The Fight for Safer Food

To confront the threat of persistent foodborne pathogens, Steve Bowden turns to novel techniques to understand and take down those threats.

By Kyle Wong

Nearly one in six Americans suffer from foodborne illnesses each year, according to the Centers for Disease Control and Prevention (CDC). Scientists like the University of Minnesota’s Steve Bowden are working to change that.

Standard food-safety processes like pasteurization, freezing, and fermentation kill foodborne pathogenic bacteria, but these pathogens evolve to survive. Through mutation and the acquisition of new genes, pathogens can cause outbreaks from unfamiliar sources such as fresh produce, spices, and peanut butter. Bowden, an assistant professor in the Department of Food Science and Nutrition and a member of the BioTechnology Institute, is developing strategies to eliminate new and persistent pathogens.

One common offender is Salmonella, a bacterial species that infects millions of Americans each year, leading to thousands of hospitalizations and hundreds of deaths. Bowden studies how Salmonella responds to stresses in the food environments where it thrives. He seeks to identify common genetic traits that enable Salmonella to survive and grow under varied conditions. Ultimately, he hopes to develop procedures that eliminate harmful bacteria from the food system. “We want to understand why certain outbreaks occur in specific types of food and if there is a correlation with the genes found in those specific types of bacteria,” says Bowden.

To target specific foodborne pathogens, Bowden’s lab engineers a type of virus called a bacteriophage that infects and then kills bacteria. But identifying phages that work is only half the battle. Because pathogens are so diverse, effective treatment requires the right combination of phages to remove all of the pathogen targets and ensure food safety. To make things more complicated, the food matrix can also affect the phage’s efficacy. One cocktail of phages might succeed on one food but fail to remove the same pathogen in another.

Nonetheless, the Food and Drug Administration (FDA) has approved some phage cocktails. They are entirely harmless to humans and assist in the control of foodborne pathogenic bacteria during food processing. Their potential use as a safe, natural method to improve food safety is garnering interest in the food industry. Still, further research is required to enhance their efficacy and improve manufacturing methods.

Despite these challenges, Bowden’s longstanding fascination with molecular biology and microbiology keeps him motivated: “I was surprised by how many foodborne illnesses there are. I want to make use of genome sequencing to try and control these pathogens. What’s interesting about molecular biology is how we can apply it to make the world safer.”

Bowden’s drive to understand foodborne pathogens couldn’t have come at a better time. Addressing global threats to food safety, such as climate change and antibiotic resistance, requires broad thinking and a flexible approach. Bowden brings a global perspective to his work. After earning his Ph.D. in biochemistry at the University of Cambridge, he worked as a postdoc in the United Kingdom and Japan. “I feel lucky to have been in so many labs and learn different perspectives,” he says. “It’s helped broaden my appreciation for different ways to do research.”

The experience helped prepare Bowden for his research at the University of Minnesota. “The drive to understand a problem and develop techniques to study that problem has kept me in academia,” he says. “I’m excited to see what direction it takes.”

Kyle Wong is a writing intern in the University of Minnesota Science Communications Lab, majoring in Microbiology. He can be reached at wong0511@umn.edu