title: Rapid identification and typing of Yersinia pestis and other Yersinia species by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.
abstract: BACKGROUND
  Accurate identification is necessary to discriminate harmless environmental Yersinia species from the food-borne pathogens Yersinia enterocolitica and Yersinia pseudotuberculosis and from the group A bioterrorism plague agent Yersinia pestis. In order to circumvent the limitations of current phenotypic and PCR-based identification methods, we aimed to assess the usefulness of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) protein profiling for accurate and rapid identification of Yersinia species. As a first step, we built a database of 39 different Yersinia strains representing 12 different Yersinia species, including 13 Y. pestis isolates representative of the Antiqua, Medievalis and Orientalis biotypes. The organisms were deposited on the MALDI-TOF plate after appropriate ethanol-based inactivation, and a protein profile was obtained within 6 minutes for each of the Yersinia species.
  
  
  RESULTS
  When compared with a 3,025-profile database, every Yersinia species yielded a unique protein profile and was unambiguously identified. In the second step of analysis, environmental and clinical isolates of Y. pestis (n = 2) and Y. enterocolitica (n = 11) were compared to the database and correctly identified. In particular, Y. pestis was unambiguously identified at the species level, and MALDI-TOF was able to successfully differentiate the three biotypes.
  
  
  CONCLUSIONS
  These data indicate that MALDI-TOF can be used as a rapid and accurate first-line method for the identification of Yersinia isolates.
authors.affiliation: Unité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, UMR CNRS 6236-IRD 198, Faculté de Médecine, IFR48, Université de la Méditerranée, Marseille, France.
authors.forename: Saravanan
authors.initials: S
authors.lastname: Ayyadurai
authors.forename: Christophe
authors.initials: C
authors.lastname: Flaudrops
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Michel
authors.initials: M
authors.lastname: Drancourt
mesh_terms: D015373:Bacterial Typing Techniques / Q000379:methods*; D004783:Environmental Microbiology; D006801:Humans; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D015007:Yersinia / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D015009:Yersinia Infections / Q000382:microbiology; D015010:Yersinia pestis / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000302:isolation & purification