title: Evaluation of the Biotyper MALDI-TOF MS system for identification of Staphylococcus species.
abstract: The Bruker Biotyper MALDI-TOF MS (Biotyper) system, with a modified 30 minute formic acid extraction method, was evaluated by its ability to identify 216 clinical Staphylococcus isolates from the CDC reference collection comprising 23 species previously identified by conventional biochemical tests. 16S rDNA sequence analysis was used to resolve discrepancies. Of these, 209 (96.8%) isolates were correctly identified: 177 (84.7%) isolates had scores ≥2.0, while 32 (15.3%) had scores between 1.70 and 1.99. The Biotyper identification was inconsistent with the biochemical identification for seven (3.2%) isolates, but the Biotyper identifications were confirmed by 16S rDNA analysis. The distribution of low scores was strongly species-dependent, e.g. only 5% of Staphylococcus epidermidis and 4.8% of Staphylococcus aureus isolates scored below 2.0, while 100% of Staphylococcus cohnii, 75% of Staphylococcus sciuri, and 60% of Staphylococcus caprae produced low but accurate Biotyper scores. Our results demonstrate that the Biotyper can reliably identify Staphylococcus species with greater accuracy than conventional biochemicals. Broadening of the reference database by inclusion of additional examples of under-represented species could further optimize Biotyper results.
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States. Electronic address: waz7@cdc.gov.
authors.forename: Wenming
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Sieradzki
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Valerie
authors.initials: V
authors.lastname: Albrecht
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Sigrid
authors.initials: S
authors.lastname: McAllister
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Wen
authors.initials: W
authors.lastname: Lin
authors.affiliation: Division of Scientific Resources, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Olga
authors.initials: O
authors.lastname: Stuchlik
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Brandi
authors.initials: B
authors.lastname: Limbago
authors.affiliation: Division of Scientific Resources, Centers for Disease Control and Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: Jan
authors.initials: J
authors.lastname: Pohl
authors.affiliation: Division of Healthcare Quality Promotion, Centers for Disease Control Prevention, 1600 Clifton Rd NE, Atlanta, GA, United States.
authors.forename: J
authors.initials: J
authors.lastname: Kamile Rasheed
mesh_terms: D058889:Molecular Typing / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013210:Staphylococcus / Q000737:chemistry* / Q000145:classification*
keywords: Biochemical identification; MALDI-TOF MS; Staphylococcus