Imaging of a localized bacterial infection with endogenous thymidine kinase using radioisotope-labeled nucleosides.

Abstract

The importance of noninvasive imaging methods to bacterial infections is widely recognized. To obtain bacterial infection imaging with radioisotope-labeled nucleosides, bacterial thymidine kinase (tk) activities of Salmonella typhimurium with [(125)I]5-iodo-1-(2'-fluoro-2'-deoxy-β-d-arabinofuranosyl)uracil ([(125)I]FIAU) or 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) were measured. The infection model in BALB/c mice was imaged with [(125)I]FIAU or [(18)F]FLT using small-animal Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET), respectively. The accumulated radioactivity of [(125)I]FIAU or [(18)F]FLT in the two strains showed a linearly increased pattern with increasing incubation time or bacterial numbers. The image clearly demonstrated a high uptake of [(125)I]FIAU and [(18)F]FLT in the bacterial infection site. [(18)F]FLT uptake in the infection site of was 7.286±2.405, whereas that in the uninfected site was 0.519±0.561. The relative activity ratio of the infected region in relation to the uninfected region was 2.98 at 4h after an injection with [(125)I]FIAU determined by biodistribution data. In conclusion, the bacterial tk activity was confirmed by the cellular uptake and imaging with [(125)I]FIAU or [(18)F]FLT. Therefore, a localized bacterial infection in living mice can be monitored using radioisotope-labeled nucleosides with a nuclear medicine imaging modality.

• Authors: Su Jin Jang, Yong Jin Lee, Sangyong Lim, Kwang Il Kim, Kyo Chul Lee, Gwang Il An, Tae Sup Lee, Gi Jeong Cheon, Sang Moo Lim, Joo Hyun Kang
• Journal: International journal of medical microbiology : IJMM (Int J Med Microbiol) Vol. 302 Issue 2 Pg. 101-7 (Mar 2012) ISSN: 1618-0607 [Electronic] Germany
• PMID: 22264560 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2012 Elsevier GmbH. All rights reserved.

Chemical References

• Dideoxynucleosides
• Iodine Radioisotopes
• Radiopharmaceuticals
• Arabinofuranosyluracil
• fialuridine
• Thymidine Kinase
• alovudine

Topics

• Animals
• Arabinofuranosyluracil (analogs & derivatives)
• Bacterial Infections (diagnostic imaging, metabolism)
• Dideoxynucleosides
• Focal Infection (diagnostic imaging, metabolism)
• Gene Expression
• Iodine Radioisotopes
• Mice
• Mice, Inbred BALB C
• Molecular Imaging
• Positron-Emission Tomography
• Radiopharmaceuticals
• Salmonella typhimurium (enzymology, genetics)
• Thymidine Kinase (analysis)
• Tomography, Emission-Computed, Single-Photon