The rise of resistance against all known antibiotics is a global crisis. There is an urgent need to develop rapid and sensitive diagnostic methods to detect pathogenic bacteria in clinical samples. Pseudopaline, a metallophore produced by the human pathogen Pseudomonas aeruginosa, transports divalent metal ions via a dedicated active transport system, making it an ideal carrier for a second functional moiety. In this work, we have developed a fluorescein-labeled pseudopaline probe (P-FL), which could specifically detect P. aeruginosa in samples (in vitro) with many other bacterial species, mammalian cells, or mouse stomach tissue sections. By replacing the fluorescein with the near-infrared fluorophore Cy-7 (P-Cy7), we showed that P. aeruginosa infections could also be specifically detected in a mouse model (in vivo). The remarkable selectivity of these pseudopaline fluorescent probes is because the pseudopaline-mediated metal transport system is specific to P. aeruginosa only. Therefore, our results show that pseudopaline based probes may provide a new way to develop fast and effective diagnostics of P. aeruginosa infections.
The rise of resistance against all known antibiotics is a global crisis. There is an urgent need to develop rapid and sensitive diagnostic methods to detect pathogenic bacteria in clinical samples. Pseudopaline, a metallophore produced by the human pathogen Pseudomonas aeruginosa, transports divalent metal ions via a dedicated active transport system, making it an ideal carrier for a second functional moiety. In this work, we have developed a fluorescein-labeled pseudopaline probe (P-FL), which could specifically detect P. aeruginosa in samples (in vitro) with many other bacterial species, mammalian cells, or mouse stomach tissue sections. By replacing the fluorescein with the near-infrared fluorophore Cy-7 (P-Cy7), we showed that P. aeruginosa infections could also be specifically detected in a mouse model (in vivo). The remarkable selectivity of these pseudopaline fluorescent probes is because the pseudopaline-mediated metal transport system is specific to P. aeruginosa only. Therefore, our results show that pseudopaline based probes may provide a new way to develop fast and effective diagnostics of P. aeruginosa infections.