title: Rapid species specific identification and subtyping of Yersinia enterocolitica by MALDI-TOF mass spectrometry.
abstract: Yersinia enterocolitica are Gram-negative pathogens and known as important causes of foodborne infections. Rapid and reliable identification of strains of the species Y. enterocolitica within the genus Yersinia and the differentiation of the pathogenic from the non-pathogenic biotypes has become increasingly important. We evaluated here the application of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid species identification and subtyping of Y. enterocolitica. To this end, we developed a reference MS database library including 19 Y. enterocolitica (non-pathogenic biotype 1A and pathogenic biotypes 2 and 4) as well as 24 non-Y. enterocolitica strains, belonging to eleven different other Yersinia spp. The strains provided reproducible and unique mass spectra profiles covering a wide molecular mass range (2000 to 30,000 Da). Species-specific and biotype-specific biomarker protein mass patterns were determined for Y. enterocolitica. The defined biomarker mass patterns (SARAMIS SuperSpectrum™) were validated using 117 strains from various Y. enterocolitica bioserotypes in a blind-test. All strains were correctly identified and for all strains the mass spectrometry-based identification scheme yielded identical results compared to a characterization by a combination of biotyping and serotyping. Our study demonstrates that MALDI-TOF-MS is a reliable and powerful tool for the rapid identification of Y. enterocolitica strains to the species level and allows subtyping of strains to the biotype level.
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Zurich, Switzerland. stephanr@fsafety.uzh.ch
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.forename: Nicole
authors.initials: N
authors.lastname: Cernela
authors.forename: Dominik
authors.initials: D
authors.lastname: Ziegler
authors.forename: Valentin
authors.initials: V
authors.lastname: Pflüger
authors.forename: Mauro
authors.initials: M
authors.lastname: Tonolla
authors.forename: Damiana
authors.initials: D
authors.lastname: Ravasi
authors.forename: Maria
authors.initials: M
authors.lastname: Fredriksson-Ahomaa
authors.forename: Herbert
authors.initials: H
authors.lastname: Hächler
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry; D015373:Bacterial Typing Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D015009:Yersinia Infections / Q000175:diagnosis / Q000382:microbiology*; D015008:Yersinia enterocolitica / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification*
chemical_list: D001426:Bacterial Proteins