title: MALDI-TOF-MS for rapid detection of staphylococcal Panton-Valentine leukocidin.
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.
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, CNRS-IRD, UMR 6236, Faculté de Médecine et de Pharmacie, Université de la Méditerranée, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France.
authors.forename: Fadi
authors.initials: F
authors.lastname: Bittar
authors.forename: Zoulikha
authors.initials: Z
authors.lastname: Ouchenane
authors.forename: Farida
authors.initials: F
authors.lastname: Smati
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Rolain
mesh_terms: D001427:Bacterial Toxins / Q000032:analysis*; D005098:Exotoxins / Q000032:analysis*; D006801:Humans; D007956:Leukocidins / Q000032:analysis*; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000302:isolation & purification; D013997:Time Factors; D037521:Virulence Factors / Q000032:analysis*
chemical_list: D001427:Bacterial Toxins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D037521:Virulence Factors