UCSF

Purpose: The goal of this study was to investigate a panel of D-amino acids and select potential probe candidates for imaging bacterial infections in vivo.

Methods: Uptake of radiolabeled D-amino acids was tested in E. coli. Selection of candidates was based on the following criteria: (1) high uptake in E. coli and (2) ease of 18F labeled analog synthesis. Selected D-amino acid candidates were then tested for uptake and specificity in E. coli at several time points and with coadministration of non-radioactive D-amino acid blocking dose. 18F D-Phenylalanine was synthesized to test uptake in E. coli over time. 18F-FDG was tested for uptake and specificity in E. coli at several time points and with coadministration of non-radioactive Cytochalasin B blocking dose.

Results: D-Methionine showed the highest uptake in E. coli. D-Methionine uptake increased over time in E. coli and showed specific uptake. D-Phenylalanine uptake increased over time in E. coli and showed specific uptake. 18F D-Phenylalanine showed higher uptake in E. coli and showed more bacteria specific uptake than 18F-FDG.

Conclusion: D-Methionine and D-Phenylalanine were selected as potential probe candidates for imaging bacterial infections in vivo.