Methods: An in vivo bioluminescence imaging method was established using stably luminescent S. aureus strain SAP149. SAP149 (1×107 CFU) was IV injected into SCID mice. At 24 hr post-infection, mice were given either: a single IV dose of TAC at 15, 50, or 100 mg/kg; repeated intraperitoneal (IP) doses of vancomycin at 110 mg/kg twice per day (BID) for 7 days; or repeated IP doses of saline control BID for 7 days. In vivo bioluminescence imaging was acquired with IVIS-Lumina-II to continuously monitor the total body bioluminescence intensity for 21 days post treatment.
Results: The imaging data (Figure 2) showed a rapid and significant reduction of the bioluminescence intensity after TAC treatment compared to the control group. In addition, the reduction of bioluminescence intensity was maintained for 7 to 21 days after a single dose of TAC, while bioluminescence intensity rebounded immediately after stopping vancomycin on day 7.
Conclusion: We have applied an imaging method to longitudinally assess the antibacterial dynamics of TAC and vancomycin treatment in vivo over a 3-week period. The imaging data demonstrated the superior and sustained antibacterial activity of TAC over vancomycin.
S. Ramanujan, Genentech: Employee , Salary
T. Pillow, Genentech: Employee , Salary
M. Yang, None
F. Guo, None
D. Xu, None
A. Kamath, Genentech: Employee , Salary