Guanshu Liu1, 2, Yuan Qiao3, Chetan Bettegowda3, Verena Staedtke3, Kannie W.Y. Chan4, 5, Renyuan Bai3, Gregory Riggins3, Kenneth W. Kinzler3, Jeff W.M. Bulte4, 5, Michael T. McMahon1, 2, Assaf A. Gilad4, 5, Bert Vogelstein3, Shibin Zhou3, Peter C.M. van Zijl1, 2
1F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States; 2Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 3Ludwig Center, Howard Hughes Medical Institute and Sidney Kimmel Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, United States; 4Department of Radiology, Johns Hopkins University, Baltimore, MD, United States; 5Cellular Imaging Section, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, United States
Currently there are no MRI methods to image bacterial infection. Here, we show that Chemical Exchange Saturation Transfer (CEST) provides a non-invasive MR imaging method to detect bacteria in live mice. Using this approach, we were able to detect two bacteria strains, C. novyi-NT and E. Coli, in vitro. As a first demonstration, we applied this approach to bacteriolytic therapy, which has recently emerged as a promising approach for treating cancer and is currently being translated to the clinic. The results show that CEST-MRI can monitor the infection of anaerobic bacteria in the hypoxic cores of solid tumors.