title: The Clinical Impact of Rapid, Direct MALDI-ToF Identification of Bacteria from Positive Blood Cultures.
abstract: BACKGROUND
  Faster identification of bacterial isolates from blood cultures can enable earlier clinical intervention for patients with sepsis. We evaluated the clinical impact of direct identification of micro-organisms from positive blood cultures using MALDI-ToF.
  
  
  METHODS
  Positive blood cultures with organisms seen on Gram stain were included over a four week period. For each patient case, comparison was made between the clinical advice given on day one with only a Gram stain result, and the follow up advice given on day two with the benefit of organism identification. Culture results were then compared with direct MALDI-ToF identification.
  
  
  RESULTS
  For 73 of 115 cases (63.5%), direct organism identification was obtained by MALDI-ToF. Of those 73, 70 (95.5%) had a result concordant with that of the plate culture. In 28 of the 115 cases (24.3%) direct MALDI-ToF identification on day one would have had a clear clinical benefit. In 11 cases it would have helped to identify the potential source of bacteraemia. In 11 cases it would have indicated a different antibiotic regimen on day one, with five patients receiving appropriate antibiotics 24 hours earlier. For 14 cases the blood culture isolate could have been designated as unlikely to be clinically significant.
  
  
  CONCLUSIONS
  We have demonstrated that organism identification on day one of blood culture positivity can have a direct clinical impact. Faster identification using MALDI-ToF assists the clinician in assessing the significance of a blood culture isolate on day one. It can allow earlier appropriate choice of antimicrobial agent, even in the absence of susceptibility testing, and help narrow down the potential source of infection providing a focus for further investigation in a more timely way than conventional techniques alone.
authors.affiliation: Public Health England, Public Health Laboratory Birmingham, Heart of England NHS Foundation Trust, Birmingham, United Kingdom.
authors.forename: Kathryn
authors.initials: K
authors.lastname: French
authors.affiliation: Public Health England, Public Health Laboratory Birmingham, Heart of England NHS Foundation Trust, Birmingham, United Kingdom.
authors.forename: Jason
authors.initials: J
authors.lastname: Evans
authors.affiliation: Public Health England, Public Health Laboratory Birmingham, Heart of England NHS Foundation Trust, Birmingham, United Kingdom.
authors.forename: Hannah
authors.identifier: http://orcid.org/0000-0003-3378-3219
authors.initials: H
authors.lastname: Tanner
authors.affiliation: Public Health England, Public Health Laboratory Birmingham, Heart of England NHS Foundation Trust, Birmingham, United Kingdom.
authors.forename: Savita
authors.initials: S
authors.lastname: Gossain
authors.affiliation: Public Health England, Public Health Laboratory Birmingham, Heart of England NHS Foundation Trust, Birmingham, United Kingdom.
authors.forename: Abid
authors.initials: A
authors.lastname: Hussain
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000175:diagnosis* / Q000188:drug therapy / Q000382:microbiology; D001419:Bacteria / Q000145:classification* / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D000071997:Blood Culture / Q000379:methods*; D005840:Gentian Violet; D006801:Humans; D010619:Phenazines; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents; C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet