MALDI-TOF mass spectrometry provides high accuracy in identification of Salmonella at species level but is limited to type or subtype Salmonella serovars

Abstract

Salmonella can cause global foodborne illnesses in humans and many animals. The current diagnostic gold standard used for detecting Salmonella infection is microbiological culture followed by serological confirmation tests. However, these methods are complicated and time-consuming. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis offers some advantages in rapid identification, for example, simple and fast sample preparation, fast and automated measurement, and robust and reliable identification up to genus and species levels, possibly even to the strain level. In this study, we established a reference database for species identification using whole-cell MALDI-TOF MS; the database consisted of 12 obtained main spectra of the Salmonella culture collection strains belonged to seven serotypes. Eighty-two clinical isolates of Salmonella were identified using established database, and partial 16S rDNA gene sequencing and serological method were used as comparison. We found that MALDI-TOF mass spectrometry provided high accuracy in identification of Salmonella at species level but was limited to type or subtype Salmonella serovars. We also tried to find serovar-specific biomarkers and failed. Our study demonstrated that (a) MALDI-TOF MS was suitable for identification of Salmonella at species level with high accuracy and (b) that MALDI-TOF MS method presented in this study was not useful for serovar assignment of Salmonella currently, because of its low matching with serological method and (c) MALDI-TOF MS method presented in this study was not suitable to subtype S. typhimurium because of its low discriminatory ability.

Keywords

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry database identification subtyping

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References

Ngoi

Teh

Chai

. Overview of molecular typing tools for the characterization of Salmonella enterica in Malaysia. Biomed Environ Sci 2015; 28: 751–764.

Wattiau

Boland

Bertrand

. Methodologies for Salmonella enterica subsp. enterica subtyping: gold standards and alternatives. Appl Environ Microbiol 2011; 77: 7877–7885.

Majowicz

Musto

Scallan

. The global burden of nontyphoidal Salmonella gastroenteritis. Clin Infect Dis 2010; 50: 882–889.

Stewart

Reineke

Tortorello

. Comparison of assurance gold salmonella EIA, BAX for screening/Salmonella, and GENE-TRAK Salmonella DLP rapid assays for detection of Salmonella in alfalfa sprouts and sprout irrigation water. J AOAC Int 2002; 85: 395–403.

Zhao

. Rapid detection of six common Chinese G6PD mutations by MALDI-TOF MS. Blood Cells Mol Dis 2004; 32: 315–318.

Muldoon

Teaney

. Bacteriophage-based enrichment coupled to immunochromatographic strip-based detection for the determination of Salmonella in meat and poultry. J Food Prot 2007; 70: 2235–2242.

Amavisit

Browning

Lightfoot

. Rapid PCR detection of Salmonella in horse faecal samples. Vet Microbiol 2001; 79: 63–74.

Kurowski

Traub-Dargatz

Morley

. Detection of Salmonella spp in fecal specimens by use of real-time polymerase chain reaction assay. Am J Vet Res 2002; 63: 1265–1268.

Jackson

Edwards-Jones

Sutton

. Optimisation of intact cell MALDI method for fingerprinting of methicillin-resistant Staphylococcus aureus. J Microbiol Methods 2005; 62: 273–284.

10.

Fenselau

Demirev

. Characterization of intact microorganisms by MALDI mass spectrometry. Mass Spectrom Rev 2001; 20: 157–171.

11.

Demirev

Lin

Pineda

. Bioinformatics and mass spectrometry for microorganism identification: proteome-wide post-translational modifications and database search algorithms for characterization of intact H. pylori. Anal Chem 2001; 73: 4566–4573.

12.

Dieckmann

Helmuth

Erhard

. Rapid classification and identification of salmonellae at the species and subspecies levels by whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry. Appl Environ Microbiol 2008; 74: 7767–7778.

13.

Loff

Mare

de Kwaadsteniet

. 3M Molecular detection system versus MALDI-TOF mass spectrometry and molecular techniques for the identification of Escherichia coli 0157:H7, Salmonella spp. & Listeria spp. J Microbiol Methods 2014; 101: 33–43.

14.

Kuhns

Zautner

Rabsch

. Rapid discrimination of Salmonella enterica serovar Typhi from other serovars by MALDI-TOF mass spectrometry. PLoS One 2012; 7: e40004.

15.

Dieckmann

Malorny

. Rapid screening of epidemiologically important Salmonella enterica subsp. enterica serovars by whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry. Appl Environ Microbiol 2011; 77: 4136–4146.

16.

Ueda

Tanaka

Nagasawa

. Development of a novel matrix-assisted laser desorption/ionization time-of-flight mass spectrum (MALDI-TOF-MS)-based typing method to identify meticillin-resistant Staphylococcus aureus clones. J Hosp Infect 2015; 90: 147–155.

17.

Rettinger

Krupka

Grunwald

. Leptospira spp. strain identification by MALDI TOF MS is an equivalent tool to 16S rRNA gene sequencing and multi locus sequence typing (MLST). BMC Microbiol 2012; 12: 185.

18.

Jadhav

Gulati

Fox

. Rapid identification and source-tracking of Listeria monocytogenes using MALDI-TOF mass spectrometry. Int J Food Microbiol 2015; 202: 1–9.

19.

Grimont PAD and Weill F-X. Antigenic formulae of the Salmonella serovars. Paris, France: WHO Collaborating Centre for Reference and Research on Salmonella, Institut Pasteur, 2007.

20.

Guibourdenche

Roggentin

Mikoleit

. Supplement 2003-2007 (No. 47) to the White-Kauffmann-Le Minor scheme. Res Microbiol 2010; 161: 26–29.

21.

Freiwald

Sauer

. Phylogenetic classification and identification of bacteria by mass spectrometry. Nat Protoc 2009; 4: 732–742.

22.

Bosshard

Abels

Zbinden

. Ribosomal DNA sequencing for identification of aerobic gram-positive rods in the clinical laboratory (an 18-month evaluation). J Clin Microbiol 2003; 41: 4134–4140.

23.

Hunter

. Reproducibility and indices of discriminatory power of microbial typing methods. J Clin Microbiol 1990; 28: 1903–1905.

24.

Bader

. MALDI-TOF-MS-based species identification and typing approaches in medical mycology. Proteomics 2013; 13: 788–799.

25.

Egli

Tschudin-Sutter

Oberle

. Matrix-assisted laser desorption/ionization time of flight mass-spectrometry (MALDI-TOF MS) based typing of extended-spectrum beta-lactamase producing E. coli–a novel tool for real-time outbreak investigation. PLoS One 2015; 10: e0120624.

26.

Choi

Kim

Lee

. Proteome analysis of light-induced proteins in Synechocystis sp. PCC 6803: identification of proteins separated by 2D-PAGE using N-terminal sequencing and MALDI-TOF MS. Mol Cells 2000; 10: 705–711.

27.

Leuschner

Beresford-Jones

Robinson

. Difference and consensus of whole cell Salmonella enterica subsp. enterica serovars matrix-assisted laser desorption/ionization time-of-flight mass spectrometry spectra. Lett Appl Microbiol 2004; 38: 24–31.

28.

Sivapalasingam

Barrett

Kimura

. A multistate outbreak of Salmonella enterica Serotype Newport infection linked to mango consumption: impact of water-dip disinfestation technology. Clin Infect Dis 2003; 37: 1585–1590.

29.

Dionisi

Carattoli

Luzzi

. Molecular genotyping of Salmonella enterica Abortusovis by pulsed field gel electrophoresis. Vet Microbiol 2006; 116: 217–223.