Disruption of bbe02 by Insertion of a Luciferase Gene Increases Transformation Efficiency of Borrelia burgdorferi and Allows Live Imaging in Lyme Disease Susceptible C3H Mice
Fig 5
Spatial and temporal distribution of B. burgdorferi N40 bbe02::Bbluc-aadA in infected C3H mice.
Real-time imaging of the same set of infected mice on the day of inoculation and also at 7, 14 and 28 days after infection shows the presence of live B. burgdorferi. For imaging, each mouse was injected with 100 μl PBS containing 1.5 mg of D-luciferin intraperitoneally. Images were taken with 30 seconds of luminescent exposure time. (A) Images of three C3H mice injected with 10 spirochete of N40 bbe02::Bbluc-aadA per mouse from dorsal (Time 0) or ventral (later time points) side are shown. Similar images are shown for mice infected with 102 (B), or 103 (C) N40 bbe02::Bbluc-aadA spirochetes. Absence of light emission after four weeks of infection indicates that adaptive immune response has reduced B. burgdorferi levels below the sensitivity of detection of IVIS 200. The same minimum and maximum luminescence range were used in all images as indicated by color spectrum scale. (D) Determination of the level of colonization in head and joint regions of C3H mice by bioluminescence quantitation at 14 days of infection. Background threshold is marked by a dotted line. Mice that remain uninfected showed luminescence signal below the threshold value after luciferase injections and thus, provide ideal controls for background signal.