title: MALDI-TOF mass spectrometry proteomic based identification of clinical bacterial isolates.
abstract: OBJECTIVE
  Pathogenic bacteria often cause life threatening infections especially in immunocompromised individuals. Therefore, rapid and reliable species identification is essential for a successful treatment and disease management. We evaluated a rapid, proteomic based technique for identification of clinical bacterial isolates by protein profiling using matrix-assisted laser desorption-ionization time - of - flight mass spectrometry (MALDI-TOF MS).
  
  
  METHODS
  Freshly grown bacterial isolates were selected from culture plates. Ethanol/formic acid extraction procedure was carried out, followed by charging of MALDI target plate with the extract and overlaying with α-cyano-4 hydroxy-cinnamic acid matrix solution. Identification was performed using the MALDI BioTyper 1.1, software for microbial identification (Bruker Daltonik GmbH, Bremen, Germany).
  
  
  RESULTS
  A comparative analysis of 82 clinical bacterial isolates using MALDI -TOF MS and conventional techniques was carried out. Amongst the clinical isolates, the accuracy at the species level for clinical isolates was 98.78%. One out of 82 isolates was not in accordance with the conventional assays because MALDI-TOF MS established it as Streptococcus pneumoniae and conventional methods as Streptococcus viridans.
  
  
  CONCLUSIONS
  MALDI - TOF MS was found to be an accurate, rapid, cost-effective and robust system for identification of clinical bacterial isolates. This innovative approach holds promise for earlier therapeutic intervention leading to better patient care.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Panda
authors.forename: Sravya
authors.initials: S
authors.lastname: Kurapati
authors.affiliation: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Jyotish C
authors.initials: JC
authors.lastname: Samantaray
authors.forename: Alagiri
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Shehla
authors.initials: S
authors.lastname: Khalil
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D001424:Bacterial Infections / Q000235:genetics* / Q000382:microbiology; D006801:Humans; D040901:Proteomics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D012336:RNA, Ribosomal, 16S