Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry

<i>Escherichia coli</i> and <i>Shigella flexneri</i> are challenging to differentiate using methods such as phenotyping, 16S rRNA sequencing, or protein profiling through matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) due to their close relatedness....

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Main Author: Adrian Arendowski
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Pathogens
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Online Access:https://www.mdpi.com/2076-0817/14/1/19
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author Adrian Arendowski
author_facet Adrian Arendowski
author_sort Adrian Arendowski
collection DOAJ
description <i>Escherichia coli</i> and <i>Shigella flexneri</i> are challenging to differentiate using methods such as phenotyping, 16S rRNA sequencing, or protein profiling through matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) due to their close relatedness. This study explores the potential for identifying <i>E. coli</i> and <i>S. flexneri</i> by incorporating reference spectra of metabolite profiles, obtained via surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) employing gold nanoparticles (AuNPs), into the Bruker Biotyper database. Metabolite extracts from <i>E. coli</i> and <i>S. flexneri</i> cells were prepared using liquid–liquid extraction in a chloroform–methanol–water system. The extracts were analyzed using Au-SALDI MS in positive ion mode, and reference spectra, compiled from 30 spectra for each bacterium, were added to the database. Identification of bacteria based on metabolite fingerprints in the Biotyper database produced correct results with scores exceeding 2.75. The results of Partial Least Squares-Discriminant Analysis (PLS-DA) demonstrated that the metabolomic approach could accurately differentiate the microorganisms under study. A panel of nine <i>m</i>/<i>z</i> values was also identified, each with an area under the ROC curve of above 0.8, enabling accurate identification of <i>E. coli</i> and <i>S. flexneri</i>. A search of metabolite databases allowed the following compounds to be assigned to the selected <i>m</i>/<i>z</i> values: <i>N</i>-acetylputrescine, arginine, 2-maleylacetate, benzoyl phosphate, <i>N</i>8-acetylspermidine, alanyl-glutamate, 4-hydroxy-2,3,4,5-tetrahydrodipicolinate, and sucrose. The analyses showed that identification of bacteria based on metabolite profiles obtained by the Au-SALDI MS method is feasible and can be useful for distinguishing closely related microorganisms that are difficult to differentiate by other techniques.
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spelling doaj-art-7cfa171f72b0436e9dbefcf6c73d190a2025-01-24T13:44:37ZengMDPI AGPathogens2076-08172024-12-011411910.3390/pathogens14010019Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass SpectrometryAdrian Arendowski0Department of Inorganic and Analytical Chemistry, Faculty of Chemistry, Rzeszów University of Technology, Powstańców Warszawy 6, 35-959 Rzeszów, Poland<i>Escherichia coli</i> and <i>Shigella flexneri</i> are challenging to differentiate using methods such as phenotyping, 16S rRNA sequencing, or protein profiling through matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) due to their close relatedness. This study explores the potential for identifying <i>E. coli</i> and <i>S. flexneri</i> by incorporating reference spectra of metabolite profiles, obtained via surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) employing gold nanoparticles (AuNPs), into the Bruker Biotyper database. Metabolite extracts from <i>E. coli</i> and <i>S. flexneri</i> cells were prepared using liquid–liquid extraction in a chloroform–methanol–water system. The extracts were analyzed using Au-SALDI MS in positive ion mode, and reference spectra, compiled from 30 spectra for each bacterium, were added to the database. Identification of bacteria based on metabolite fingerprints in the Biotyper database produced correct results with scores exceeding 2.75. The results of Partial Least Squares-Discriminant Analysis (PLS-DA) demonstrated that the metabolomic approach could accurately differentiate the microorganisms under study. A panel of nine <i>m</i>/<i>z</i> values was also identified, each with an area under the ROC curve of above 0.8, enabling accurate identification of <i>E. coli</i> and <i>S. flexneri</i>. A search of metabolite databases allowed the following compounds to be assigned to the selected <i>m</i>/<i>z</i> values: <i>N</i>-acetylputrescine, arginine, 2-maleylacetate, benzoyl phosphate, <i>N</i>8-acetylspermidine, alanyl-glutamate, 4-hydroxy-2,3,4,5-tetrahydrodipicolinate, and sucrose. The analyses showed that identification of bacteria based on metabolite profiles obtained by the Au-SALDI MS method is feasible and can be useful for distinguishing closely related microorganisms that are difficult to differentiate by other techniques.https://www.mdpi.com/2076-0817/14/1/19gold nanoparticlesidentificationmass spectrometrymetabolitesmicroorganismssurface-assisted laser desorption/ionization
spellingShingle Adrian Arendowski
Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
Pathogens
gold nanoparticles
identification
mass spectrometry
metabolites
microorganisms
surface-assisted laser desorption/ionization
title Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
title_full Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
title_fullStr Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
title_full_unstemmed Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
title_short Differentiation of <i>Escherichia coli</i> and <i>Shigella flexneri</i> by Metabolite Profiles Obtained Using Gold Nanoparticles-Based Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
title_sort differentiation of i escherichia coli i and i shigella flexneri i by metabolite profiles obtained using gold nanoparticles based surface assisted laser desorption ionization mass spectrometry
topic gold nanoparticles
identification
mass spectrometry
metabolites
microorganisms
surface-assisted laser desorption/ionization
url https://www.mdpi.com/2076-0817/14/1/19
work_keys_str_mv AT adrianarendowski differentiationofiescherichiacoliiandishigellaflexneriibymetaboliteprofilesobtainedusinggoldnanoparticlesbasedsurfaceassistedlaserdesorptionionizationmassspectrometry