Therapeutic efficacy of buforin II and rifampin in a rat model of Acinetobacter baumannii sepsis

Objective. To investigate the efficacy of buforin II and rifampin in an experimental rat model of Acinetobacter baumannii sepsis. Design: Prospective, randomized, controlled animal study. Setting: Research laboratory in a university hospital. Subjects: Adult male Wistar rats. Interventions: The animals received intraperitoneally 1 mL saline containing 2 x 10(10) colony forming units of A. baumannii ATCC 19606 (model i) or the multiresistant strain (model ii). Immediately after bacterial challenge, animals received intravenously a single dose of isotonic sodium chloride solution (control groups C-1 and C-2, 1 mg/kg of buforin II, 10 mg/kg of rifampin, and 1 mg/kg of buforin II plus 10 mg/kg of rifampin, respectively. Measurements and Main Results: Lethality, bacterial growth in blood and tissue burden, endotoxin, interleukin-6, and tumor necrosis factor-alpha concentrations in plasma. Buforin II showed good antimicrobial activity and achieved a significant reduction of plasma endotoxin and cytokines concentration when compared with control and rifampin-treated groups. Combination among buforin II proved to be the most effective treatment in reducing all variables measured. Conclusion. In an experimental model, buforin II and rifampin might have a potential role in the treatment of severe infections due to A. baumannii. (Crit Care Med 2009; 37:1403-1407)