title: Direct identification of bacteria from positive BacT/ALERT blood culture bottles using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry.
abstract: Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry is a fast and robust method for the identification of bacteria. In this study, we evaluate the performance of a laboratory-developed lysis method (LDT) for the rapid identification of bacteria from positive BacT/ALERT blood culture bottles. Of the 168 positive bottles tested, 159 were monomicrobial, the majority of which were Gram-positive organisms (61.0% versus 39.0%). Using a cut-off score of ≥1.7, 80.4% of the organisms were correctly identified to the species level, and the identification rate of Gram-negative organisms (90.3%) was found to be significantly greater than that of Gram-positive organisms (78.4%). The simplicity and cost-effectiveness of the LDT enable it to be fully integrated into the routine workflow of the clinical microbiology laboratory, allowing for rapid identification of Gram-positive and Gram-negative bacteria within an hour of blood culture positivity.
authors.affiliation: Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, CA, USA.
authors.forename: Javier
authors.initials: J
authors.lastname: Mestas
authors.affiliation: Division of Infectious Diseases, Department of Pediatrics, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA.
authors.forename: Susanna
authors.initials: S
authors.lastname: Felsenstein
authors.affiliation: Department of Pathology and Laboratory Medicine, Keck School of Medicine, University of Southern California and Children's Hospital Los Angeles, Los Angeles, CA, USA. Electronic address: jdienbard@chla.usc.edu.
authors.forename: Jennifer Dien
authors.initials: JD
authors.lastname: Bard
mesh_terms: D016470:Bacteremia / Q000175:diagnosis*; D001419:Bacteria / Q000737:chemistry / Q000145:classification* / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D001769:Blood / Q000382:microbiology*; D006801:Humans; D012680:Sensitivity and Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors
keywords: Bacteria; Blood culture bottles; Identification; MALDI-TOF