Effects of different media on the enrichment of low numbers of Shiga toxin-producing Escherichia coli in mung bean sprouts and on the development of the sprout microbiome

H. Margot, T. Tasara, M.H. Zwietering, H.M.L.J. Joosten, R. Stephan

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)

Abstract

Sprouted seeds have been implicated in a number of serious outbreaks caused by Salmonella and Shiga toxinproducing Escherichia coli. Sprouts pose a very complex challenge to bacterial pathogen enrichment and detection since they naturally contain high levels of background microflora including members of the
Enterobacteriaceae. As such, the currently used method cannot ensure reliable detection of STEC in sprouts. In this study, we compared different media for the enrichment of Enterobacteriaceae in their ability to promote the growth of stressed STEC at 37 °C and 42 °C. Mung bean sprouts were spiked with low levels of STEC and their growth was recorded over time. In addition, the microbiome of mung bean sprouts was analysed before and after enrichment. Our results indicate that the growth of dry-stressed STEC is comparable in all of the tested
enrichment media except for mTSB + Novobiocin and not influenced by the incubation temperature. Low levels of STEC spiked into the sprouts resuspended in media only grew to levels of around 4 log cfu/ml during enrichment,
which could reduce the probability of detection. Proteobacteria was the dominant phylum detected within the microbiome of non-enriched mung bean sprouts. During enrichment in EE-broth, Proteobacteria remained the most abundant phylum. In contrast, during enrichment in BPW the relative abundance of Proteobacteria decreased whereas Firmicutes increased when compared to the non-enriched mung bean sprout microbiome. The microbiome composition was not significantly influenced by the incubation temperature during enrichment
in both BPW and EE-broth. This is the first study to examine the microbiome on sprouted mung bean seeds during BPW and EE enrichment and relates the bacterial community composition changes to the enrichment of pathogens.
LanguageEnglish
Pages26-34
JournalInternational Journal of Food Microbiology
Volume232
DOIs
Publication statusPublished - 2016

Fingerprint

bean sprouts
Shiga-Toxigenic Escherichia coli
sprouts (food)
Shiga toxin-producing Escherichia coli
Microbiota
mung beans
Proteobacteria
Growth
Novobiocin
novobiocin
Temperature
Firmicutes
pathogens
Enterobacteriaceae
seeds
Seedlings
bacterial communities
Salmonella
Disease Outbreaks
Seeds

Cite this

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title = "Effects of different media on the enrichment of low numbers of Shiga toxin-producing Escherichia coli in mung bean sprouts and on the development of the sprout microbiome",
abstract = "Sprouted seeds have been implicated in a number of serious outbreaks caused by Salmonella and Shiga toxinproducing Escherichia coli. Sprouts pose a very complex challenge to bacterial pathogen enrichment and detection since they naturally contain high levels of background microflora including members of theEnterobacteriaceae. As such, the currently used method cannot ensure reliable detection of STEC in sprouts. In this study, we compared different media for the enrichment of Enterobacteriaceae in their ability to promote the growth of stressed STEC at 37 °C and 42 °C. Mung bean sprouts were spiked with low levels of STEC and their growth was recorded over time. In addition, the microbiome of mung bean sprouts was analysed before and after enrichment. Our results indicate that the growth of dry-stressed STEC is comparable in all of the testedenrichment media except for mTSB + Novobiocin and not influenced by the incubation temperature. Low levels of STEC spiked into the sprouts resuspended in media only grew to levels of around 4 log cfu/ml during enrichment,which could reduce the probability of detection. Proteobacteria was the dominant phylum detected within the microbiome of non-enriched mung bean sprouts. During enrichment in EE-broth, Proteobacteria remained the most abundant phylum. In contrast, during enrichment in BPW the relative abundance of Proteobacteria decreased whereas Firmicutes increased when compared to the non-enriched mung bean sprout microbiome. The microbiome composition was not significantly influenced by the incubation temperature during enrichmentin both BPW and EE-broth. This is the first study to examine the microbiome on sprouted mung bean seeds during BPW and EE enrichment and relates the bacterial community composition changes to the enrichment of pathogens.",
author = "H. Margot and T. Tasara and M.H. Zwietering and H.M.L.J. Joosten and R. Stephan",
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Effects of different media on the enrichment of low numbers of Shiga toxin-producing Escherichia coli in mung bean sprouts and on the development of the sprout microbiome. / Margot, H.; Tasara, T.; Zwietering, M.H.; Joosten, H.M.L.J.; Stephan, R.

In: International Journal of Food Microbiology, Vol. 232, 2016, p. 26-34.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Effects of different media on the enrichment of low numbers of Shiga toxin-producing Escherichia coli in mung bean sprouts and on the development of the sprout microbiome

AU - Margot, H.

AU - Tasara, T.

AU - Zwietering, M.H.

AU - Joosten, H.M.L.J.

AU - Stephan, R.

PY - 2016

Y1 - 2016

N2 - Sprouted seeds have been implicated in a number of serious outbreaks caused by Salmonella and Shiga toxinproducing Escherichia coli. Sprouts pose a very complex challenge to bacterial pathogen enrichment and detection since they naturally contain high levels of background microflora including members of theEnterobacteriaceae. As such, the currently used method cannot ensure reliable detection of STEC in sprouts. In this study, we compared different media for the enrichment of Enterobacteriaceae in their ability to promote the growth of stressed STEC at 37 °C and 42 °C. Mung bean sprouts were spiked with low levels of STEC and their growth was recorded over time. In addition, the microbiome of mung bean sprouts was analysed before and after enrichment. Our results indicate that the growth of dry-stressed STEC is comparable in all of the testedenrichment media except for mTSB + Novobiocin and not influenced by the incubation temperature. Low levels of STEC spiked into the sprouts resuspended in media only grew to levels of around 4 log cfu/ml during enrichment,which could reduce the probability of detection. Proteobacteria was the dominant phylum detected within the microbiome of non-enriched mung bean sprouts. During enrichment in EE-broth, Proteobacteria remained the most abundant phylum. In contrast, during enrichment in BPW the relative abundance of Proteobacteria decreased whereas Firmicutes increased when compared to the non-enriched mung bean sprout microbiome. The microbiome composition was not significantly influenced by the incubation temperature during enrichmentin both BPW and EE-broth. This is the first study to examine the microbiome on sprouted mung bean seeds during BPW and EE enrichment and relates the bacterial community composition changes to the enrichment of pathogens.

AB - Sprouted seeds have been implicated in a number of serious outbreaks caused by Salmonella and Shiga toxinproducing Escherichia coli. Sprouts pose a very complex challenge to bacterial pathogen enrichment and detection since they naturally contain high levels of background microflora including members of theEnterobacteriaceae. As such, the currently used method cannot ensure reliable detection of STEC in sprouts. In this study, we compared different media for the enrichment of Enterobacteriaceae in their ability to promote the growth of stressed STEC at 37 °C and 42 °C. Mung bean sprouts were spiked with low levels of STEC and their growth was recorded over time. In addition, the microbiome of mung bean sprouts was analysed before and after enrichment. Our results indicate that the growth of dry-stressed STEC is comparable in all of the testedenrichment media except for mTSB + Novobiocin and not influenced by the incubation temperature. Low levels of STEC spiked into the sprouts resuspended in media only grew to levels of around 4 log cfu/ml during enrichment,which could reduce the probability of detection. Proteobacteria was the dominant phylum detected within the microbiome of non-enriched mung bean sprouts. During enrichment in EE-broth, Proteobacteria remained the most abundant phylum. In contrast, during enrichment in BPW the relative abundance of Proteobacteria decreased whereas Firmicutes increased when compared to the non-enriched mung bean sprout microbiome. The microbiome composition was not significantly influenced by the incubation temperature during enrichmentin both BPW and EE-broth. This is the first study to examine the microbiome on sprouted mung bean seeds during BPW and EE enrichment and relates the bacterial community composition changes to the enrichment of pathogens.

U2 - 10.1016/j.ijfoodmicro.2016.05.005

DO - 10.1016/j.ijfoodmicro.2016.05.005

M3 - Article

VL - 232

SP - 26

EP - 34

JO - International Journal of Food Microbiology

T2 - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

ER -