K-State researcher studying E. coli in beef
MANHATTAN, Kan. – Less than two years into a sweeping five-year study focused on prevention of Shiga toxin-producing E. coli in beef, researchers at Kansas State University and elsewhere are making progress on several fronts, according to Randy Phebus, K-State professor of animal sciences and industry.
“We’ve already done some beneficial research,” said Phebus, who added that scientists are working closely with industry production and processing partners because it’s important to study the problem in real-life settings.
The $25 million effort announced two years ago includes more than 50 collaborators across the country, including 14 universities and government agencies. Seventeen K-State scientists are working with the lead institution, the University of Nebraska, and others on a multi-pronged approach aimed at reducing the occurrence and public health risks from Shiga toxin-producing Escherichia coli (STEC). This group of bacteria is a serious threat to the safety of the food supply, causing more than 265,000 infections in the United States each year. Eating contaminated food or direct contact with fecal matter from infected cattle and other ruminants causes most of these illnesses.
“I think this is really ground-breaking work that we’re doing,” Phebus said. “It’s work that hasn’t really been done elsewhere just because of the scope of it.”
The part of the study K-State is focused on has several objectives, said Phebus who is the lead K-State researcher on the effort.
Objective 1 involves improving detection capabilities. “There are over 200 strains of STEC, but we’re looking at the eight strains that USDA considers adulterants in raw beef and ground beef,” he said.
Objective 2 has a team studying the biology and ecology of these organisms in the beef production environment. “Where do they hang out?” said Phebus. “What makes cattle become positive (for STEC)? How does it get transmitted to the meat?”
Objective 3 is the portion that Phebus leads directly. “This team is examining intervention technologies where researchers are looking at anything pre-harvest, post-harvest and even at the consumer level where we can control E. coli using current technologies such as lactic or peracetic acid washing of carcasses,” he said. “The issue is that we don’t know how well these technologies that the industry’s already using, work against these new strains of E. coli. We have a better understanding of how they work against E. coli O157:H7, another potent STEC strain that scientists have been studying for several years. Plus we’re working on developing new antimicrobial technologies.”
Objective 4 involves what the team calls quantitative microbial risk assessment, Phebus said, which includes gathering all of the data coming out of the various research efforts plus data from other studies “so we can quantify and predict how well certain strategies work versus others.”
Objective 5 is all encompassing and involves the outreach component, he said. Through educational modules, presentations, publications and other methods, the researchers will inform and educate the public, including beef producers and processors, about the findings of the various studies.
“A big part of our grant is to look at how we can reduce the risk of these pathogenic E. coli strains in foodservice and consumer situations. That’s where education and human behavioral interventions come in,” said Phebus, adding that there’s a big need for consumer education when it comes to the proper storage, handling and cooking of food.
Studying live cattle and processing sectors
“We’ve done a ground beef study in a large beef processing plant already and will repeat it early next year,” Phebus said. “We’ve also completed a study looking at sausage manufacturing.”
In a specially outfitted space at K-State’s Biosecurity Research Institute, team members are investigating how electrostatic spray technology can efficiently deliver food-grade antimicrobial solutions as a whole carcass treatment to control STEC and other meat-borne pathogens. Electrostatic technology puts a fog of chemical into the air that’s charged and then is uniformly deposited onto all oppositely charged carcass surfaces.
“The technology works because it gives good coverage but also allows us to use chemicals that would be too expensive to use as a high-volume wash,” Phebus said. “It also uses far less water than a wash does, which would be a huge bonus for (beef) plants in some parts of the country such as the Midwest if it’s effective.”
The researchers are also examining possible interventions in live cattle, including trying to determine the prevalence of these STEC organisms prior to harvest, he said. “We’re looking at what impacts the organisms at different times of the year and in different management systems at the feedlot level.”
“We completed a big project this summer that looked at fecal and hide samples and then corresponding carcass samples to try to follow the STEC contamination from the live animal through processing,” he added.
Phebus said that while researchers are making headway, there’s more work to be done: “The minute you answer one question, you have 10 more questions to answer. It’s an evolving process.”
–K-State Research and Extension