Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.

Shiga toxin-producing Escherichia coli (STEC) is causing outbreaks worldwide and a rapid detection method is urgently needed. Loop-mediated isothermal amplification (LAMP) has attracted attention in the development of pathogen detection methods; however, current methods for the detection of LAMP amp...

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Main Authors: Alaa H Sewid, Joseph H Ramos, Haley C Dylewski, Gillian I Castro, Doris H D'Souza, Shigetoshi Eda
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0320393
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author Alaa H Sewid
Joseph H Ramos
Haley C Dylewski
Gillian I Castro
Doris H D'Souza
Shigetoshi Eda
author_facet Alaa H Sewid
Joseph H Ramos
Haley C Dylewski
Gillian I Castro
Doris H D'Souza
Shigetoshi Eda
author_sort Alaa H Sewid
collection DOAJ
description Shiga toxin-producing Escherichia coli (STEC) is causing outbreaks worldwide and a rapid detection method is urgently needed. Loop-mediated isothermal amplification (LAMP) has attracted attention in the development of pathogen detection methods; however, current methods for the detection of LAMP amplicon suffer some drawbacks. In this study, we designed a new LAMP method by incorporating peroxidase-mimicking G-quadruplex DNAzyme for a simple colorimetric detection of the LAMP amplicon. As the new method produces LAMP amplicon containing two DNAzyme molecules per amplification unit, the method was termed colorimetric Dual DNAzyme LAMP (cDDLAMP). cDDLAMP was developed targeting 3 common STEC's virulence genes (stx1, stx2, and eae) that are associated with serious human illnesses such hemorrhagic colitis and hemolytic-uremic syndrome. Immunomagnetic enrichment was used for specific, ultrasensitive, and fast detection of STEC in food samples (leafy vegetables and milk). The sensitivity of cDDLAMP ranged from 1-100 CFU/mL in pure culture to 100-103 CFU/mL in spiked milk, and 104-109 CFU/25g of lettuce. No cross-reaction with other generic E. coli strains and non-E. coli bacteria was observed. The color signal could be observed by the naked eye or analyzed by either UV-Vis spectra or smartphone platforms. Therefore, the cDDLAMP assay is a cost-effective method for detecting STEC strains without expensive machines or extraction methods.
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spelling doaj-art-ad7355e2ac1b4f058183ee40a0932a022025-08-20T03:14:08ZengPublic Library of Science (PLoS)PLoS ONE1932-62032025-01-01204e032039310.1371/journal.pone.0320393Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.Alaa H SewidJoseph H RamosHaley C DylewskiGillian I CastroDoris H D'SouzaShigetoshi EdaShiga toxin-producing Escherichia coli (STEC) is causing outbreaks worldwide and a rapid detection method is urgently needed. Loop-mediated isothermal amplification (LAMP) has attracted attention in the development of pathogen detection methods; however, current methods for the detection of LAMP amplicon suffer some drawbacks. In this study, we designed a new LAMP method by incorporating peroxidase-mimicking G-quadruplex DNAzyme for a simple colorimetric detection of the LAMP amplicon. As the new method produces LAMP amplicon containing two DNAzyme molecules per amplification unit, the method was termed colorimetric Dual DNAzyme LAMP (cDDLAMP). cDDLAMP was developed targeting 3 common STEC's virulence genes (stx1, stx2, and eae) that are associated with serious human illnesses such hemorrhagic colitis and hemolytic-uremic syndrome. Immunomagnetic enrichment was used for specific, ultrasensitive, and fast detection of STEC in food samples (leafy vegetables and milk). The sensitivity of cDDLAMP ranged from 1-100 CFU/mL in pure culture to 100-103 CFU/mL in spiked milk, and 104-109 CFU/25g of lettuce. No cross-reaction with other generic E. coli strains and non-E. coli bacteria was observed. The color signal could be observed by the naked eye or analyzed by either UV-Vis spectra or smartphone platforms. Therefore, the cDDLAMP assay is a cost-effective method for detecting STEC strains without expensive machines or extraction methods.https://doi.org/10.1371/journal.pone.0320393
spellingShingle Alaa H Sewid
Joseph H Ramos
Haley C Dylewski
Gillian I Castro
Doris H D'Souza
Shigetoshi Eda
Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
PLoS ONE
title Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
title_full Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
title_fullStr Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
title_full_unstemmed Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
title_short Colorimetric dual DNAzyme reaction triggered by loop-mediated isothermal amplification for the visual detection of Shiga toxin-producing Escherichia coli in food matrices.
title_sort colorimetric dual dnazyme reaction triggered by loop mediated isothermal amplification for the visual detection of shiga toxin producing escherichia coli in food matrices
url https://doi.org/10.1371/journal.pone.0320393
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