Virulence test using nematodes to prescreen Nocardia species capable of inducing neurodegeneration and behavioral disorders
- Published
- Accepted
- Subject Areas
- Microbiology, Neuroscience, Infectious Diseases
- Keywords
- Nocardia, C. elegans, Parkinson's symptoms, neuronal apoptosis, rapid virulence test
- Copyright
- © 2017 Claire et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Virulence test using nematodes to prescreen Nocardia species capable of inducing neurodegeneration and behavioral disorders. PeerJ Preprints 5:e3152v1 https://doi.org/10.7287/peerj.preprints.3152v1
Abstract
Background. Parkinson’s disease (PD) is a disorder characterized by dopaminergic neuron programmed cell death. The etiology of PD remains uncertain—some cases are due to selected genes associated with familial heredity, others are due to environmental exposure to toxic components, but over 90% of cases have a sporadic origin. Nocardia are Actinobacteria that can cause human diseases like nocardiosis. This illness can lead to lung infection or central nervous system (CNS) invasion in both immunocompromised and immunocompetent individuals. The main species involved in CNS are N. farcinica, N. nova, N. brasiliensis and N. cyriacigeorgica. Some studies have highlighted the ability of N. cyriacigeorgica to induce Parkinson’s disease-like symptoms in animals. Actinobacteria are known to produce a large variety of secondary metabolites, some of which can be neurotoxic. We hypothesized that neurotoxic secondary metabolite production and the onset of PD-like symptoms in animals could be linked. Methods. Here we used a method to screen bacteria that could induce dopaminergic neurodegeneration before performing mouse experiments. Results.The nematode Caenorhabditis elegans allowed us to demonstrate that Nocardia strains belonging to N. cyriacigeorgica and N. farcinica species can induce dopaminergic neurodegeneration. Strains of interest involved with the nematodes in neurodegenerative disorders were then injected in mice. Infected mice had behavioral disorders that may be related to neuronal damage, thus confirming the ability of Nocardia strains to induce neurodegeneration. These behavioral disorders were induced by N. cyriacigeorgica species (N. cyriacigeorgica GUH-2 and N. cyriacigeorgica 44484) and N. farcinica 10152. Discussion.We conclude that C. elegans is a good model for detecting Nocardia strains involved in neurodegeneration. This model allowed us to detect bacteria with high neurodegenerative effects and which should be studied in mice to characterize the induced behavioral disorders and bacterial dissemination.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Mice infected by N. cyriacigeorgica GUH-2 presenting motor symptoms
Behavioral disorders in two mice. One with the rhythmic and vertical movements of the head (mouse up) and the other with hemiparesis (mouse down)
Number of nematodes affected in their movement using the touch response test
Wild type response to the touch response test is characterised by backward movements of the nematode and then a leak forward. We compared this reaction on N2 and BY250 nematodes lineages that were not in contact with supernatant (control). Nematode affected had the same reactions following the touching but with slow reactions or only backwards. We observed also forwards / backwards movements or motionless nematodes with only a movement of the nose. These kinds of phenotypes were observed on nematodes that were in contact with bacterial supernatant (N.farcinica 10152 or N.cyriacigeorgica GUH-2).