Bimodal Labelling of S. Aureus for Detection of Bacterial Colonization in Skin Infections by MRI

Verena Hoerr¹, Lorena Tuchscherr², Bettina Loeffler², Lydia Wachsmuth¹, Klaus Strobel¹, Florian Schmid¹, Cornelius Faber¹

We have developed a protocol for labelling S. aureus with rhodamine coated iron-oxide particles (VSOPs). In mouse models of S. aureus infection we were able to visualize bacterial colonies in tissue and to distinguish infection from inflammation both by MRI and Fluorescence Reflectance Imaging (FRI). Using ultra-short echo-time imaging (UTE) and FLASH with complementary image contrast iron particles in bacterial colonization were detected and confirmed by fluorescence imaging. To the best of our knowledge we present the first MRI visualization of S. aureus colonization in mouse models in vivo.