- Parker, Matthew FL;
- López-Álvarez, Marina;
- Alanizi, Aryn A;
- Luu, Justin M;
- Polvoy, Ilona;
- Sorlin, Alexandre M;
- Qin, Hecong;
- Lee, Sanghee;
- Rabbitt, Sarah J;
- Pichardo-González, Priamo A;
- Ordonez, Alvaro A;
- Blecha, Joseph;
- Rosenberg, Oren S;
- Flavell, Robert R;
- Engel, Joanne;
- Jain, Sanjay K;
- Ohliger, Michael A;
- Wilson, David M
Background
Vertebral discitis-osteomyelitis (VDO) is a devastating infection of the spine that is challenging to distinguish from noninfectious mimics using computed tomography and magnetic resonance imaging. We and others have developed novel metabolism-targeted positron emission tomography (PET) radiotracers for detecting living Staphylococcus aureus and other bacteria in vivo, but their head-to-head performance in a well-validated VDO animal model has not been reported.Methods
We compared the performance of several PET radiotracers in a rat model of VDO. [11C]PABA and [18F]FDS were assessed for their ability to distinguish S aureus, the most common non-tuberculous pathogen VDO, from Escherichia coli.Results
In the rat S aureus VDO model, [11C]PABA could detect as few as 103 bacteria and exhibited the highest signal-to-background ratio, with a 20-fold increased signal in VDO compared to uninfected tissues. In a proof-of-concept experiment, detection of bacterial infection and discrimination between S aureus and E coli was possible using a combination of [11C]PABA and [18F]FDS.Conclusions
Our work reveals that several bacteria-targeted PET radiotracers had sufficient signal to background in a rat model of S aureus VDO to be potentially clinically useful. [11C]PABA was the most promising tracer investigated and warrants further investigation in human VDO.