The construction and evaluation of reference spectra for the identification of human pathogenic microorganisms by MALDI-TOF MS

PLoS One. 2014 Sep 2;9(9):e106312. doi: 10.1371/journal.pone.0106312. eCollection 2014.

Abstract

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an emerging technique for the rapid and high-throughput identification of microorganisms. There remains a dearth of studies in which a large number of pathogenic microorganisms from a particular country or region are utilized for systematic analyses. In this study, peptide mass reference spectra (PMRS) were constructed and evaluated from numerous human pathogens (a total of 1019 strains from 94 species), including enteric (46 species), respiratory (21 species), zoonotic (17 species), and nosocomial pathogens (10 species), using a MALDI-TOF MS Biotyper system (MBS). The PMRS for 380 strains of 52 species were new contributions to the original reference database (ORD). Compared with the ORD, the new reference database (NRD) allowed for 28.2% (from 71.5% to 99.7%) and 42.3% (from 51.3% to 93.6%) improvements in identification at the genus and species levels, respectively. Misidentification rates were 91.7% and 57.1% lower with the NRD than with the ORD for genus and species identification, respectively. Eight genera and 25 species were misidentified. For genera and species that are challenging to accurately identify, identification results must be manually determined and adjusted in accordance with the database parameters. Through augmentation, the MBS demonstrated a high identification accuracy and specificity for human pathogenic microorganisms. This study sought to provide theoretical guidance for using PMRS databases in various fields, such as clinical diagnosis and treatment, disease control, quality assurance, and food safety inspection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria / isolation & purification*
  • Databases, Protein
  • Fungi / isolation & purification*
  • Humans
  • Molecular Weight
  • Peptides / chemistry
  • Reference Standards
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Viruses / isolation & purification*

Substances

  • Peptides

Grants and funding

This work was supported by the national key program for infectious disease of China (Contract No. 2013ZX10004216-002), the national key scientific instrument and equipment development projects (Contract No. 2012YQ18011709), Mega Project of Research on HIV/AIDS, Viral Hepatitis Infectious Disease (Contract No. 2013ZX10004-101). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.