SANTA CRUZ – UC Santa Cruz students delivered the university its second straight gold medal from the International Genetically Engineered Machine competition.
The iGEM foundation recognized the students for their research into a sequence specific gene elimination mechanism. It works by eliminating a specific gene of any organism without killing the cell or harming any other cells or genes in the organism, according to Torrey Brownell, a senior at UCSC.
The team’s research focused on eliminating the gene that produces the shiga toxin responsible for E. coli infections.
“This is a fairly local problem where we have farmers and packagers and distributers around Santa Cruz who have had these outbreaks, which means they’ve had to do recalls, had to throw away all the food. That’s a lot of waste and burden on those around us,” said Stephen Hwang, a fourth-year grad student at UCSC. “So, we have the element of generalizability but also a focus on a local issue that we’ve seen be a problem.”
While their research has not gone into practice yet, Brownell noted it could have two practical applications to stop E. coli and prevent recalls on afflicted foods.
First, the team could develop a suppository pill for cattle farmers to use on their livestock and stop the disease at its source in the bovine’s bowels. Since the mechanism is designed to target only the gene in the bacteria responsible for E. coli production, it should be of no harm to the animal.
Alternatively, the students also determined they could cut out the disease at the food production stage. Theoretically the mechanism could instead be added to water and purify crops of the bacteria when the vegetables are washed.
The team has not conducted live model testing yet. However, theoretically either method would be safe for human consumption of treated foods since the mechanism only targets specific genetics within the bacteria, Brownell noted.
“The idea is if this is used, this could be a good alternative to different really harmful chemicals that are used already or different antibodies that are being used, as well,” Hwang said. “This doesn’t indiscriminately kill all bacteria.”
To understand the issue more accurately, the team also reached out to local farmers and gauged interest in the technology it was researching. They found the parties that were affected by E. coli outbreaks interested in the research.
Cattle farmers saw very few drawbacks from an E. coli outbreak, and thus were less financially motivated to invest in technology such as this, Brownell noted. However, vegetable farmers were more driven to find solutions to an issue they had little control over.
That discovery could sway the practical application of the research, but the team is still looking into ways to make both avenues successful such as government regulation on livestock before deciding a route to take.
“It was very interesting to talk to all the different players of this one aspect,” Brownell said. “The people who are being hurt wanted things to be done, but didn’t necessarily have the power to control anything. We wanted to provide a method that would be able to support them.”
Further research on how to apply the mechanism is likely to happen during the next two quarters at UCSC, Brownell said. The group is expected to dwindle from 18 to about six students for practical research.
The team’s gold medal is the result of nearly 15 months of preparation. Brownell and Hwang assembled the research team in August 2020. During the school year, the team managed to set aside much of its research time during class, which dedicated about six hours a day to the team.
During the summer, research became a fulltime job. The crew of student researchers were expected to be in the lab all day as if it were a 9-5 job, and as the competition approached, 5 p.m. began to stretch later.
“Our team really stepped up on that. I never felt like we didn’t have enough manpower, or we were fighting to get everybody to come in,” Brownell said. “Everybody was still excited and motivated to be here.”
All that work resulted in the team following in the footsteps of the university’s previous team, Koma Plastics, which won a gold medal at iGEM in 2020 for developing a biodegradable agricultural plastic out of cellulose. In turn, the 2021 iGEM continued to represent the university as renowned research institution on the global scale.
“(It was) pretty monumentous. It was a year’s work leading up to that one gold medal. Through that time, I think everyone on the team has grown so much.”
Not only did the team represent the university, but it also expressed the good that can come from bioengineering. Hwang and Brownell discerned their team’s research could be modified to target more than just that specific strain of E. coli.
In order to target other diseases, such as antibiotic resistant MRSA, the team would need to change the type of bacteriophage it uses, the target spacers and likely an additional conjugation method gene. Those are the three modifiable aspects that allow its research to be applied to diseases across the spectrum.
Brownell noted the team’s work was important for the public perception of bioengineering, especially in a world where people can be weary from misunderstandings of genetically modified organisms.
“This is a good example of how bioengineering can be a really positive social good,” Brownell said. “Our team and many others in the iGEM competition are showing that this realm of biology is going to be and is continuing to be a useful way of treating human diseases and progressing society.”