AUTHOR=Costa Silva Alberto , Pina-Vaz Teresa , Pinho Ana , Ferreira Inês , Cerqueira Ana , Bustorff Manuela , Sampaio Susana , Roncon-Albuquerque Roberto , Rios Margarida , Pestana Manuel , Martins-Silva Carlos , Antunes-Lopes Tiago , Alturas Silva João TITLE=Preservation Fluid Bacteriology in Kidney Transplantation: Comparing Uncontrolled Donation After Circulatory Death With Donation After Brain Death JOURNAL=Transplant International VOLUME=Volume 38 - 2025 YEAR=2025 URL=https://www.frontierspartnerships.org/journals/transplant-international/articles/10.3389/ti.2025.14855 DOI=10.3389/ti.2025.14855 ISSN=1432-2277 ABSTRACT=Infectious complications remain a significant concern in organ transplantation, and preservation fluid (PF) has been identified as a potential source of microbial contamination. However, the clinical relevance of positive PF cultures, especially in kidney transplants from uncontrolled donation after circulatory death (uDCD), is not clearly established. This study aims to evaluate and compare the incidence and clinical implications of positive PF cultures in kidney transplants from uDCD and donation after brain death (DBD) donors. A prospective, single-center study was conducted, involving 497 kidney transplants—147 from uDCD and 350 from DBD donors. PF samples were systematically collected at the time of transplantation, cultured, and analyzed. The type of bacteria identified guided antibiotic treatment decisions. Recipients were monitored for the development of bacteremia within the first post-transplant week. Positive PF cultures were significantly more frequent in uDCD transplants (32.0%) compared to DBD (13.7%) (p < 0.001). Coagulase-negative staphylococci predominated in both groups. Despite this, bacteremia rates were comparable—8.5% in uDCD and 6.3% in DBD (p = 0.673)—with no culture-concordant cases. Antibiotics were administered to 10.6% of uDCD and 22.9% of DBD recipients (p = 0.110). Although uDCD kidneys had higher PF contamination, the clinical impact was minimal.