MAGNETIZATION TRANSFER CONTRAST MRI DETECTS PSEUDOMONAS AERUGINOSA BACTERIAL INFECTION A MOUSE BURN MODEL

Green Fluorescent Protein (GFP) is a widely used molecular and gene expression marker which is non-toxic for both animals and bacteria. Magnetization Transfer Contrast (MTC) MRI has been previously utilized to distinguish intrinsic macromolecule concentration changes. Published reports on in vivo MRI studies using GFP protein as a marker to label tumor or stem cells suggested that the labeling does not affect the gene expression. Recently, an MTC technique was used to detect GFP and was shown to produce protein-specific values that seemed to be concentration dependent. The use of an extrinsic protein marker provides an added flexibility. The main advantages of detecting GFP with MTC MRI over other MRI based reporters includes that there are multiple GFP mouse lines available and it poses no toxicity. This provides a flexible, non-invasive in vivo molecular imaging system exclusively dependent on the concentration of the reporter GFP. We report an in vivo study of GFP-tagged MTC MRI in a Burn mouse model infected with Pseudomonas aeruginosa. The goal of this study was to visualize bacterical infection in vivo in real time, and to study the impact of novel therapeutics on bacterial proliferation and viability within the host system.