title: Rapid identification of Gram-negative organisms from blood culture bottles using a modified extraction method and MALDI-TOF mass spectrometry.
abstract: The application of matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry (MS) directly to blood culture broth has potential to identify bloodstream infection earlier and facilitate timely management. We prospectively tested a novel, rapid, and inexpensive in-house spin-lysis protocol with formic acid extraction and compared MALDI-TOF MS identification of Gram-negative bacteria with traditional phenotypic methods (Phoenix™) directly from 318 BACTEC™ (Becton Dickinson, Franklin Lakes, USA) blood cultures. The MS score was ≥1.7 in 268 (91.8%) monomicrobial broths, with concordance to genus and species level of 100% and 97.0%, respectively. MALDI-TOF MS still has limited capacity to detect all species in polymicrobial broths.
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, New South Wales, Australia. Electronic address: tim.gray@tpg.com.au.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Gray
authors.forename: Lee
authors.initials: L
authors.lastname: Thomas
authors.forename: Tom
authors.initials: T
authors.lastname: Olma
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Iredell
authors.forename: Sharon C-A
authors.initials: SC
authors.lastname: Chen
mesh_terms: D016470:Bacteremia / Q000175:diagnosis / Q000382:microbiology*; D001431:Bacteriological Techniques / Q000379:methods*; D006090:Gram-Negative Bacteria / Q000145:classification* / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis / Q000382:microbiology*; D006801:Humans; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
keywords: Blood culture; Bloodstream infection; Gram negative bacilli; MALDI-TOF; Mass-spectrometry