Investigation of four (99m)Tc-labeled bacteriophages for infection-specific imaging

Nucl Med Biol. 2008 May;35(4):433-40. doi: 10.1016/j.nucmedbio.2008.02.011.


Introduction: This study investigated radiolabeled bacteriophages for specific detection of infection through gamma imaging. Previously, a (99m)Tc-labeled M13 phage demonstrated specific binding for its host Escherichia coli in vitro and in mice through imaging.

Methods: This study was extended to phages P22, E79, VD-13 and phage 60. Each was radiolabeled with (99m)Tc using the chelator MAG(3), and were evaluated for binding to host and non-host bacteria in vitro and in a mouse infection model.

Results: In vitro, each (99m)Tc-phage bound to its host at least 4-fold higher than to non-host bacteria. For example, (99m)Tc-E79 showed 10- to 20-fold greater binding to host Pseudomonas aeruginosa compared to non-host Escherichia coli and Salmonella enterica, and (99m)Tc-phage 60 showed 20-fold greater binding to host Klebsiella pneumoniae over non-hosts. Mice received host or non-host bacteria in one thigh, and 3 h later, the (99m)Tc-phages were administered intravenously. After a further 3 h, the tissues were counted. Liver accumulation was highest for (99m)Tc-E79, averaging 39% compared to an average of 13% for the other (99m)Tc-phages. Animals infected with host bacteria showed infected thigh/normal thigh ratios of 14.2 for (99m)Tc-E79, 2.9 for (99m)Tc-P22, 3.5 for (99m)Tc-VD-13 and 2.1 for (99m)Tc-phage 60.

Conclusions: Although specific host binding was observed in vitro for each of these four (99m)Tc-phages, only (99m)Tc-E79 showed specificity for its host in an in vivo model.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bacteria / virology*
  • Bacterial Infections / diagnostic imaging*
  • Bacteriophages* / chemistry
  • Bacteriophages* / pathogenicity
  • Disease Models, Animal
  • Escherichia coli / virology
  • Host-Pathogen Interactions
  • Infections / diagnostic imaging*
  • Isotope Labeling / methods
  • Klebsiella pneumoniae / virology
  • Male
  • Mice
  • Pseudomonas aeruginosa / virology
  • Radionuclide Imaging
  • Radiopharmaceuticals / chemistry
  • Radiopharmaceuticals / pharmacokinetics
  • Salmonella enterica / virology
  • Sodium Pertechnetate Tc 99m / chemistry
  • Sodium Pertechnetate Tc 99m / pharmacokinetics*
  • Species Specificity
  • Tissue Distribution


  • Radiopharmaceuticals
  • Sodium Pertechnetate Tc 99m