title: Rapid identification of gram negative bacteria from blood culture broth using MALDI-TOF mass spectrometry.
abstract: An important role of the clinical microbiology laboratory is to provide rapid identification of bacteria causing bloodstream infection. Traditional identification requires the sub-culture of signaled blood culture broth with identification available only after colonies on solid agar have matured. MALDI-TOF MS is a reliable, rapid method for identification of the majority of clinically relevant bacteria when applied to colonies on solid media. The application of MALDI-TOF MS directly to blood culture broth is an attractive approach as it has potential to accelerate species identification of bacteria and improve clinical management. However, an important problem to overcome is the pre-analysis removal of interfering resins, proteins and hemoglobin contained in blood culture specimens which, if not removed, interfere with the MS spectra and can result in insufficient or low discrimination identification scores. In addition it is necessary to concentrate bacteria to develop spectra of sufficient quality. The presented method describes the concentration, purification, and extraction of Gram negative bacteria allowing for the early identification of bacteria from a signaled blood culture broth.
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital; timgray000@gmail.com.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Gray
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital.
authors.forename: Lee
authors.initials: L
authors.lastname: Thomas
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital.
authors.forename: Tom
authors.initials: T
authors.lastname: Olma
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital.
authors.forename: David H
authors.initials: DH
authors.lastname: Mitchell
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital; Centre for Research Excellence in Critical Infection, Westmead Millennium Institute, Westmead Hospital; Sydney Emerging Infectious Diseases Institute, University of Sydney, Westmead Hospital.
authors.forename: Jon R
authors.initials: JR
authors.lastname: Iredell
authors.affiliation: Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, Westmead Hospital; Sydney Emerging Infectious Diseases Institute, University of Sydney, Westmead Hospital.
authors.forename: Sharon C A
authors.initials: SC
authors.lastname: Chen
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods*; D005561:Formates / Q000737:chemistry; D006090:Gram-Negative Bacteria / Q000302:isolation & purification*; D016905:Gram-Negative Bacterial Infections / Q000097:blood*; D006801:Humans; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D005561:Formates; C030544:formic acid