In vivo bioluminescence imaging of labile iron accumulation in a murine model of <i>Acinetobacter baumannii</i> infection

Significance Iron is a required metal nutrient for life, and its altered homeostasis is associated with a number of diseases. We present a bioluminescent reporter for visualizing iron pools in living animals, where iron-dependent uncaging of d -aminoluciferin enables sensitive and selective imaging of ferrous over ferric forms of iron in luciferase-expressing cell and mouse models. Application of this technology to a model of systemic bacterial infection reveals elevation of iron in infected tissues that accompany markers for increased iron acquisition and retention. These data establish the ability to assess iron status in living animals and provide a unique platform for studying its contributions to stages of health, aging, and disease.