AUTHOR=Rua Marta , Simón Jon Ander , Collantes María , Ecay Margarita , Leiva José , Carmona-Torre Francisco , Ramos Rocío , Pareja Félix , Pulagam Krishna R. , Llop Jordi , Del Pozo José Luis , Peñuelas Iván 

TITLE=Infection-specific PET imaging with 18F-fluorodeoxysorbitol and 2-[18F]F-ρ-aminobenzoic acid: An extended diagnostic tool for bacterial and fungal diseases

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1094929

DOI=10.3389/fmicb.2023.1094929

ISSN=1664-302X

ABSTRACT=<sec><title>Introduction</title><p>Suspected infectious diseases located in difficult-to-access sites can be challenging due to the need for invasive procedures to isolate the etiological agent. Positron emission tomography (PET) is a non-invasive imaging technology that can help locate the infection site. The most widely used radiotracer for PET imaging (2-deoxy-2[<sup>18</sup>F] fluoro-D-glucose: [<sup>18</sup>F]FDG) shows uptake in both infected and sterile inflammation. Therefore, there is a need to develop new radiotracers able to specifically detect microorganisms.</p></sec><sec><title>Methods</title><p>We tested two specific radiotracers: 2-deoxy-2-[<sup>18</sup>F]-fluoro-D-sorbitol ([<sup>18</sup>F]FDS) and 2-[<sup>18</sup>F]F-ρ-aminobenzoic acid ([<sup>18</sup>F]FPABA), and also developed a simplified alternative of the latter for automated synthesis. Clinical and reference isolates of bacterial and yeast species (19 different strains in all) were tested <italic>in vitro</italic> and in an experimental mouse model of myositis infection.</p></sec><sec><title>Results and discussion</title><p>Non-lactose fermenters (<italic>Pseudomonas aeruginosa</italic> and <italic>Stenotrophomonas maltophilia</italic>) were unable to take up [<sup>18</sup>F]FDG <italic>in vitro</italic>. [<sup>18</sup>F]FDS PET was able to visualize Enterobacterales myositis infection (i.e., Escherichia coli) and to differentiate between yeasts with differential assimilation of sorbitol (i.e., <italic>Candida albicans</italic> vs. <italic>Candida glabrata</italic>). All bacteria and yeasts tested were detected <italic>in vitro</italic> by [<sup>18</sup>F]FPABA. Furthermore, [<sup>18</sup>F]FPABA was able to distinguish between inflammation and infection in the myositis mouse model (<italic>E. coli</italic> and <italic>Staphylococcus aureus</italic>) and could be used as a probe for a wide variety of bacterial and fungal species.</p></sec>