Matrix-assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) Can Precisely Discriminate the Lineages of Listeria monocytogenes and Species of Listeria

Abstract

The genetic lineages of Listeria monocytogenes and other species of the genus Listeria are correlated with pathogenesis in humans. Although matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has become a prevailing tool for rapid and reliable microbial identification, the precise discrimination of Listeria species and lineages remains a crucial issue in clinical settings and for food safety. In this study, we constructed an accurate and reliable MS database to discriminate the lineages of L. monocytogenes and the species of Listeria (L. monocytogenes, L. innocua, L. welshimeri, L. seeligeri, L. ivanovii, L. grayi, and L. rocourtiae) based on the S10-spc-alpha operon gene encoded ribosomal protein mass spectrum (S10-GERMS) proteotyping method, which relies on both genetic information (genomics) and observed MS peaks in MALDI-TOF MS (proteomics). The specific set of eight biomarkers (ribosomal proteins L24, L6, L18, L15, S11, S9, L31 type B, and S16) yielded characteristic MS patterns for the lineages of L. monocytogenes and the different species of Listeria, and led to the construction of a MS database that was successful in discriminating between these organisms in MALDI-TOF MS fingerprinting analysis followed by advanced proteotyping software Strain Solution analysis. We also confirmed the constructed database on the proteotyping software Strain Solution by using 23 Listeria strains collected from natural sources.

Evaluation of repetitive-PCR and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid strain typing of Bacillus coagulans

“…Strain typing using mass spectra by MALDI-TOF MS has already been proposed in the S10-GERMS (S10-spc-alpha operon gene encoded ribosomal protein mass spectrum) method [ 31 – 34 ]. The S10-GERMS method is focused on the S10-spc-alpha operon, where at least half of all ribosomal proteins are encoded.…”

Biosensor for the detection of Listeria monocytogenes: emerging trends

“…However, these do not offer the insight for complexities of the pathogen at the molecular level. Many omics approaches have been used for the detection of pathogenic and non-pathogenic L. monocytogenes (Singh et al, 2011;Beale et al, 2014;Tatituri et al, 2015;Jadhav et al, 2015;Ojima-Kato et al, 2016;Martinović et al, 2016;Cheng et al, 2016). These observations provide information related to pathogen's ability to overcome a diverse range of environmental regimes (e.g., salt concentrations, pH, temperature, etc.…”

Molecular typing of bacteria for epidemiological surveillance and outbreak investigation / Molekulare Typisierung von Bakterien für die epidemiologische Überwachung und Ausbruchsabklärung

“…In general, public databases such as Basic Local Alignment Search Tool (BLAST) or the RDP yield better identification results for rare or highly pathogenic bacteria than quality-controlled databases such as RIDOM or MicroSeq 500 (Ruppitsch et al, 2007b). A drawback of 16S-rDNA-based identification is the inability to differentiate some closely related species within the genera Brucella (Gee et al, 2004), Bacillus, Yersinia (Ruppitsch et al, 2007b;Almeida and Araujo 2013), Shigella (Thiem et al, 2004), Listeria (Ojima-Kato et al, 2016), and the Mycobacteria tuberculosis complex (Jung et al, 2016). Members of these pathogen groups must be identified by applying additional species-specific assays (Winchell et al, 2010;Shallom et al, 2011;Antolinos et al, 2012;Stöckel et al, 2012).…”