{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T19:21:22Z","timestamp":1790882482123,"version":"4.1.0"},"reference-count":31,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background: Difficult-to-treat resistant Pseudomonas aeruginosa (DTR-PA) infections are associated with high morbidity and mortality, but data on prognostic factors remain limited. Given the limited real-world data on outcomes of DTR-PA infections, we aimed to identify clinical predictors of mortality and response to therapy in this setting. Methods: We conducted a single-center retrospective cohort study of 51 patients with DTR-PA infections. The primary endpoint was 30-day all-cause mortality; secondary endpoints were clinical and microbiological cure at end of therapy. An exploratory analysis evaluated 30-day infection-related mortality. Logistic regression models (univariable, multivariable and Firth bias-reduced) were used to identify independent predictors. Results: Median age was 64 years (IQR 22); 63% were male and 71% were in the ICU at infection onset. Sepsis occurred in 80% and septic shock in 45%. Thirty-day all-cause mortality was 49% (25\/51). According to multivariable analysis, septic shock was an independent predictor of mortality (aOR 5.52, 95% CI 1.04\u201329.27; p = 0.045) as younger age (aOR 1.06, 95% CI 1.00\u20131.12; p = 0.052), whereas targeted therapy with ceftazidime\/avibactam or ceftolozane\/tazobactam is a protective factor (aOR 0.15, 95% CI 0.02\u20131.17; p = 0.070) did not reach significance in the final model. Clinical cure occurred in 33% (17\/51) and was negatively associated with device burden and bloodstream infection, whereas microbiological cure (45%, 23\/51) was more likely with targeted therapy and absence of sepsis. The exploratory analysis of infection-related mortality (35%) showed similar predictors. Conclusions: DTR-PA infections are associated with high mortality. Septic shock and older age predict death, while the use of novel \u03b2-lactam\/\u03b2-lactamase inhibitors is associated with improved outcomes. Early recognition of severe illness and timely administration of active therapy may improve survival in these infections.<\/jats:p>","DOI":"10.3390\/antibiotics15010033","type":"journal-article","created":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T11:11:46Z","timestamp":1767352306000},"page":"33","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Clinical Outcomes and Predictors of Mortality in Patients with Difficult-to-Treat Resistant Pseudomonas aeruginosa Infections: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7218-7762","authenticated-orcid":false,"given":"Alberto Enrico","family":"Maraolo","sequence":"first","affiliation":[{"name":"Section of Infectious Diseases, Department of Clinical Medicine and Surgery, University of Naples \u201cFederico II\u201d, 80138 Naples, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7274-2068","authenticated-orcid":false,"given":"Antonella","family":"Gallicchio","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Department of Clinical Medicine and Surgery, University of Naples \u201cFederico II\u201d, 80138 Naples, Italy"},{"name":"VIII Infectious Disease Unit, P.O. Cotugno, A.O.R.N. dei Colli, 80131 Naples, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-0723-495X","authenticated-orcid":false,"given":"Vincenzo","family":"Fotticchia","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Department of Clinical Medicine and Surgery, University of Naples \u201cFederico II\u201d, 80138 Naples, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8765-137X","authenticated-orcid":false,"given":"Maria Rosaria","family":"Catania","sequence":"additional","affiliation":[{"name":"Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, 80131 Napoli, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0178-2986","authenticated-orcid":false,"given":"Riccardo","family":"Scotto","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Department of Clinical Medicine and Surgery, University of Naples \u201cFederico II\u201d, 80138 Naples, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5199-8451","authenticated-orcid":false,"given":"Ivan","family":"Gentile","sequence":"additional","affiliation":[{"name":"Section of Infectious Diseases, Department of Clinical Medicine and Surgery, University of Naples \u201cFederico II\u201d, 80138 Naples, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"861","DOI":"10.1080\/14787210.2017.1367666","article-title":"Management of multidrug-resistant Pseudomonas aeruginosa in the intensive care unit: State of the art","volume":"15","author":"Maraolo","year":"2017","journal-title":"Expert Rev. 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