Team:Lethbridge/Applied Design

One of the numerous benefits of VINCEnT is that it has a very broad range of applications. A growing concern for Southern Alberta is the spread of the aquatic invasive species zebra and quagga mussels (Dreissena polymorpha and D. bugensis respectively). The current methods of controlling their spread are: Zequanox®, a heat killed cell lysate of Pseudomonas fluorescens; and “potash” or potassium chloride (1). Zequanox® has only been shown to be effective in very small, sectioned-off areas of water and is also a very expensive product for wide-spread use. In order for potash application to be effective, it would have to be added to concentrations just above acceptable drinking levels (2,3). Even with these constraints, because of its relatively cheap cost potash is the prefered method for zebra and quagga mussel eradication by Alberta Environment and Parks (see our Human Practices page for more details).

Method	Pros	Cons
Zequanox®	Highly specific to Dreissena spp.	Not 100% effective in eradication Not effective in large, open water bodies Expensive
Potash	Cost-effective 100% Dreissena spp. eradication efficiency	Is non-specific, being toxic to all freshwater bivalves Need large quantities to be effective Human health and threat to agriculture integrity
P22 PNC with FitD	Highly specific to Dreissena spp. Need small amounts to add to be effective Non-replicating therefore not infectious and easily controlled	More expensive and labour intensive to produce than potash

Through contacting Nicole Kimmel from Alberta Environment and Parks, Ryan Dyck from Agriculture & Agri-Food Canada, and Shannon Frank from the Oldman Watershed Council; we have found that our system may be an applicable solution to the combat the spread of zebra mussels (see our Human Practices page for more details). This has led us to design a PNC construct from the bacteriophage P22 to encapsulate the Dreissena spp. specific toxin from P. fluorescens strain CL145A, the active agent in Zequanox® (4). We have designed our PNCs to be uptaken by zebra and quagga mussels to emulate the uptake method of Zequanox® which is taken up through the mussels’ filtration system and is degraded in their digestive tracts releasing the toxin (5; see our Design page for more details).

Our system would be a safe solution to deploy into the environment because of the high specificity for zebra and quagga mussels and that our PNCs are non-replicating. FitD has been shown to be highly toxic to Dreissena spp. (5) but not the native freshwater mussel species (6). Due to the fact that PNCs only contain protein capsids, they are unable to self-replicate and must be produced in a lab environment prior to release. Our system would not be deployed into open-water bodies, but would instead be used as a preventative measure by keeping it contained to isolated regions.

References

Department of Fisheries and Oceans Canada. (2014). Lake Winnipeg Zebra Mussel treatment. DFO Canada Science Advisory Secretariat Science Response. 2014/031
Davis, E.A., Wong, W.H., & Harman, W.N. (2017). Toxicity of potassium chloride compared to sodium chloride for zebra mussel decontamination. Journal of Aquatic Animal Health. DOI: 10.1080/08997659.2017.1388866
World Health Organization. (2009). Potassium in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality. Geneva, Switzerland: WHO Press.
Boston, M. (2018). US Patent No. 0139968 A1. Washington, DC: U.S. Patent and Trademark Office.
Malloy, D.P., Mayer, D.A., Giamberini, L., & Gaylo, M.J. (2013). Mode of action of Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae). Journal of Invertebrate Pathology. 113: 115-121.
Malloy, D.P., Mayer, D.A., Gaylo, M.J., Burlakova, L.E., Karatayev, A.Y., Presti, K.T., Sawyko, P.M., & Morse, J.T. (2013). Non-target trials with Pseudomonas fluorescens strain CL145A, a lethal control agent of dreissenid mussels (Bivalvia: Dreissenidae). Management of Biological Invasions. 4(1): 71-79.