Development of a Staphylococcus aureus reporter strain with click beetle red luciferase for enhanced in vivo imaging of experimental bacteremia and mixed infections

Sci Rep. 2019 Nov 13;9(1):16663. doi: 10.1038/s41598-019-52982-0.


In vivo bioluminescence imaging has been used to monitor Staphylococcus aureus infections in preclinical models by employing bacterial reporter strains possessing a modified lux operon from Photorhabdus luminescens. However, the relatively short emission wavelength of lux (peak 490 nm) has limited tissue penetration. To overcome this limitation, the gene for the click beetle (Pyrophorus plagiophtalamus) red luciferase (luc) (with a longer >600 emission wavelength), was introduced singly and in combination with the lux operon into a methicillin-resistant S. aureus strain. After administration of the substrate D-luciferin, the luc bioluminescent signal was substantially greater than the lux signal in vitro. The luc signal had enhanced tissue penetration and improved anatomical co-registration with infected internal organs compared with the lux signal in a mouse model of S. aureus bacteremia with a sensitivity of approximately 3 × 104 CFU from the kidneys. Finally, in an in vivo mixed bacterial wound infection mouse model, S. aureus luc signals could be spectrally unmixed from Pseudomonas aeruginosa lux signals to noninvasively monitor the bacterial burden of both strains. Therefore, the S. aureus luc reporter may provide a technological advance for monitoring invasive organ dissemination during S. aureus bacteremia and for studying bacterial dynamics during mixed infections.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bacteremia / diagnostic imaging
  • Bacteremia / metabolism
  • Bacteremia / microbiology*
  • Coinfection / diagnostic imaging
  • Coinfection / metabolism
  • Coinfection / microbiology*
  • Coleoptera / enzymology*
  • Coleoptera / genetics
  • Diagnostic Imaging / methods
  • Female
  • Genes, Reporter
  • Luciferases / genetics
  • Luciferases / metabolism*
  • Luminescent Measurements
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Pseudomonas Infections / diagnostic imaging
  • Pseudomonas Infections / metabolism
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / isolation & purification
  • Pseudomonas aeruginosa / metabolism
  • Rabbits
  • Staphylococcal Infections / diagnostic imaging
  • Staphylococcal Infections / metabolism
  • Staphylococcal Infections / microbiology*
  • Staphylococcus aureus / isolation & purification
  • Staphylococcus aureus / metabolism
  • Wound Infection / diagnostic imaging
  • Wound Infection / metabolism
  • Wound Infection / microbiology*


  • Luciferases