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Seed inoculation with antagonistic bacteria limits occurrence of E. coli O157:H7gfp + on baby spinach leaves

Karlsson, Maria E. ; Uhlig, Elisabeth LU ; Håkansson, Åsa LU and Alsanius, Beatrix W. (2022) In BMC Microbiology 22(1).
Abstract

Backround: During the last decades, outbreaks of foodborne illnesses have increasingly been linked to fresh and/or minimally processed fruit and vegetables. Enterohemorrhagic Escherichia coli was the causal agent for major outbreaks in Europe with leafy green vegetables and sprouts. To improve food safety, microbial antagonism has received attention during recent years and could be one of the solution to prevent contamination of food borne pathogens on fresh produce. Here we investigate the antagonistic effect of three bacterial strains (Pseudomonas orientalis, P. flavescens and Rhodococcus sp.) isolated from spinach leaves against E. coli O157:H7gfp + under laboratory and greenhouse conditions. Results: Our results shows that... (More)

Backround: During the last decades, outbreaks of foodborne illnesses have increasingly been linked to fresh and/or minimally processed fruit and vegetables. Enterohemorrhagic Escherichia coli was the causal agent for major outbreaks in Europe with leafy green vegetables and sprouts. To improve food safety, microbial antagonism has received attention during recent years and could be one of the solution to prevent contamination of food borne pathogens on fresh produce. Here we investigate the antagonistic effect of three bacterial strains (Pseudomonas orientalis, P. flavescens and Rhodococcus sp.) isolated from spinach leaves against E. coli O157:H7gfp + under laboratory and greenhouse conditions. Results: Our results shows that significantly less culturable E.coli O157:H7gfp + were retrieved from the spinach canopy subjected to antagonist seed treatment than canopy inoculation. Seeds inoculated with Rhodococcus sp. significantly reduced growth of E. coli O157:H7gfp + compared with the other antagonists. The result from the in vitro study shows a significant reduction of growth of E. coli O157:H7gfp+, but only after 44 h when E. coli O157:H7gfp + was propagated in a mixture of spent media from all three antagonists. Conclusions: The antagonistic effect on phyllospheric E.coli O157:H7gfp + observed after seed inoculation with Rhodococcus sp. might be an indication of induced resistance mechanism in the crop. In addition, there was a small reduction of culturable E.coli O157:H7gfp + when propagated in spent media from all three antagonists. Nutritional conditions rather than metabolites formed by the three chosen organisms appear to be critical for controlling E. coli O157:H7gfp+.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Bacterial antagonist, E. coli O157:H7, Pseudomonas flavescens, Pseudomonas orientalis, Rhodococcus sp, Spinach
in
BMC Microbiology
volume
22
issue
1
article number
131
publisher
BioMed Central (BMC)
external identifiers
  • pmid:35568814
  • scopus:85130044945
ISSN
1471-2180
DOI
10.1186/s12866-022-02550-w
language
English
LU publication?
yes
id
c463a713-37ce-4a6e-8000-a839e1d13855
date added to LUP
2022-12-29 11:45:31
date last changed
2024-04-18 17:24:07
@article{c463a713-37ce-4a6e-8000-a839e1d13855,
  abstract     = {{<p>Backround: During the last decades, outbreaks of foodborne illnesses have increasingly been linked to fresh and/or minimally processed fruit and vegetables. Enterohemorrhagic Escherichia coli was the causal agent for major outbreaks in Europe with leafy green vegetables and sprouts. To improve food safety, microbial antagonism has received attention during recent years and could be one of the solution to prevent contamination of food borne pathogens on fresh produce. Here we investigate the antagonistic effect of three bacterial strains (Pseudomonas orientalis, P. flavescens and Rhodococcus sp.) isolated from spinach leaves against E. coli O157:H7gfp + under laboratory and greenhouse conditions. Results: Our results shows that significantly less culturable E.coli O157:H7gfp + were retrieved from the spinach canopy subjected to antagonist seed treatment than canopy inoculation. Seeds inoculated with Rhodococcus sp. significantly reduced growth of E. coli O157:H7gfp + compared with the other antagonists. The result from the in vitro study shows a significant reduction of growth of E. coli O157:H7gfp+, but only after 44 h when E. coli O157:H7gfp + was propagated in a mixture of spent media from all three antagonists. Conclusions: The antagonistic effect on phyllospheric E.coli O157:H7gfp + observed after seed inoculation with Rhodococcus sp. might be an indication of induced resistance mechanism in the crop. In addition, there was a small reduction of culturable E.coli O157:H7gfp + when propagated in spent media from all three antagonists. Nutritional conditions rather than metabolites formed by the three chosen organisms appear to be critical for controlling E. coli O157:H7gfp+.</p>}},
  author       = {{Karlsson, Maria E. and Uhlig, Elisabeth and Håkansson, Åsa and Alsanius, Beatrix W.}},
  issn         = {{1471-2180}},
  keywords     = {{Bacterial antagonist; E. coli O157:H7; Pseudomonas flavescens; Pseudomonas orientalis; Rhodococcus sp; Spinach}},
  language     = {{eng}},
  number       = {{1}},
  publisher    = {{BioMed Central (BMC)}},
  series       = {{BMC Microbiology}},
  title        = {{Seed inoculation with antagonistic bacteria limits occurrence of E. coli O157:H7gfp + on baby spinach leaves}},
  url          = {{http://dx.doi.org/10.1186/s12866-022-02550-w}},
  doi          = {{10.1186/s12866-022-02550-w}},
  volume       = {{22}},
  year         = {{2022}},
}