title: Comparison of three preparatory methods for detection of bacteremia by MALDI-TOF mass spectrometry.
abstract: We evaluated 3 preparatory methods for processing positive blood culture bottle broths prior to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis-differential centrifugation, 10% sodium dodecyl sulfate (SDS), and the Sepsityper kit. Initial evaluation used genus and species level cutoff scores of 1.700-1.999 and ≥ 2.000, respectively. Processing of an initial 79 blood bottle cultures by differential centrifugation yielded correct identifications of 51 (65%) to the genus and 34 (43%) to the species levels. One hundred and one different blood bottles were simultaneously processed with 10% SDS and Sepsityper. Both yielded genus-level identifications for 77 (76%), and the 2 yielded species-level identifications for 49 (49%) and 54 (54%) of bottles, respectively. Adjustment of the score cutoff criteria for genus (1.500-1.699) and species (≥ 1.700) improved identification percentages, particularly for species-level identifications (P < 0.05).
authors.affiliation: Division of Clinical Microbiology, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Ryan T
authors.initials: RT
authors.lastname: Saffert
authors.forename: Scott A
authors.initials: SA
authors.lastname: Cunningham
authors.forename: Jayawant
authors.initials: J
authors.lastname: Mandrekar
authors.forename: Robin
authors.initials: R
authors.lastname: Patel
mesh_terms: D016470:Bacteremia / Q000175:diagnosis* / Q000382:microbiology*; D001419:Bacteria / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification*; D001431:Bacteriological Techniques / Q000379:methods*; D001769:Blood / Q000382:microbiology; D002498:Centrifugation / Q000379:methods; D006801:Humans; D013048:Specimen Handling / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*