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 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 C1 and C2), 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.