Patent Filed for Novel Method to Detect Toxin in Fresh Water
Test kits now available to identify lethal neurotoxin-producing cyanobacteria
Bakir Al-Sinawi, who helped develop guanitoxin testing kit. Photo: Diagnostic Technology
A new freshwater monitoring tool, which can detect a lethal toxin called guanitoxin in freshwater sources, is now available to public health officials thanks to technology developed at Scripps Institution of Oceanography at UC San Diego and the University of São Paulo.
This novel technology has been licensed to the Australian company Diagnostic Technology, which is now offering guanitoxin monitoring kits under the brand Phytoxigene.
“It was really gratifying to be able to unlock how nature has solved this ability to make this toxin,” Scripps Oceanography marine chemical biologist Bradley Moore said about the research that led to the kits.
Guanitoxin is one of several neurotoxins produced by cyanobacteria, which proliferate to form harmful cyanobacterial blooms (cyanoHABs) in lakes and ponds.
Harmful algal blooms (HABs) and cyanoHABs can contaminate tap water reservoirs and have caused significant public health emergencies. In 2014, Toledo, Ohio issued a “do not drink” advisory after a HAB outbreak led to toxins other than guanitoxin entering the city’s tap water supply. Essential healthcare treatments such as dialysis and surgery had to be halted. Additionally, people who swim in waters with HABs have suffered adverse health effects, ranging from vomiting to neurological impairment. These toxins have also been responsible for a number of dog deaths.
Guanitoxin is a highly toxic neurotoxin formed by cyanobacteria, but until recently, the genes responsible for its biosynthesis were unknown. Detection of guanitoxin has lagged behind detection of other neurotoxins due to its incompatibility with many traditional analytical methods and lower stability in the environment. In May 2022, Stella Lima, a former visiting scholar at Scripps Oceanography, along with colleagues in the lab of Moore and collaborators from UC Santa Cruz and University of São Paolo, published a paper establishing the precise functions of all nine enzymes responsible for guanitoxin biosynthesis.
“We realized that there was one gene in particular that coded an enzyme that was much more unusual than others, and it was pretty rare,” Moore said.
Armed with this discovery, the team developed a method to probe environmental samples specifically for that gene, which would indicate the presence of guanitoxin. The researchers filed the patent for this technology in February 2022, and it is currently under review.
Mark van Asten, chief executive officer of Phytoxigene, described the company’s kit as “able to take this fascinating research and offer a way for people to identify this previously difficult to identify toxin producer in a more rapid and standardized way.”
In October 2021, Scripps Oceanography, and University of São Paolo researchers licensed their technology for guanitoxin detection to Phytoxigene, Inc, which incorporated it into an existing assay for the detection of another HAB toxin called anatoxin. The commercialization of this new detection method means that guanitoxin could one day become part of standard toxin monitoring in freshwater environments.
The collaborators emphasized the importance of partnership and real-world applications of research in describing the breakthrough. Moore said that the project has been particularly meaningful because it unveiled fascinating basic science, which can then be used to inform applied and environmental sciences. Phytoxigene Director of Business Development for North America Greg Ford said the “partnership between academia and industry is paramount in sciences. The industry does not exist without the partnerships.”
“And equally, these relationships allow for better research and better outcomes, which are essential,” van Asten added.
Besides Moore, patent co-inventors are Timothy Fallon and Jonathan Chekan of Scripps Institution of Oceanography, Shaun McKinnie of University of California Santa Cruz, Stella Lima and Marli Fiore of the University of São Paolo.
Theodora Mautz is a first-year PhD student in marine biology and works in the Semmens Lab at Scripps Institution of Oceanography at UC San Diego.
About Scripps Oceanography
Scripps Institution of Oceanography at the University of California San Diego is one of the world’s most important centers for global earth science research and education. In its second century of discovery, Scripps scientists work to understand and protect the planet, and investigate our oceans, Earth, and atmosphere to find solutions to our greatest environmental challenges. Scripps offers unparalleled education and training for the next generation of scientific and environmental leaders through its undergraduate, master’s and doctoral programs. The institution also operates a fleet of four oceanographic research vessels, and is home to Birch Aquarium at Scripps, the public exploration center that welcomes 500,000 visitors each year.
About UC San Diego
At the University of California San Diego, we embrace a culture of exploration and experimentation. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren’t afraid to look deeper, challenge expectations and redefine conventional wisdom. As one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth and make our world a better place. Learn more at ucsd.edu.