","timestamp":1739443018000},"page":"414","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Phenotypic Ultra-Rapid Antimicrobial Susceptibility Testing for Ceftazidime\u2013Avibactam: In Support of Antimicrobial Stewardship"],"prefix":"10.3390","volume":"13","author":[{"given":"In\u00eas","family":"Martins-Oliveira","sequence":"first","affiliation":[{"name":"FASTinov, S.A., 4200-135 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0693-597X","authenticated-orcid":false,"given":"Blanca","family":"P\u00e9rez-Viso","sequence":"additional","affiliation":[{"name":"Servicio de Microbiolog\u00eda, Hospital Universitario Ram\u00f3n y Cajal, Instituto Ram\u00f3n y Cajal de Investigaci\u00f3n Sanitaria (IRYCIS), 28034 Madrid, Spain"},{"name":"CIBER en Enfermedades Infecciosas, Instituto de Salud Carlos III, 28029 Madrid, Spain"}]},{"given":"Ros\u00e1rio","family":"Gomes","sequence":"additional","affiliation":[{"name":"FASTinov, S.A., 4200-135 Porto, Portugal"}]},{"given":"David","family":"Abreu","sequence":"additional","affiliation":[{"name":"FASTinov, S.A., 4200-135 Porto, Portugal"}]},{"given":"Ana","family":"Silva-Dias","sequence":"additional","affiliation":[{"name":"FASTinov, S.A., 4200-135 Porto, Portugal"},{"name":"RISE-Health Department of Pathology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1675-3173","authenticated-orcid":false,"given":"Rafael","family":"Cant\u00f3n","sequence":"additional","affiliation":[{"name":"Servicio de Microbiolog\u00eda, Hospital Universitario Ram\u00f3n y Cajal, Instituto Ram\u00f3n y Cajal de Investigaci\u00f3n Sanitaria (IRYCIS), 28034 Madrid, Spain"},{"name":"CIBER en Enfermedades Infecciosas, Instituto de Salud Carlos III, 28029 Madrid, Spain"}]},{"given":"Cid\u00e1lia","family":"Pina-Vaz","sequence":"additional","affiliation":[{"name":"FASTinov, S.A., 4200-135 Porto, Portugal"},{"name":"RISE-Health Department of Pathology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal"},{"name":"Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, 4099-002 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,13]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2022). Global Antimicrobial Resistance and Use Surveillance System (GLASS), World Health Organization."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"629","DOI":"10.1016\/S0140-6736(21)02724-0","article-title":"Global burden of bacterial antimicrobial resistance in 2019: A systematic analysis","volume":"399","author":"Murray","year":"2022","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Bassetti, M., Peghin, M., Vena, A., and Giacobbe, D.R. (2019). Treatment of Infections Due to MDR Gram-Negative Bacteria. Front. Med., 6.","DOI":"10.3389\/fmed.2019.00074"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"234","DOI":"10.1093\/cid\/ciw243","article-title":"Ceftazidime\/Avibactam and Ceftolozane\/Tazobactam: Second-generation \u03b2-Lactam\/\u03b2-Lactamase Inhibitor Combinations","volume":"63","author":"Bonomo","year":"2016","journal-title":"Clin. Infect. Dis."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Mendes, G., Ramalho, J.F., Bruschy-Fonseca, A., Lito, L., Duarte, A., Melo-Cristino, J., and Caneiras, C. (2022). First Description of Ceftazidime\/Avibactam Resistance in a ST13 KPC-70-Producing Klebsiella pneumoniae Strain from Portugal. Antibiotics, 11.","DOI":"10.3390\/antibiotics11020167"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Lim, T.P., Ho, J.Y., Teo, J.Q., Sim, J.H., Tan, S.H., Tan, T.T., and Kwa, A.L. (2023). In Vitro Susceptibility to Ceftazidime-Avibactam and Comparator Antimicrobial Agents of Carbapenem-Resistant Enterobacterales Isolates. Microorganisms, 11.","DOI":"10.3390\/microorganisms11092158"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Hern\u00e1ndez-Garc\u00eda, M., Castillo-Polo, J.A., Cordero, D.G., P\u00e9rez-Viso, B., Garc\u00eda-Castillo, M., Saez de la Fuente, J., Morosini, M.I., Cant\u00f3n, R., and Ruiz-Garbajosa, P. (2022). Impact of Ceftazidime-Avibactam Treatment in the Emergence of Novel KPC Variants in the ST307-Klebsiella pneumoniae High-Risk Clone and Consequences for Their Routine Detection. J. Clin. Microbiol., 60.","DOI":"10.1128\/jcm.02245-21"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Hobson, C.A., Pierrat, G., Tenaillon, O., Bonacorsi, S., Bercot, B., Jaouen, E., Jacquier, H., and Birgy, A. (2022). Klebsiella pneumoniae Carbapenemase Variants Resistant to Ceftazidime-Avibactam: An Evolutionary Overview. Antimicrob. Agents Chemother., 66.","DOI":"10.1128\/aac.00447-22"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6605","DOI":"10.1128\/AAC.01165-15","article-title":"First Report of Ceftazidime-Avibactam Resistance in a KPC-3-Expressing Klebsiella pneumoniae Isolate","volume":"59","author":"Humphries","year":"2015","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.jgar.2019.12.009","article-title":"Resistance to ceftazidime-avibactam and underlying mechanisms","volume":"22","author":"Wang","year":"2020","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Pina-Vaz, C., Silva-Dias, A., Martins-Oliveira, I., Gomes, R., Perez-Viso, B., Cruz, S., Rodrigues, A.G., Sarmento, A., and Cant\u00f3n, R. (2024). A multisite validation of a two hours antibiotic susceptibility flow cytometry assay directly from positive blood cultures. BMC Microbiol., 24.","DOI":"10.1186\/s12866-024-03341-1"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Iera, J., Seghieri, C., Tavoschi, L., Isonne, C., Baccolini, V., Petrone, D., Agodi, A., Barchitta, M., Arnoldo, L., and Creti, R. (2023). Early Warning Systems for Emerging Profiles of Antimicrobial Resistance in Italy: A National Survey. Int. J. Environ. Res. Public Health, 20.","DOI":"10.3390\/ijerph20095623"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1093\/cid\/cir323","article-title":"The challenges of antimicrobial drug resistance in Greece","volume":"53","author":"Miyakis","year":"2011","journal-title":"Clin. Infect. Dis."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1007\/s10096-023-04725-3","article-title":"An improved protocol for bacteria identification by MALDI-TOF MS directly from positive blood cultures","volume":"43","author":"Cruz","year":"2024","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_15","unstructured":"Institute CaLS (2024). M100 Performance Standards for Antimicrobial Susceptibility Testing, Institute CaLS. [32nd ed.]."},{"key":"ref_16","unstructured":"The European Committee on Antimicrobial Susceptibility Testing (2025, February 10). Breakpoint Tables for Interpretation of MICs and Zone Diameters, Version 14.0. Available online: http:\/\/www.eucast.org\/clinical_breakpoints\/."},{"key":"ref_17","unstructured":"(2021). Clinical Laboratory Testing and In Vitro Diagnostic Test Systems\u2014Susceptibility Testing of Infectious Agents and Evaluation of Performance of Antimicrobial Susceptibility Test Devices\u2014Part 2: Evaluation of Performance of Antimicrobial Susceptibility Test Devices against Reference Broth Micro-Dilution (Standard No. ISO 20776-2:2021). Available online: https:\/\/www.iso.org\/standard\/79377.html."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1016\/j.diagmicrobio.2010.12.002","article-title":"Multiplex PCR for detection of acquired carbapenemase genes","volume":"70","author":"Poirel","year":"2011","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"97","DOI":"10.2174\/1573396314666180308150908","article-title":"Ceftazidime\/Avibactam and Ceftolozane\/Tazobactam: Novel Therapy for Multidrug Resistant Gram Negative Infections in Children","volume":"14","author":"Rodriguez","year":"2018","journal-title":"Curr. Pediatr. Rev."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1093\/cid\/ciy492","article-title":"Efficacy of Ceftazidime-Avibactam Salvage Therapy in Patients With Infections Caused by Klebsiella pneumoniae Carbapenemase-producing K. pneumoniae","volume":"68","author":"Tumbarello","year":"2019","journal-title":"Clin. Infect. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"519","DOI":"10.1093\/cid\/ciy576","article-title":"Ceftazidime\/Avibactam, Meropenem\/Vaborbactam, or Both? Clinical and Formulary Considerations","volume":"68","author":"Pogue","year":"2019","journal-title":"Clin. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Shields, R.K., Chen, L., Cheng, S., Chavda, K.D., Press, E.G., Snyder, A., Pandey, R., Doi, Y., Kreiswirth, B.N., and Nguyen, M.H. (2017). Emergence of Ceftazidime-Avibactam Resistance Due to Plasmid-Borne bla(KPC-3) Mutations during Treatment of Carbapenem-Resistant Klebsiella pneumoniae Infections. Antimicrob. Agents Chemother., 61.","DOI":"10.1128\/AAC.02097-16"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"954","DOI":"10.1093\/cid\/ciw398","article-title":"High Rates of Nonsusceptibility to Ceftazidime-avibactam and Identification of New Delhi Metallo-\u03b2-lactamase Production in Enterobacteriaceae Bloodstream Infections at a Major Cancer Center","volume":"63","author":"Aitken","year":"2016","journal-title":"Clin. Infect. Dis."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"697","DOI":"10.1038\/nrmicro.2017.103","article-title":"Diagnosing antimicrobial resistance","volume":"15","author":"Burnham","year":"2017","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"635","DOI":"10.3855\/jidc.17096","article-title":"Evaluation of real-time PCR and flow cytometry efficiency in rapid detection of carbapenemase-producing Enterobacteriales","volume":"17","author":"Karsligil","year":"2023","journal-title":"J. Infect. Dev. Ctries."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Hattab, S., Ma, A.H., Tariq, Z., Vega Prado, I., Drobish, I., Lee, R., and Yee, R. (2024). Rapid Phenotypic and Genotypic Antimicrobial Susceptibility Testing Approaches for Use in the Clinical Laboratory. Antibiotics, 13.","DOI":"10.3390\/antibiotics13080786"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Liborio, M.P., Harris, P.N.A., Ravi, C., and Irwin, A.D. (2024). Getting Up to Speed: Rapid Pathogen and Antimicrobial Resistance Diagnostics in Sepsis. Microorganisms, 12.","DOI":"10.3390\/microorganisms12091824"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1559.e1","DOI":"10.1016\/j.cmi.2020.08.019","article-title":"Ultra-rapid flow cytometry assay for colistin MIC determination in Enterobacterales, Pseudomonas aeruginosa and Acinetobacter baumannii","volume":"26","author":"Fonseca","year":"2020","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Niu, S., Chavda, K.D., Wei, J., Zou, C., Marshall, S.H., Dhawan, P., Wang, D., Bonomo, R.A., Kreiswirth, B.N., and Chen, L. (2020). A Ceftazidime-Avibactam-Resistant and Carbapenem-Susceptible Klebsiella pneumoniae Strain Harboring bla(KPC-14) Isolated in New York City. mSphere, 5.","DOI":"10.1128\/msphere.00775-20"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Xiong, L., Wang, X., Wang, Y., Yu, W., Zhou, Y., Chi, X., Xiao, T., and Xiao, Y. (2022). Molecular mechanisms underlying bacterial resistance to ceftazidime\/avibactam. WIREs Mech. Dis., 14.","DOI":"10.1002\/wsbm.1571"}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/2\/414\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:33:10Z","timestamp":1760027590000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/13\/2\/414"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,13]]},"references-count":30,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,2]]}},"alternative-id":["microorganisms13020414"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms13020414","relation":{},"ISSN":["2076-2607"],"issn-type":[{"type":"electronic","value":"2076-2607"}],"subject":[],"published":{"date-parts":[[2025,2,13]]}}}