Imaging of bioluminescent Acinetobacter baumannii in a mouse pneumonia model

Bioluminescence imaging is a non-invasive tool for in vivo real-time monitoring of infectious disease progression in animal models. However, no bioluminescence imaging assay has been developed to monitor Acinetobacter baumannii infections. In the current study, bioluminescent strains of A. baumannii ATCC 17978 and its isogenic Delta ompA mutant were constructed by integrating the promoter of the ompA gene and the luxCDABE luciferase gene into the bacterial chromosome. In an acute murine pneumonia model, bioluminescence of the two reporter strains was clearly visible in the lungs and the bioluminescent signal increased over time. Bioluminescence was correlated with bacterial burden and histopathology in reporter strain-infected mice, suggesting that bioluminescent bacteria are useful for monitoring A. baumannii infections in animal models.