The Construction and Evaluation of Reference Spectra for the Identification of Human Pathogenic Microorganisms by MALDI-TOF MS

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.

Evaluation of the Bruker Biotyper Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry System for Identification of Blood Isolates of Vibrio Species

“…Our previous study demonstrated that the Bruker Biotyper MALDI-TOF MS system, with implementation of a newly created database, can accurately identify other important human-enteropathogenic aeromonads, such as Aeromonas dhakensis, A. hydrophila, A. veronii, and A. caviae (17). However, few studies have investigated the ability of the Bruker Biotyper MALDI-TOF MS system to accurately identify pathogenic Vibrio species, particularly V. cholerae (10,(18)(19)(20). In the present study, we evaluated the ability of the Bruker Biotyper MALDI-TOF MS system to accurately identify genetically confirmed Vibrio species that were recovered from patients with bloodstream infections.…”

Recent Technology of Clinical Microbiology; Whole Genome Sequencing (WGS) and Matrix-Assisted, Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS)

“…VITEK MS (bioMérieux) and Biotyper (Bruker Daltonics) are examples of commercially available MALDI-TOF systems [7,8]. A recent report revealed that the MALDI-TOF assay had high correspondence with a biochemical culture and test (44), and MALDI-TOF and 16S rDNA analysis also had high correspondence, proving that MALDI-TOF is a rapid and accurate method [44,45].…”

“…Its advantage includes high sensitivity, tolerance to buffers, fast data acquisition, and simple and robust instrumentation. MALDI-TOF was first used for bacterial identification 10 years ago, and nearly all identification in North America and Europe is now carried out using the technique [7,8].…”

Advantage of MALDI ‐ TOF ‐ MS over biochemical‐based phenotyping for microbial identification illustrated on industrial applications

“…All identification methods rely on the quality of the underlying database, and perform very well on bacteria studied from a medical application background (Xiao et al . ).…”

“…Since sequencing remains laborious and time consuming, faster identification systems have been developed designed for medical purposes. All identification methods rely on the quality of the underlying database, and perform very well on bacteria studied from a medical application background (Xiao et al 2014).…”