Team:British Columbia/Description
The 2019 UBC iGEM team took on a monumental challenge of global significance this year, in the addressing of a challenge that has had a particularly devastating impact on communities along the coast of British Columbia (B.C.). Shellfish are commonly consumed in B.C. due to their high protein content and natural abundance along the B.C. coastline, and represent an important segment of the local economy. Particularly within rural and indiginous communities, shellfish are a staple food with significant dietary and cultural importance(1). However, consumption of shellfish under certain environmental conditions can be fatal. Harmful algal blooms can produce potent marine biotoxins that become accumulated within the tissue of shellfish. Consumption of contaminated shellfish can lead to disastrous consequences if medical attention is not acquired immediately. As a result, self-harvesters in rural communities often refrain from eating shellfish or in cases where food is scarce, they are forced to put themselves at great risk with no medical facilities within close proximity. This risk has resulted in the deaths and severe illness of many people in B.C. and it is likely that many cases go unreported in remote communities (2). Climate change is projected to increase both the frequency and severity of harmful algal blooms which will only worsen the situation and put coastal people all around the world at a greater risk (3). As the situation worsens, the need for a solution is becoming increasingly apparent.
The UBC iGEM team has decided to focus on a specific one of these marine biotoxins that has lead to cases of death in our local community. Saxitoxin is a marine biotoxin responsible for an illness known as Paralytic Shellfish Poisoning (PSP) which paralyzes muscles and causes respiratory paralysis. It is particularly deadly as it can take effect in just 15 minutes of ingestion leaving no time to seek medical attention (4). Currently, the majority of testing for PSP toxins in B.C. is done by the CFIA in a laboratory in Vancouver using high performance liquid chromatography (HPLC) (5). They monitor PSP levels in the waters off the B.C. coast but reports are not always accurate as conditions can quickly change and frequent testing isn't always feasible. For rural communities there are on-site test kits yet they rely on expensive lab equipment, proper training and have high false postiive and negative rates. The only other option is getting their shellfish samples to the CFIA for testing but this is time consuming and expensive due to travel costs so is often disregarded. Clearly, the need for onsite testing needs to be a priority to address this issue. On-site PSP testing would allow remote communities and shellfish farmers to remove uncertainty surrounding shellfish consumption and sale. The UBC iGEM has recognized the urgency of this issue, but so has the government. Just last year, the Canadian Food Inspection Agency (CFIA) released a challenge seeking innovative devices for detecting marine biotoxins offering hundreds of thousands of dollars to the best solutions(6).
Our approach to the problem was meticulously planned out in order to provide the most effective solution possible. Our team settled on the approach of gene discovery primarily using a method known as substrate induced gene expression (SIGEX) to discover transcription factor based biosensors responsive to saxitoxin. We decided to search for a saxitoxin inducible promoter system as it could be incorporated into many systems that would allow direct on-site testing. Our team primarily looked into the use of cell-free systems to create paper test strips that could provide a simple yes or no test for the presence of saxitoxin in harmful concentrations. Cell-free systems are cheap, portable and have been tested and proven within the iGEM and scientific community on numerous occasions (7). Due to the gracious support of the Hallam lab and the University of British Columbia, our team was able to have access to cutting edge technologies such as microfluidic fluorescence cell sorters, acoustic liquid handlers and automated high-throughput screening devices that have been used before in the search for PST biosensors. Through thousands of dedicated hours in the lab, our team was able to identify potential PST inducible promoter systems that can be implemented into an onsite hardware detection system.
References
[1] Cisneros-Montemayor, A., Pauly, D., Weatherdon, L., & Ota, Y. (2016). A Global Estimate of Seafood Consumption by Coastal Indigenous Peoples. PLOS ONE, 11(12), e0166681. doi: 10.1371/journal.pone.0166681
[2] Quayle, D. (1966). Paralytic Shellfish Poisoning Safe Shellfish. Retrieved 19 October 2019, from http://www.dfo-mpo.gc.ca/Library/31230.pdf
[3] Moore, S., Trainer, V., Mantua, N., Parker, M., Laws, E., Backer, L., & Fleming, L. (2008). Impacts of climate variability and future climate change on harmful algal blooms and human health. Environmental Health, 7(Suppl 2), S4. doi: 10.1186/1476-069x-7-s2-s4
[4] NCCEH. (2013). Paralytic Shellfish Poisoning | NCCEH. Retrieved 19 October 2019, from http://www.ncceh.ca/documents/practice-scenario/paralytic-shellfish-poisoning
[5] CFIA. (2012). Retrieved 19 October 2019, from http://www.bccdc.ca/resource-gallery/Documents/Training%20and%20Events/ EH/FPS/Deirdre_MonitoringPrograms.pdf
[6] CFIA. (2018). Marine Biotoxin Detection Devices for Shellfish - Innovative Solutions Canada. Retrieved 19 October 2019, from https://www.ic.gc.ca/eic/site/101.nsf/eng/00057.html
[7] iGEM Bielefeld. (2015). Cell-Free Sticks. Retrieved 19 October 2019, from https://2015.igem.org/Team:Bielefeld-CeBiTec