France: The Largest Oyster Producer Of Europe
France is the largest shell and oyster producer in Europe (85% of the total production). The French shell production represents 153,000 tonnes and 550k€ per year. In 2009, 2,280 oyster farms employed 16,300 people. (1)
Non-detection of pathogens is responsible for up to 80% of production loss.
Since 2008, oyster farmers have had to tackle several mortality episodes in their culture resulting in up to 80% of production loss (2) . Mortality is due to infection by pathogens such as the Ostreid Herpes Virus type 1 and the bacteria Vibrio Aestuarianus.
So We Created
A quick, cheap, and field-deployable test to detect oyster pathogens in oyster farms.
Our solution at a glance
We first adapted a CRISPPR-Cas-based technique called SHERLOCK (3) to detect oyster pathogens in oyster beds in the lab. Next, we made the test deployable in the field by developing a paper-based test that is particularly easy to use by farmers.
How we did it
- We purified the Cas13a protein that, upon recognition of a specific target RNA sequence, catalyzes the degradation of large quantities of any RNA.
- We designed guide RNAs – particular sequences that assemble with Cas13a proteins – to specifically recognize cognate sequences only found in the pathogens we wanted to detect.
- We validated our strategy using scientific instruments in the lab.
- We implemented a paper-based test that uses capillarity, antibodies and gold nanoparticles to were able to read the result of the reaction with the naked eye from a drop of test solution.
We ran the SHERLOCK experiment using fluorescence output to have access to the kinetic of the reaction and we included a kinetic model in our work. Then, with information we had, we optimized the conditions for the paper-based test.
Through this process, we obtained a proof of concept.
Beyond pathogen detection, our project aims at establishing a discussion between oyster farmers and scientists, and more generally at popularizing the benefits of science.
Impact
- To better understand and meet users’ demands, we met oyster farmers, conducted a survey and participated in debates around shell farming and research.
- We discussed scientific aspects with expert researchers in the field.
- We created a booklet to spread awareness of the advantages and possibilities of early pathogen detection in situ amongst oyster farmers.
- To popularize synthetic biology we visited schools and participated in the national science fest (Fête de la Science).
- We communicated our project by participating in several student meetings and posting on social media.
Promotion Video
References
1. agreste - Françoise BEAUFILS. GRAPH’AGRI 2021 - L’agriculture, la forêt, la pêche et les industries
agroalimentaires. [Internet]. 2021. Available from:
https://agreste.agriculture.gouv.fr/agreste-web/download/publication/publie/GraFra2021Integral/GraFra2021_integral.pdf
2. Pernet F, Lagarde F. Mortalités massives de l’Huître creuse: causes et perspectives. 2011 Jul; Available from:
https://www.researchgate.net/publication/277030054_Mortalites_massives_de_l%27Huitre_creuse_causes_et_perspectives
3. J.Kellner M, Koob J, S.Gootenberg J, O.Abudayyeh O, Zhang F. SHERLOCK: Nucleic acid detection with CRISPR nucleases. 2019 Oct; Available from:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956564/