Skip to Main content Skip to Navigation
Journal articles

Entomopathogenic nematode-associated microbiota: from monoxenic paradigm to pathobiome

Abstract : BACKGROUND: The holistic view of bacterial symbiosis, incorporating both host and microbial environment, constitutes a major conceptual shift in studies deciphering host-microbe interactions. Interactions between Steinernema entomopathogenic nematodes and their bacterial symbionts, Xenorhabdus, have long been considered monoxenic two partner associations responsible for the killing of the insects and therefore widely used in insect pest biocontrol. We investigated this "monoxenic paradigm" by profiling the microbiota of infective juveniles (IJs), the soil-dwelling form responsible for transmitting Steinernema-Xenorhabdus between insect hosts in the parasitic lifecycle. RESULTS: Multigenic metabarcoding (16S and rpoB markers) showed that the bacterial community associated with laboratory-reared IJs from Steinernema carpocapsae, S. feltiae, S. glaseri and S. weiseri species consisted of several Proteobacteria. The association with Xenorhabdus was never monoxenic. We showed that the laboratory-reared IJs of S. carpocapsae bore a bacterial community composed of the core symbiont (Xenorhabdus nematophila) together with a frequently associated microbiota (FAM) consisting of about a dozen of Proteobacteria (Pseudomonas, Stenotrophomonas, Alcaligenes, Achromobacter, Pseudochrobactrum, Ochrobactrum, Brevundimonas, Deftia, etc.). We validated this set of bacteria by metabarcoding analysis on freshly sampled IJs from natural conditions. We isolated diverse bacterial taxa, validating the profile of the Steinernema FAM. We explored the functions of the FAM members potentially involved in the parasitic lifecycle of Steinernema. Two species, Pseudomonas protegens and P. chlororaphis, displayed entomopathogenic properties suggestive of a role in Steinernema virulence and membership of the Steinernema pathobiome. CONCLUSIONS: Our study validates a shift from monoxenic paradigm to pathobiome view in the case of the Steinernema ecology. The microbial communities of low complexity associated with EPNs will permit future microbiota manipulation experiments to decipher overall microbiota functioning in the infectious process triggered by EPN in insects and, more generally, in EPN ecology.
Document type :
Journal articles
Complete list of metadata

Cited literature [95 references]  Display  Hide  Download
Contributor : Archive Ouverte Prodinra <>
Submitted on : Monday, March 9, 2020 - 8:11:20 PM
Last modification on : Thursday, June 17, 2021 - 2:54:02 PM
Long-term archiving on: : Wednesday, June 10, 2020 - 5:20:04 PM


Ogier 2020 Microbiome.pdf
Explicit agreement for this submission


Distributed under a Creative Commons Attribution 4.0 International License



Jean-Claude Ogier, Sylvie Pages, Marie Frayssinet, Sophie Gaudriault. Entomopathogenic nematode-associated microbiota: from monoxenic paradigm to pathobiome. Microbiome, BioMed Central, 2020, 8 (1), pp.1-17. ⟨10.1186/s40168-020-00800-5⟩. ⟨hal-02503304⟩



Record views


Files downloads