title: Comparison of the Bruker MALDI-TOF mass spectrometry system and conventional phenotypic methods for identification of Gram-positive rods.
abstract: In recent years, MALDI-TOF Mass Spectrometry (MS) method has emerged as a promising and a reliable tool for bacteria identification. In this study we compared Bruker MALDI-TOF MS and conventional phenotypic methods to identify a collection of 333 Gram-positive clinical isolates comprising 22 genera and 60 species. 16S rRNA sequencing was the reference molecular technique, and rpoB gene sequecing was used as a secondary gene target when 16Sr RNA did not allow species identification of Corynebacterium spp. We also investigate if score cut-offs values of ≥ 1,5 and ≥ 1,7 were accurate for genus and species-level identification using the Bruker system. Identification at species level was obtained for 92,49% of Gram-positive rods by MALDI-TOF MS compared to 85,89% by phenotypic method. Our data validates the score ≥ 1,5 for genus level and ≥ 1,7 for species-level identification in a large and diverse collection of Gram-positive rods. The present study has proved the accuracy of MALDI-TOF MS as an identification method in Gram-positive rods compared to currently used methods in routine laboratories.
authors.affiliation: Instituto de Fisiopatología y Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Claudia
authors.initials: C
authors.lastname: Barberis
authors.affiliation: Instituto de Fisiopatología y Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Marisa
authors.initials: M
authors.lastname: Almuzara
authors.affiliation: Université Paris Descartes, Paris, France; Laboratoire de Microbiologie, Hopital Necker-Enfants malades, Paris, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Join-Lambert
authors.affiliation: Instituto de Microbiología y Parasitología Médica, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: María Soledad
authors.initials: MS
authors.lastname: Ramírez
authors.affiliation: Instituto de Fisiopatología y Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Angela
authors.initials: A
authors.lastname: Famiglietti
authors.affiliation: Instituto de Fisiopatología y Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Vay
mesh_terms: D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D006094:Gram-Positive Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S