UMMS Affiliation

Department of Systems Biology

Publication Date

2021-09-22

Document Type

Article

Disciplines

Environmental Microbiology and Microbial Ecology

Abstract

In spite of its relevance as a foodborne pathogen, we have limited knowledge about Listeria monocytogenes in the environment. L. monocytogenes outbreaks have been linked to fruits and vegetables; thus, a better understanding of the factors influencing its ability to colonize plants is important. We tested how environmental factors and other soil- and plant-associated bacteria influenced L. monocytogenes' ability to colonize plant roots using Arabidopsis thaliana seedlings in a hydroponic growth system. We determined that the successful root colonization of L. monocytogenes 10403S was modestly but significantly enhanced by the bacterium being pregrown at higher temperatures, and this effect was independent of the biofilm and virulence regulator PrfA. We tested 14 rhizosphere-derived bacteria for their impact on L. monocytogenes 10403S, identifying one that enhanced and 10 that inhibited the association of 10403S with plant roots. We also characterized the outcomes of these interactions under both coinoculation and invasion conditions. We characterized the physical requirements of five of these rhizobacteria to impact the association of L. monocytogenes 10403S with roots, visualizing one of these interactions by microscopy. Furthermore, we determined that two rhizobacteria (one an inhibitor, the other an enhancer of 10403S root association) were able to similarly impact 10 different L. monocytogenes strains, indicating that the effects of these rhizobacteria on L. monocytogenes are not strain specific. Taken together, our results advance our understanding of the parameters that affect L. monocytogenes plant root colonization, knowledge that may enable us to deter its association with and, thus, downstream contamination of, food crops.

IMPORTANCE Listeria monocytogenes is ubiquitous in the environment, being found in or on soil, water, plants, and wildlife. However, little is known about the requirements for L. monocytogenes' existence in these settings. Recent L. monocytogenes outbreaks have been associated with contaminated produce; thus, we used a plant colonization model to investigate factors that alter L. monocytogenes' ability to colonize plant roots. We show that L. monocytogenes colonization of roots was enhanced when grown at higher temperatures prior to inoculation but did not require a known regulator of virulence and biofilm formation. Additionally, we identified several rhizobacteria that altered the ability of 11 different strains of L. monocytogenes to colonize plant roots. Understanding the factors that impact L. monocytogenes physiology and growth will be crucial for finding mechanisms (whether chemical or microbial) that enable its removal from plant surfaces to reduce L. monocytogenes contamination of produce and eliminate foodborne illness.

Keywords

Listeria, Listeria monocytogenes, food-borne pathogens, hydroponics, plant-microbe interactions

Rights and Permissions

Copyright © 2021 Schoenborn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license.

DOI of Published Version

10.1128/AEM.01411-21

Source

Schoenborn AA, Clapper H, Eckshtain-Levi N, Shank EA. Rhizobacteria Impact Colonization of Listeria monocytogenes on Arabidopsis thaliana Roots. Appl Environ Microbiol. 2021 Nov 10;87(23):e0141121. doi: 10.1128/AEM.01411-21. Epub 2021 Sep 22. PMID: 34550783; PMCID: PMC8579980. Link to article on publisher's site

Journal/Book/Conference Title

Applied and environmental microbiology

Related Resources

Link to Article in PubMed

PubMed ID

34550783

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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