CSI for our food supply

Dr. Patricia Hatch & Shawnta Lloyd

Mention the words “forensic science” and most people immediately think of crime scene investigation. But extending the science beyond fingerprints and DNA, teacher-student research team, Dr. Patricia Hatch and Shawnta Lloyd recently spent their summer vacations at the Johns Hopkins University Applied Physics Laboratory (APL) to determine what role forensic chemistry plays in protecting our nation's food supply.

As participants in the U.S. Department of Homeland Security’s (DHS) Summer Research Team Program for Minority Serving Institutions, which is administered by the Oak Ridge Institute for Science and Education, Hatch and Lloyd focused their research on ricin, a natural toxin that the Centers for Disease Control and Prevention has designated as a possible agent of biological warfare.

As a highly toxic substance, it takes only a small amount of ricin to cause death in an exposed individual, but unlike other toxic substances, ricin is not hard to obtain.

“Ricin is a natural poison created as a byproduct when castor beans are processed into castor oil, a product that the U.S. Department of Agriculture reports as having a worldwide market of more than $400 million each year,” Hatch said. “This demand produces large amounts of ricin, making it easily accessible and potentially catastrophic if used in a bioterrorism incident.”

In fact, because ricin is easily accessible, opportunities to create havoc and hysteria are plentiful. And with no antidote for infection, ricin contamination of our water and food supply offers the perfect method for bioterrorism.

At the APL facility, Hatch and Lloyd studied a variety of lectins, or sugar-binding proteins, and characterized them based on a set of distinct features. The protein showing the greatest similarity in structure and function to ricin will be used as a surrogate in future studies.

“As a highly toxic substance, it is not safe to work with large amounts of ricin when trying to study its behavior,” said Lloyd. “A non-toxic surrogate could be used in large-scale simulations to predict the behavior of ricin in different foods, beverages and other methods of exposure.”

Symptoms of ricin poisoning can vary depending on the method of exposure, but accidental exposure is unlikely except for with the ingestion of castor beans. In addition to ingestion, ricin can also be inhaled or injected. Either way, the body’s reaction can be quite severe, eventually causing death by getting inside the body’s cells and preventing them from making the proteins they need.

As an assistant professor of chemistry and a forensic chemistry coordinator at Hampton (Va.) University, Hatch said she is looking forward to using this experience and applying it within her classroom. Lloyd, who is one of Hatch’s undergraduate students, feels she has gained a leg-up on her classmates.

“I think that this experience has made me more confident in my career goals. For example, I realize I want to pursue a higher degree than I did before,” said Lloyd. “I think I've also learned lab and research skills that I can incorporate into my classes when I return to school.”

The team’s mentor, Dr. Charles Young, is a senior staff scientist for APL and serves as a research investigator for the National Center for Food Protection and Defense (NCFPD). He notes that as a DHS Center of Excellence, NCFPD sponsors Hatch and Lloyd’s participation in support of the organization’s overarching mission: to mitigate potentially catastrophic public health and economic effects of biological or chemical attacks on the nation's food supply.

“NCFPD looks at the vulnerability of our food system and works to reduce the possibility of contamination at any point along the food-supply chain," said Young. “Hatch and Lloyd’'s research plays an instrumental role in ensuring that no matter the stage of production: farm crops, food processing, transportation, or even food service, the food that we serve to our families each night is safe."