Validation of MALDI-TOF diagnostic equipment for CNS speciation and development of intramammary infection risk models

Build and test a spectral library for speciation of CNS and investigate the impact of species-specific CNS infection on development of new major pathogen infection.


  • Research-validated spectroscopy-based diagnostic methods improved the species-specificity and accuracy of pathogen diagnosis.
  • Sixteen custom reference spectra which covered 10 different species of CNS were developed to enhance the performance of MALDI-ToF MS for CNS species identification. These custom reference spectra are being made available for use by both diagnostic laboratories and researchers that are adopting MALDI-ToF MS for bovine mastitis microbial identification and are improving the accuracy of mastitis diagnosis around the world.
  • According to the results of analysis on 5,827 isolates, Staphylococcus chromogenesrepresented 48.2% of the CNS, followed by S. simulans(16.7%), S. xylosus(11.2%), S. haemolyticus(7.8%), and S. epidermidis(4.0%).

Research Team

  • Jean-Philippe Roy (collaborator, UMontréal)
  • Marcelo Chaffer (collaborator, UPEI)
  • Greg Keefe (PrincipaI Investigator, UPEI)
    Not in photo: Marguerite Cameron (post-doctoral fellow, UPEI) and collaborators: Sarne De Vliegher (Ghent University), Kristen Reyher (UBristol), Catherine Anne Muckle (UPEI) and Jeffrey Lewis (UPEI)