title: [EXPRESS IDENTIFICATION OF POSITIVE BLOOD CULTURES USING DIRECT MALDI-TOF MASS SPECTROMETRY].
abstract: OBJECTIVE
  To evaluate the effectiveness of direct identification of pathogens of bacteremia by direct matrix assisted laser desorption ionization time-flight mass spectrometry (mALDI-TOF) compared to routine method.
  
  
  METHODS
  A prospective study included 211 positive blood cultures obtained from 116 patients (106 adults and 10 children, aged from 2 weeks to 77 years old in the ICU after open heart surgery. Incubation was carried out under aerobic vials with a sorbent for antibiotics Analyzer BacT/ALERT 3D 120 (bioMerieux, France) in parallel with the primary sieving blood cultures on solid nutrient media with subsequent identification of pure cultures using MALDI-TOF mass spectrometry analyzer Vitek MS, bioMerieux, France routine method), after appropriate sample preparation we carried out a direct (without screening) MALDI-TOF mass spectrometric study of monocomponental blood cultures (n = 201).
  
  
  RESULTS
  using a routine method in 211 positive blood cultures we identified 23 types of microorganisms (Staphylococcus (n = 87), Enterobacteria- ceae (n = 71), Enterococci (n = 20), non-fermentative Gram-negative bacteria (n = 18), others (n = 5). The average time of incubation of samples to obtain a signal of a blood culture growth was 16.2 ± 7.4 h (from 3.75 to 51 hours.) During the first 12 hours of incubation, growth was obtained in 32.4% of the samples, and on the first day in 92.2%. In the direct mass spectrometric analysis mnonocomponental blood cultures (n = 201) is well defined up to 153 species of the sample (76.1%), while the share of successful identification of Gram-negative bacteria was higher than that of Gram-positive (85.4 and 69, 1%, respectively p = 0.01). The high degree of consistency in the results of standard and direct method of identifying blood cultures using MALDI-TOF mass spectrometry (κ = 0.96, p < 0.001; the samples included in the calculation for which both option given result). Duration of the direct mass spectrometric analysis, including sample preparation, was no longer than 1 hour:
  
  
  CONCLUSIONS
  The method of direct MALDI-TOF mass spectrometry allows to significantly speed up the identification of blood cultures that may contribute as much as possible early appointment effective regimes of starting antibiotic therapy.
authors: D A
authors: DA
authors: Popov
authors: S T
authors: ST
authors: Ovseenko
authors: T Yu
authors: TY
authors: Vostrikova
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016470:Bacteremia / Q000382:microbiology*; D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D055815:Young Adult