MALDI-TOF-MS for rapid detection of staphylococcal Panton-Valentine leukocidin

Int J Antimicrob Agents. 2009 Nov;34(5):467-70. doi: 10.1016/j.ijantimicag.2009.03.017. Epub 2009 May 5.

Abstract

Toxin-producing gram-positive bacteria are responsible for emerging and life-threatening infections in humans worldwide. Both rapid toxin detection and adapted therapy are essential to limit the morbidity due to such toxins, especially staphylococcal Panton-Valentine leukocidin (PVL). Here we describe the use of a mass spectrometry profile generated by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) followed by ClinProTools 2.0 software analysis to find a reproducible model able to identify PVL in Staphylococcus aureus strains. Eighty-one S. aureus strains were used and tested for the presence of PVL, toxic shock syndrome toxin (TSST-1) and mecA genes. The peak at 4448 mass-to-charge ratio (m/z) was the most relevant peak to differentiate between PVL-producing and non-PVL-producing S. aureus. A model using only this peak had an overall recognition capability of 100% and an overall cross-validation of 77.07%. Prospective evaluation of the model allowed two cases of PVL-producing strains to be detected within a few minutes during the time of care and before polymerase chain reaction (PCR) results. Our study represents a proof of concept for the use of such rapid technology as a point-of-care method to identify potential lethal toxin quickly. We believe that such a rapid method will be timely to help change the therapeutic strategy and could be used in the future for other pathogens and infectious diseases.

Publication types

  • Evaluation Study

MeSH terms

  • Bacterial Toxins / analysis*
  • Exotoxins / analysis*
  • Humans
  • Leukocidins / analysis*
  • Sensitivity and Specificity
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / chemistry*
  • Staphylococcus aureus / isolation & purification
  • Time Factors
  • Virulence Factors / analysis*

Substances

  • Bacterial Toxins
  • Exotoxins
  • Leukocidins
  • Panton-Valentine leukocidin
  • Virulence Factors