Impact of Rapid Organism Identification via Matrix-Assisted Laser desorption/ionization Time-Of-Flight Combined With Antimicrobial Stewardship Team Intervention in Adult Patients With Bacteremia and Candidemia

Clin Infect Dis. 2013 Nov;57(9):1237-45. doi: 10.1093/cid/cit498. Epub 2013 Jul 29.


Background: Integration of rapid diagnostic testing via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) with antimicrobial stewardship team (AST) intervention has the potential for early organism identification, customization of antibiotic therapy, and improvement in patient outcomes. The objective of this study was to assess the impact of this combined approach on clinical and antimicrobial therapy-related outcomes in patients with bloodstream infections.

Methods: A pre-post quasi-experimental study was conducted to analyze the impact of MALDI-TOF with AST intervention in patients with bloodstream infections. The AST provided evidence-based antibiotic recommendations after receiving real-time notification following blood culture Gram stain, organism identification, and antimicrobial susceptibilities. Outcomes were compared to a historic control group.

Results: A total of 501 patients with bacteremia or candidemia were included in the final analysis: 245 patients in the intervention group and 256 patients in the preintervention group. MALDI-TOF with AST intervention decreased time to organism identification (84.0 vs 55.9 hours, P < .001), and improved time to effective antibiotic therapy (30.1 vs 20.4 hours, P = .021) and optimal antibiotic therapy (90.3 vs 47.3 hours, P < .001). Mortality (20.3% vs 14.5%), length of intensive care unit stay (14.9 vs 8.3 days) and recurrent bacteremia (5.9% vs 2.0%) were lower in the intervention group on univariate analysis, and acceptance of an AST intervention was associated with a trend toward reduced mortality on multivariable analysis (odds ratio, 0.55, P = .075).

Conclusion: MALDI-TOF with AST intervention decreased time to organism identification and time to effective and optimal antibiotic therapy.

Keywords: MALDI-TOF; antimicrobial stewardship; bacteremia; candidemia.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / diagnosis*
  • Bacteremia / drug therapy
  • Bacteria / chemistry
  • Bacteria / classification
  • Bacteria / isolation & purification*
  • Candida / chemistry
  • Candida / classification
  • Candida / isolation & purification*
  • Candidemia / diagnosis*
  • Candidemia / drug therapy
  • Drug Prescriptions / standards
  • Drug Utilization / standards*
  • Female
  • Humans
  • Male
  • Microbiological Techniques / methods
  • Middle Aged
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Time Factors
  • Treatment Outcome


  • Anti-Bacterial Agents