title: Species identification within Acinetobacter calcoaceticus-baumannii complex using MALDI-TOF MS.
abstract: Acinetobacter baumannii, one of the more clinically relevant species in the Acinetobacter genus is well known to be multi-drug resistant and associated with bacteremia, urinary tract infection, pneumonia, wound infection and meningitis. However, it cannot be differentiated from closely related species such as Acinetobacter calcoaceticus, Acinetobacter pittii and Acinetobacter nosocomialis by most phenotypic tests and can only be differentiated by specific, time consuming genotypic tests with very limited use in clinical microbiological laboratories. As a result, these species are grouped into the A. calcoaceticus-A. baumannii (Acb) complex. Herein we investigated the mass spectra of 73 Acinetobacter spp., representing ten different species, using an AB SCIEX 5800 MALDI-TOF MS to differentiate members of the Acinetobacter genus, including the species of the Acb complex. RpoB gene sequencing, 16S rRNA sequencing, and gyrB multiplex PCR were also evaluated as orthogonal methods to identify the organisms used in this study. We found that whilst 16S rRNA and rpoB gene sequencing could not differentiate A. pittii or A. calcoaceticus, they can be differentiated using gyrB multiplex PCR and MALDI-TOF MS. All ten Acinetobacter species investigated could be differentiated by their MALDI-TOF mass spectra.
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: Benjamin E W
authors.initials: BE
authors.lastname: Toh
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: David L
authors.initials: DL
authors.lastname: Paterson
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: Witchuda
authors.initials: W
authors.lastname: Kamolvit
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia; King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; World Health Organization Collaborating Centre for Infection Prevention and Control, and Gulf Cooperation Council Center for Infection Control, Riyadh, Saudi Arabia.
authors.forename: Hosam
authors.initials: H
authors.lastname: Zowawi
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: David
authors.initials: D
authors.lastname: Kvaskoff
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sidjabat
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wailan
authors.affiliation: Department of Infectious Diseases, Alfred Hospital, Melbourne, Australia; Department of Microbiology, Monash University, Melbourne, Australia.
authors.forename: Anton Y
authors.initials: AY
authors.lastname: Peleg
authors.affiliation: The University of Queensland, UQ Centre for Clinical Research, Queensland, Royal Brisbane and Women's Hospital Campus, Brisbane, Australia. Electronic address: c.huber@uq.edu.au.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Huber
mesh_terms: D000150:Acinetobacter / Q000737:chemistry* / Q000145:classification / Q000302:isolation & purification*; D000151:Acinetobacter Infections / Q000175:diagnosis* / Q000382:microbiology*; D001431:Bacteriological Techniques / Q000379:methods*; D027081:DNA Gyrase / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012321:DNA-Directed RNA Polymerases; C105078:RNA polymerase beta subunit; D027081:DNA Gyrase
keywords: A. baumannii; Acb complex; Mass spectra; Rapid diagnostics