Keeping the Food We Eat Safer
Suri Iyer, an assistant professor of chemistry in the McMicken College of Arts and Sciences received a grant from the National Science Foundation (NSF) for his research, Tailored Glycoconjugates for the Precise Detection of Toxins and Pathogens. The grant, an NSF CAREER award of $575,000, will allow Iyer to do fundamental research toward developing molecules that can function as biosensors to identify food-borne toxins released from Escherichia coli.
The long-term goal is to develop these molecular biosensors so they can serve as a tool for rapid detection of such food-borne toxins. Toxins produced by bacteria and other bugs are released by cells at the molecular level. Iyers group creates a type of carbohydrate called a glycoconjugate that they hope will eventually be used as a means of detecting the presence of the toxin. The carbohydrates recognize the toxins on a surface, react and cause something to change like the color of a solution, which could be read by a measuring device, for example. In this way, the carbohydrates are called a recognition molecule.
Researchers working in Iyers lab make the molecules and then go to the lab of Alison Weiss, a professor of molecular genetics in UCs College of Medicine, to test them. (Weiss is the principal investigator on a grant of her own to create the actual devices.)
One example of a toxin that the carbohydrates could recognize are the shiga toxins, such as E. coli. When ingested through improper food handling, the toxins released often cause severe gastric distress leading to kidney damage and even death.
Children, elderly people and those who are immuno-compromised are often prescribed antibiotics to kill the bacteria, says Iyer. But this can cause a problem because the bacteria basically say, OK, if Im going to die, then Im going to take everyone with me, and they release more toxin. The Centers for Disease Control and Prevention actually recommends not giving antibiotics in shiga outbreaks, because once complications begin occurring its too late. The sensors that we are working to develop would detect the toxins.
Iyer hopes to apply this knowledge to many pathogens and pathways. For example, he and his team are working with a company in Dayton, UES, Inc., to develop a device that would be right on a package of meat to tell the consumer that it is safe to buy.
Some of the toxins that are dangerous to humans dont affect animals at all, so Iyer and Weiss see applications all along the process.
Im involved in the biology at the packing plant testing the cattle as they go in before theyre slaughtered, says Weiss, For example, a recent outbreak involving spinach and lettuce was carried by cattle. The bacteria were in the streams, which feral pigs had drunk from and then trooped across fields, as feral pigs do, leaving deposits. Because of mechanized farming, the little piggy gifts get scooped up right along with everything else.
It makes sense to test as close to the source as possible, Weiss continues. It is highly unlikely that it will become contaminated downstream.
While Iyer is sole investigator on the NSF grant, he is the co-investigator on Weisss National Institutes of Health grant. Weiss points out that when Iyer was being considered for the position at UC, he made contact with her to discuss her research. She says that their cross-college interdisciplinary research is really very powerful.
People tend to get immersed in their only own discipline, she says. But Suri is actually a better biologist than I am a chemist! Its a very productive collaboration.
Alison has been very instrumental in guiding me and my students in our research and has served as a mentor to me, Iyer says. I owe her a great deal of gratitude.
Im very proud of him, says Weiss.
Iyer pays that mentorship forward by turning around and mentoring others. A secondary component to the NSF award is education. A small portion of the grant funds bring local high school students to Iyers lab to work in partnership with a UC undergraduate and graduate student. One of Iyers graduate students, Dan Lewallen, recently garnered some national attention by being chosen to attend the
of Nobel recipients for his work.
Ive really enjoyed working in Dr. Iyers lab, says Lewallen. He allows us to grow professionally but not just on a scientific basis. He encourages us to experiment, to try out what we want to pursue. Hes the perfect PhD advisor, because as a doctoral student, I have to develop my own ideas.
Through this NSF CAREER award, we will bring under-represented and economically disadvantaged high-school students to a real science lab, says Iyer. I get them out of the fast food restaurant jobs to show them what real scientists do what is possible for them to become. Its not just about the money.
Iyer tries to stay in contact with all the young students after they leave his lab.
They are either still in high school or have gone on to some of the top colleges, such as UC, Princeton, San Diego/Scripps and Urbana-Champaign, says Iyer. This is a good thing helping a lot of people and creating impact.
"I would recommend Suri as one of the best mentors in the department, adds Lewallen.
Besides continuing a tradition of mentorship, Iyer also continues another long-held tradition in the Department of Chemistry in McMicken College.
, says Iyer. Im happy to continue that tradition.
Chemistry student Dan Lewallen attends the 59th Meeting of Nobel Laureates in Lindau, Germany, June 28 July 3. Whats even more timely is Lewallens research.
Suri Iyers research is funded through National Science Foundation CAREER Award #0845005. This award was funded under the American Recovery and Reinvestment Act (ARRA) of 2009.