Red-shifted firefly luciferase optimized for Candida albicans in vivo bioluminescence imaging

The authors of this study attempted to compare the performance of BLI in the present study with that published using the systemic infection model and light detection in the region of the kidneys. They estimated that a lower limit of detection for BLI (50 photon/s/mm2) corresponded to of about 200 CFU/kidney with the instrumentation used here (in-vivo Xtreme II). Given numbers published by Jacobsen et al. (2014) (100 photon/s/mm2 for 3,600 CFU/kidney), this suggests that the method used here increases at least by 4- to 8-fold the sensitivity of C. albicans detection.
This performance can be attributed to several factors including (i) the type of luciferase used (Mut2 has better tissue penetration capacities than the wild type luciferase) and (ii) technical differences provided by the luminescence acquisition of instruments. This performance is even more remarkable when taking in account that BLI data was collected here from animals contained in Sealed Optical Imaging Trays, which may create another obstacle of emitted light to the high sensitivity camera.

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