Retrospective Evaluation of the Incidence, Clinical Characteristics and Outcomes of Gram-Negative Bacterial Infections in Patients with Hematologic Malignancies.
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.
We conducted a retrospective cohort study in a tertiary university hospital hematology ward in Türkiye, 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.
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 β-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 < 0.0001), elevated CRP (p = 0.001), and higher procalcitonin levels (p = 0.046) were detected in non-survivors.
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.
We conducted a retrospective cohort study in a tertiary university hospital hematology ward in Türkiye, 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.
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 β-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 < 0.0001), elevated CRP (p = 0.001), and higher procalcitonin levels (p = 0.046) were detected in non-survivors.
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.
Authors
Aksoy Aksoy, Karakoc Parlayan Karakoc Parlayan, Agirman Agirman, Ozkaya Ozkaya, Sonmez Sonmez, Yilmaz Yilmaz
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