Characteristics comparisons of bacteremia in allogeneic and autologous hematopoietic stem cell-transplant recipients with levofloxacin prophylaxis and influence on resistant bacteria emergence

Background: The aim of this study was to compare the risk factors and clinical outcomes of bacteremia in allogeneic and autologous hematopoietic stem cell transplant (allo-HSCT and auto-HSCT) recipients with levofloxacin prophylaxis during the early period after transplantation. Methods: Characteristics of bacteremia within 45 days after transplantation between allo-HSCT and auto-HSCT recipients who received levofloxacin prophylaxis between January 2005 and December 2014 were retrospectively reviewed. Results: Of 105 HSCT recipients included in this study, 55 (52.4%) received an allo-HSCT and 50 (47.6%) received an auto-HSCT. Twenty-five patients (23.8%) with HSCT developed 28 episodes of bacteremia. Of these 25 bacteremia patients, 15 received an allo-HSCT, while 10 received an auto-HSCT. The occurrence of Grade 3–4 graft-versus-host disease and longer engraftment duration were associated with bacteremia in allo- and auto-HSCT recipients (p = 0.001 and p = 0.002, respectively). Auto-HSCT recipients with bacteremia had a longer hospital stay after transplantation, while allo-HSCT recipients with bacteremia had an increased 45-day mortality rate as compared with those without bacteremia (p = 0.014 and p = 0.013, respectively). All 14 Gram-negative blood isolates in this study were resistant to fluoroquinolone. Conclusion: Levofloxacin prophylaxis in HSCT recipients is associated with the emergence of fluoroquinolone-resistant Gram-negative bacteria. The risk factors and clinical outcomes of bacteremia differ between allo- and auto-HSCT recipients, and these differences should be taken into account when designing strategies to prevent bacteremia.