This past summer, Kathy Glass and her team made batches of pepperoni in her laboratory-cum-kitchen in the Microbial Sciences Building. But it would have been a very bad idea to put her handiwork on top of a pizza. Stuffed into each casing, along with pork and spices, were E. coli bacteria, the kind that make people sick — and sometimes die.
Glass manages the UW–Madison Food Research Institute’s Applied Food Safety Laboratory, where it’s common practice to add dangerous bacteria and fungi to all sorts of processed foods. When her team is not lacing pepperoni with E. coli, they make contaminated cheeses and other deli meats, all in the name of protecting human health. The tainted foods help Glass study how foodborne pathogens spread through the nation’s food system and search for ways to stop them.
One needs only to look at the headlines to understand the importance of that quest. Foodborne illnesses sicken approximately 76 million people in the United States each year, and kill about 5,000. The E. coli bacterium, while not one of the top offenders, is particularly deadly; just a few stray cells can kill. One of the worst incidents occurred in 1993, when a particularly dangerous strain of E. coli, known to scientists as O157:H7, contaminated hamburgers sold by the Jack in the Box chain, killing four people and sickening more than 700.
Glass and other scientists have been able to come up with ways to prevent contamination from the 0157 strain in meat processing. But in recent years, other, less-familiar types of E. coli have emerged. Public-health officials believe that these strains may account for 20 to 30 percent of all E. coli contamination cases nationwide.
Naturally, the meat industry is concerned, and that’s why Glass is preparing bad meats. The Grocery Manufacturers Association (GMA), which represents hundreds of food, beverage and consumer products companies across the nation, has funded Glass’s project to study the emerging strains to assess how they fare under different food-preparation conditions.
We are here to help food companies make their food products safe for the consumer. We really do work together for a common goal, which is public health.
— Kathy Glass
“This is a pre-emptive strike,” says Glass. “We want to find out if all of these new types of E. coli act the same way as the O157 strain. If so, or if they are more sensitive to processing, then we’re OK. But if we find out that these strains end up being more resistant to heating, that means we’ve got a lot of work to do [to figure out how to kill them].”
Glass has been in charge of the Applied Food Safety Lab since joining the Food Research Institute (FRI) in 1985. The institute has nine core investigators who are dedicated to understanding and solving problems related to microbial foodborne pathogens and toxins. Originally founded at the University of Chicago in 1946, the institute has been at UW-Madison for the past 43 years.
Among the institute’s labs, Glass’s is unique. Crammed with pilot-scale food processing equipment — from milk pasteurizers and cheese-making vats to meat slicers and shrink-wrapping equipment — it is a place where food companies come to get help dealing with specific contamination problems. The FRI is one of few academic institutions in the nation to help businesses in this way, says Glass. The results of the current E. coli study, for instance, will be distributed widely throughout the meat industry, including the state of Wisconsin, which is home to 488 meat processors and one of the largest producers of pepperoni in the nation.
The food-processing equipment allows Glass to make a wide variety of processed meats and cheeses just as the food industry would. Except for the nasty microbes they contain, the lab’s products are indistinguishable from comparable items available on grocery store shelves.
“We’re able to make foods with contamination that mimic what might happen in the real world, and because it’s more representative of what would happen in the real world, we’re giving people more accurate results,” says Glass. “It’s a shorter distance from the basic science to the application in the real world. That’s where we are. We’re that bridge.”
That is a big reason why the GMA chose UW-Madison lab to run the current E. coli study. Originally, GMA scientists had considered doing the project in-house, but they quickly realized this wasn’t an option. “First off, we don’t have a smoke house, and you can’t do pepperoni without one,” says Elena Enache, a GMA microbiologist who spent the better part of two weeks in Madison this summer working elbow-to-elbow with Glass’ team. “At the FRI lab, we mimicked the whole process. Everything was done like in the pepperoni industry.”
It also didn’t hurt that Glass ran the original E. coli O157:H7 safety study in fermented meats in the early 1990s, and that the FRI team subsequently developed the processing techniques that are still used today to kill O157:H7 in fermented meats.
Glass claims she hasn’t had a single boring day over the years. She has worked with a long list of companies, food products and pathogenic bacteria, calling upon her FRI colleagues to help whenever it made sense. Most projects involve testing the safety of new product formulations or re-evaluating products when new pathogens crop up. In recent years, Glass has been involved in a big push to discover natural antimicrobials that can compensate for the salt — a natural microbe-killer — that’s removed from low-sodium processed meats. “We go where there’s the greatest need,” says Glass, “and that’s a shifting target all the time.”
At present, the FRI has more than two-dozen dues-paying industry members that help guide the institute’s research agenda, including Wisconsin’s Johnsonville Sausage, Jones Dairy Farm, Sargento Foods and Schreiber Foods. But the institute is open to research projects proposed by members and nonmembers alike. On more than one occasion, a project has kept a business from failing. Some have helped save lives.
In one particularly fruitful collaboration, the FRI collaborated with Oscar Mayer to show that adding sodium lactate to processed meats was a safe way to prevent the growth of Clostridium botulinum, the bacterium that causes botulism, and, more recently, Listeria, a deadly bacterium that thrives in these products at refrigerator-temperature.
“Now you can’t find a processed meat product today that doesn’t have sodium lactate in it, and you can say that is because of a combination of work between FRI and Oscar Mayer,” says Larry Borchert, who was director of central research and regulatory affairs at Oscar Mayer from 1980 until his retirement in 1996, and oversaw Oscar Mayer’s role in the project.
While Glass is particularly proud of this project, it’s just one of many that have helped her lab fulfill its mission over the years.
“We are here to help food companies make their food products safe for the consumer,” says Glass. “We really do work together for a common goal, which is public health.”
Written by Nicole Miller