{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T14:24:14Z","timestamp":1787149454164,"version":"build-2736575974"},"reference-count":38,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T00:00:00Z","timestamp":1787097600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Clin. Med.","JCM"],"abstract":"<jats:p>Background\/Objectives: The rise of extended-spectrum \u03b2-lactamase (ESBL)-producing Enterobacterales has led to an increased carbapenem use, raising concerns regarding selection pressure for carbapenem-resistant organisms. Ceftolozane\u2013tazobactam (C\/T) is a potential effective carbapenem-sparing alternative. This single-centre retrospective study evaluated the clinical effectiveness and mortality predictors of ceftolozane\u2013tazobactam versus meropenem as definitive targeted therapy for ESBL-producing Enterobacterales bloodstream infections (BSIs). Methods: We conducted a single-center retrospective analysis of adult hospitalized patients between January 2022 and February 2024 who presented with BSIs caused by ESBL-producing Enterobacterales. Patients (N = 185) were included if they received either C\/T (n = 73) or optimized high-dose meropenem (n = 112) for at least 48 h. The primary clinical endpoint was all-cause 30-day mortality. Secondary endpoints included clinical success (cure), in-hospital mortality, treatment duration, microbiological eradication, and infection recurrence rates. A multivariable logistic regression model was executed to determine independent predictors of 30-day mortality. Results: Escherichia coli (54.1%) and Klebsiella pneumoniae (35.1%) were the primary pathogens. The raw clinical success rate was higher with C\/T than meropenem (83.6% vs. 71.6%, p = 0.078). Unadjusted 30-day mortality was 12.3% for C\/T and 19.6% for meropenem (p = 0.342). Zero recurrences occurred with C\/T compared to an 8.0% recurrence rate with meropenem (0\/73 [0.0%] in C\/T vs. 9\/112 [8.0%] in meropenem, p = 0.015). In the multivariable logistic regression analysis, definitive targeted treatment with C\/T was independently associated with lower odds of all-cause 30-day mortality (Adjusted Odds Ratio [aOR] 0.60; 95% Confidence Interval [CI] 0.33\u20130.92; p = 0.022). Conversely, independent clinical mortality risks included male gender (p = 0.027), baseline SOFA score (p = 0.001), septic shock (p = 0.001), and an unknown primary infection source (p = 0.001). Conclusions: In this single-center retrospective observational cohort, definitive targeted therapy with ceftolozane\u2013tazobactam was associated with favorable clinical success and lower adjusted 30-day mortality compared to meropenem in patients with ESBL Enterobacterales BSIs. These observational data support further prospective evaluation of C\/T as a potential carbapenem-sparing option. Prospective randomized controlled trials are required to confirm these findings before clinical practice algorithms are modified.<\/jats:p>","DOI":"10.3390\/jcm15166414","type":"journal-article","created":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T13:14:01Z","timestamp":1787145241000},"page":"6414","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparison of Ceftolozane\u2013Tazobactam Versus Meropenem Regimens in Treating Bloodstream Infections Caused by Extended-Spectrum \u03b2-Lactamase-Producing Enterobacterales: Real-World Data from a Greek Tertiary Center"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9065-4811","authenticated-orcid":false,"given":"Vasileios","family":"Petrakis","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases, 2nd University Department of Internal Medicine, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petros","family":"Rafailidis","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, 2nd University Department of Internal Medicine, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3695-0759","authenticated-orcid":false,"given":"Andreas G.","family":"Tsantes","sequence":"additional","affiliation":[{"name":"Laboratory of Haematology and Blood Bank Unit, \u201cAttiko\u201d Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece"},{"name":"Microbiology Department, \u201cSaint Savvas\u201d Oncology Hospital, 11522 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-0674-3787","authenticated-orcid":false,"given":"Dimitrios","family":"Themelidis","sequence":"additional","affiliation":[{"name":"University Laboratory Department, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nikoleta","family":"Babaka","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, 2nd University Department of Internal Medicine, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petros","family":"Ouzounakis","sequence":"additional","affiliation":[{"name":"Infection Control Committee, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Georgios","family":"Lazaridis","sequence":"additional","affiliation":[{"name":"Infection Control Committee, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aikaterini","family":"Taniou","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandra","family":"Sarantopoulou","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4846-2178","authenticated-orcid":false,"given":"Dimitrios","family":"Papazoglou","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, 2nd University Department of Internal Medicine, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria","family":"Panopoulou","sequence":"additional","affiliation":[{"name":"University Laboratory Department, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Periklis","family":"Panagopoulos","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, 2nd University Department of Internal Medicine, University General Hospital of Alexandroupolis, Democritus University Thrace, 68100 Alexandroupolis, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Antimicrobial Resistance Collaborators (2022). 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Spectr."}],"container-title":["Journal of Clinical Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/16\/6414\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T13:27:46Z","timestamp":1787146066000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2077-0383\/15\/16\/6414"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,19]]},"references-count":38,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2026,8]]}},"alternative-id":["jcm15166414"],"URL":"https:\/\/doi.org\/10.3390\/jcm15166414","relation":{},"ISSN":["2077-0383"],"issn-type":[{"value":"2077-0383","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,19]]}}}