title: [MALDI-TOF MASS-SPECTROMETRIC ANAIYSIS OF LEPTOSPIRA SPP. USED IN SERODIAGNOSTICS OF LEPTOSPIROSIS].
abstract: OBJECTIVE
  Creation of a classification model of Leptospira spp. serovar model using ClinProTools 3.0 software and evaluation of use of MALDI-TOF MS as a method of quality control of reference strains of leptospira.
  
  
  METHODS
  10 reference strains of Leptospira spp. were used in the study according to microscopic agglutination reaction from the collection of Pasteur RIEM. All the strains were cultivated for 10 days in Terskikh medium at 28 degrees C. Cell extracts were obtained by ethanol/formic acid method. α-cyano-4-hydroxycinnamic acid solution was used as a matrix. Mass-spectra were obtained in Microflex mass-spectrometer (Bruker Daltonics, Germany). External validation of the test-model was carried out using novel spectra of every reference strain during their repeated reseeding.
  
  
  RESULTS
  Values of cross-validation and confirmatory ability of the optimal model, built on a genetic algorithm, was 99.14 and 100%, respectively. This model contained 11 biomarker peaks (m/z 2959, 3447, 3548, 3764, 3895, 5221, 5917, 6173, 6701, 7013, 8364) for serovar classification. Results of the external validation have shown a 100% correct classification in serovar classesin Sejroe, Ballum, Tarassovi; Copenhageni, Mozdoc, Grippotyphosa and Patoc, that indicates a high prognostic ability of the model in these classes. However, data from verification matrix have shown, that 50%.of the spectra from Canicola and Pomona serovars were classified as Patoc class, that could be associated with cross serological activity of Patoc serovar L. biflexa with pathogenic leptospirae.
  
  
  CONCLUSIONS
  MALDI-TOF mass-spectrometry method combined with building and using the classification model could be a useful instrument for intra-laboratory control of leptospira reseeding.
authors.forename: E V
authors.initials: EV
authors.lastname: Zyeva
authors.forename: N A
authors.initials: NA
authors.lastname: Stoyanova
authors.forename: N K
authors.initials: NK
authors.lastname: Tokarevich
authors.forename: Areg A
authors.initials: AA
authors.lastname: Totolyan
mesh_terms: D003373:Coumaric Acids / Q000737:chemistry*; D003470:Culture Media / Q000737:chemistry; D006801:Humans; D007919:Leptospira / Q000737:chemistry / Q000145:classification* / Q000254:growth & development / Q000378:metabolism; D010802:Phylogeny; D025341:Principal Component Analysis; D012703:Serotyping / Q000379:methods*; D012984:Software; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D003373:Coumaric Acids; D003470:Culture Media; C007175:alpha-cyano-4-hydroxycinnamate