[68Ga]Ga-Ornibactin for Burkholderia cepacia complex Infection Imaging Using Positron Emission Tomography

Bacteria from the Burkholderia cepacia complex are generally consideredto be non-pathogenic to the healthypopulation. However, some of these species may cause serious nosocomialinfections in immunocompromised patients; as such, it is essentialto diagnose these infections rapidly so that adequate treatment canbe initiated. We report here the use of a radiolabeled siderophore,ornibactin (ORNB), for positron emission tomography imaging. We successfullyradiolabeled ORNB with gallium-68 with high radiochemical purity andproved that the resulting complex has optimal in vitro characteristics. In mice, the complex did not show excessive accumulationin organs and was excreted in the urine. We demonstrated that the[Ga-68]-Ga-ORNB complex accumulates at the site of Burkholderia multivorans infection, including pneumonia,in two animal infection models. These results suggest that [Ga-68]-Ga-ORNB is a promising tool for the diagnosis, monitoring, andevaluation of the therapeutic response to B. cepacia complex infection.