Risk factors for carbapenem-resistant Acinetobacter baumannii (CRAB) infections in critically ill patients with previous CRAB colonization: a multicentre cohort study Francesco Cogliati Dezza, Belén Gutiérrez-Gutiérrez, Giusy Tiseo, Sara Covino, Flavia Petrucci, et al. Jac Antimicrobial Resistance, 2026 Background Among MDR bacteria, carbapenem-resistant Acinetobacter baumannii (CRAB) is a major concern due to the limited therapeutic options. Objectives To identify predictors to aid in the clinical management of critically ill patients. Methods We conducted a multicentre prospective study in Italy, enrolling patients with CRAB colonization who were admitted to ICUs between 2020 and 2023. Multivariable logistic regression analysis was performed to identify potential risk factors for CRAB infection. To account for competing risks, we used the cumulative incidence function (CIF) and Fine–Gray regression analysis, providing an accurate assessment of the risk of CRAB infection. Additionally, a logistic regression model was performed to estimate the impact of different types of critically ill patients on the risk of infection. Results We included 564 colonized patients, and 381 (67.5%) developed a CRAB infection in the ICU. In the logistic regression model, multisite colonization (OR 2.78; 95% CI: 1.90–4.08; P < 0.001), Charlson comorbidity index (CCI) ≥3 (OR 1.59; 95% CI: 1.00–2.50; P = 0.047), mechanical ventilation (OR 1.48; 95% CI: 1.00–2.18; P = 0.048), male gender (OR 2.06; 95% CI: 1.38–3.10; P < 0.001), and time from ICU admission to colonization ≤12 days (OR 2.00; 95% CI: 1.36–2.94; P < 0.001) were independent predictors of CRAB infection. Findings were confirmed in the Fine–Gray model. In a secondary model, COVID-19 (OR 2.31; 95% CI: 1.30–4.10; P = 0.004) and burn patients (OR 4.84; 95% CI: 1.65–14.17; P = 0.004) were risk factors for CRAB infection. Conclusions Early colonization from ICU admission, multisite colonization, CCI, mechanical ventilation and male gender are key risk factors for CRAB infection. These factors support clinicians in the management of critically ill patients with prior CRAB colonization.
Carbapenemase type and mortality in blood-stream infections caused by carbapenemase-producing enterobacterales: a multicenter retrospective cohort study Yaakov Dickstein, Dafna Yahav, Giusy Tiseo, Cristina Mussini, Erica Franceschini, et al. Infection, 2025 Background Previous studies analyzing differences in mortality associated with carbapenemase type in patients with a variety of infections caused by carbapenemase-producing Enterobacterales (CPE) have produced conflicting results. Methods We performed a multinational multicenter retrospective cohort study. Adult patients with blood-stream infections (BSI) caused by CPE between 2015 and 2020 were included. The primary outcome was 14-day mortality; 28-day mortality and microbiological failure were secondary outcomes. Clinical and microbiological data were collected and analyzed using conditional logistic regression. Results A total of 360 patients were identified of whom 226 had infections caused by KPC-producing isolates, 109 by NDM-producing isolates and 25 by other carbapenemases. Definitive therapy was colistin-based in 35.1% of patients, ceftazidime/avibactam ± aztreonam (CAZ/AVI ± A) in 28.2% and other in 23.4%. Overall 14-day mortality was 28.1%; carbapenemase type was unassociated with mortality in univariate or multivariate analyses. Antimicrobial therapy was significantly associated with 14-day mortality: patients treated with CAZ/AVI ± A had an adjusted hazard ratio of 0.172 (95% confidence interval 0.063–0.473) for death as compared to patients treated with colistin-based therapy. At 28 days, overall mortality was 35.3%; no association was observed between carbapenemase type and 28-day mortality or microbiological failure. Conclusion After controlling for antimicrobial therapy, we did not find evidence of an association between carbapenemase type and mortality. Ceftazidime/avibactam was associated with a greater than 80% reduction in mortality as compared with colistin.
Managing skin infections in burn patients: principles and pitfalls Giusy Tiseo, Sara Occhineri, Marco Falcone Current Opinion in Infectious Diseases, 2025 Purpose of review Burn wound infections pose a major challenge in both critical care and surgical settings, owing to the complex interplay of host immune dysfunction, altered pharmacokinetics, surgical wound dynamics, and the high prevalence of multidrug-resistant (MDR) organisms. This review summarizes current evidence on diagnosis, antimicrobial therapy, and multidisciplinary management of burn wound infections, highlighting common pitfalls and strategies to mitigate them. Recent findings Burn patients display a distinct microbiological profile that evolves over time: Gram-positive cocci initially predominate, whereas nonfermenting Gram-negative bacilli such as Pseudomonas aeruginosa and Acinetobacter baumannii become increasingly prevalent during hospitalization. Differentiating colonization from infection remains a major diagnostic challenge. Although tissue biopsy is the gold standard for confirming wound infection, it is not uniformly implemented across centers. Therefore, a comprehensive clinical and microbiological evaluation involving infectious disease specialists, intensivists, and surgeons is essential for accurate interpretation of wound status. Antimicrobial stewardship interventions, including pharmacokinetic/pharmacodynamic optimization, therapeutic drug monitoring, carbapenem-sparing regimens, shorter antibiotic courses, and avoidance of redundant combination therapies, are key components of burn infection management. New agents, such as β-lactam/β-lactamase inhibitor combinations and novel tetracyclines, show promise against MDR nonfermenting Gram-negative pathogens. Summary A structured, multidisciplinary team offers the most effective framework for improving outcomes in burn wound infections. Optimizing diagnostics, individualizing antimicrobial therapy, and aligning surgical timing with infection control measures are fundamental pillars. Future research should focus on prospective validation of integrated care pathways and on evaluating the real-world effectiveness of novel antimicrobial agents in burn-injured patients.
Comparative effectiveness of echinocandins and liposomal amphotericin B for fluconazole-resistant Candida parapsilosis bloodstream infections Antonio Vena, Claudia Bartalucci, Marco Muccio, Giusy Tiseo, Patricia Muñoz, et al. Antimicrobial Agents and Chemotherapy, 2025 Current therapeutic options for fluconazole-resistant Candida parapsilosis (FLZR-CP) bloodstream infections (BSI) are limited to echinocandins and liposomal amphotericin B (L-AmB). To the best of our knowledge, no real-world comparative effectiveness studies have assessed these agents. This study aimed to compare the effectiveness of echinocandins and L-AmB for the treatment of FLZR-CP BSI. This retrospective, observational study was conducted in two hospitals in Italy between January 2018 and December 2022. Eligible patients were adults (≥18 years old) with microbiologically confirmed FLZR-CP BSI who received targeted therapy with either echinocandins or L-AmB. Patients were matched (2:1) based on age, Charlson comorbidity index, presence of sepsis or septic shock, time to appropriate antifungal therapy (≤48 hours or > 48 hours from diagnosis), and infection source. A total of 63 patients were included (42 in the echinocandin group and 21 in the L-AmB group). In Cox regression, targeted therapy with echinocandins was not associated with increased mortality (adjusted hazard ratio 1.40; 95% confidence interval [CI] 0.33–5.92, P = 0.645). An exploratory sensitivity analysis including patients who did not receive source control yielded consistent results ( P = 0.491). Furthermore, in the multivariable regression analysis, echinocandin therapy was not associated with an increased risk of persistent fungemia (adjusted odds ratio 1.61: 95% CI 0.43–5.99, P = 0.476). Treatment with echinocandins and L-AmB resulted in similar 30-day mortality and persistent fungemia rates in patients with FLZR-CP BSI. These findings confirm that echinocandins are a viable treatment option for C. parapsilosis BSI, even for patients with fluconazole-resistant strains.
