{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T23:41:05Z","timestamp":1788392465973,"version":"build-2803163510"},"reference-count":34,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2025,12,4]],"date-time":"2025-12-04T00:00:00Z","timestamp":1764806400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Background: Patients with hematologic malignancies are highly vulnerable to Gram-negative bacterial bloodstream infections (GNB-BSIs) due to underlying disease-related immunosuppression, intensive chemotherapy, and repeated invasive interventions, rendering these infections a significant cause of morbidity and mortality in this population. This study aimed to evaluate the epidemiological, clinical, and microbiological features of GNB-BSIs in hospitalized patients with hematologic malignancies, and to compare clinical and microbiological factors between survivors and non-survivors. Methods: We conducted a retrospective cohort study in a tertiary university hospital hematology ward in T\u00fcrkiye, including adult patients diagnosed with BSIs due to Gram-negative bacteria between January 2005 and December 2024. Demographic characteristics, microbiological profiles, antimicrobial resistance rates, and clinical outcomes were analyzed. We compared survivors and non-survivors to determine differences in clinical and microbiological characteristics. Results: A total of 321 patients with hematologic malignancies experienced 441 episodes of GNB-BSIs. The median age was 46 years, and 59% of them were male. The most frequently isolated pathogen was Escherichia coli (53.3%), followed by Klebsiella spp. (20.6%) and Pseudomonas spp. (7.5%). Extended-spectrum \u03b2-lactamase-producing\/third-generation cephalosporin-resistant (ESBL\/3GCR) and carbapenem-resistant isolates were observed in 21.1% and 13.3% of isolates, respectively. The overall mortality rate was 26.5%. ICU admission, multidrug resistance, and persistent bacteremia were observed more often among non-survivors. Additionally, prolonged fever duration (median 8 vs. 3 days, p &lt; 0.0001), elevated CRP (p = 0.001), and higher procalcitonin levels (p = 0.046) were detected in non-survivors. Conclusions: In patients with hematologic malignancies, E. coli and Klebsiella spp. remain the predominant pathogens causing bloodstream infections, while persistent bacteremia, ESBL\/3GCR, and carbapenem resistance are associated with higher mortality. Notably, carbapenem resistance showed a temporal increase over the study period, underscoring the need for continuous surveillance and timely adaptation of empirical treatment strategies.<\/jats:p>","DOI":"10.3390\/pathogens14121238","type":"journal-article","created":{"date-parts":[[2025,12,4]],"date-time":"2025-12-04T15:14:06Z","timestamp":1764861246000},"page":"1238","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Retrospective Evaluation of the Incidence, Clinical Characteristics and Outcomes of Gram-Negative Bacterial Infections in Patients with Hematologic Malignancies"],"prefix":"10.3390","volume":"14","author":[{"given":"Firdevs","family":"Aksoy","sequence":"first","affiliation":[{"name":"Department of Infectious Disease and Clinical Microbiology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4620-6755","authenticated-orcid":false,"given":"Hanife Nur","family":"Karakoc Parlayan","sequence":"additional","affiliation":[{"name":"Department of Infectious Disease and Clinical Microbiology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Munire","family":"Agirman","sequence":"additional","affiliation":[{"name":"Department of Infectious Disease and Clinical Microbiology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1673-9101","authenticated-orcid":false,"given":"Esra","family":"Ozkaya","sequence":"additional","affiliation":[{"name":"Department of Medical Microbiology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehmet","family":"Sonmez","sequence":"additional","affiliation":[{"name":"Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gurdal","family":"Yilmaz","sequence":"additional","affiliation":[{"name":"Department of Infectious Disease and Clinical Microbiology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.cmi.2024.09.015","article-title":"Prevention and treatment of bacterial infections in patients with haematological cancers and haematopoietic stem cell transplantation: Headways and shortcomings","volume":"31","author":"Er","year":"2025","journal-title":"Clin. 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