Stopping E. Coli 0157:H7 in its Tracks
Interventions and practices against one of the most lethal pathogens continue to emerge along the farm-to-fork chain.
If putting up hurdles against pathogens was an Olympic event, the U.S. beef industry likely would earn a medal. Beef producers and processors have made major strides in reducing the prevalence of and illnesses relating to one of the most deadly organisms, Escherichia coli O157:H7.
Today, a dozen years after tainted ground beef linked to Jack-in-the-Box restaurants caused a rash of illnesses and deaths in the Pacific Northwest, an array of measures have proven effective against the spread and transmission of E. coli bacteria. Figures released in April by the Centers for Disease Control and Prevention (CDC) indicate infections from E. coli O157:H7 have dropped 42 percent since the baseline years of 1996 through 1998. During that same time period, the Department of Agriculture (USDA) reported a sustained decline – up to 43 percent – in positive samples of E. coli O157:H7 in its ground beef sampling program.
James O. “Bo” Reagan, vice president of research and knowledge management for the Centennial, CO-based National Cattlemen’s Beef Association (NCBA), relays the industry’s effort also was reflected in the recent “Healthy People 2010” report compiled by the CDC, USDA, and the Food and Drug Administration (FDA).
“They came out with a recommendation to reduce E. coli O157:H7 infectivity to less than one per one-hundred thousand population by 2010, and we’ve been able to meet that goal six years early. That is huge news,” he points out.
Indeed, the collective findings are significant, say industry experts. “The fact that we’ve reduced the incidence of E. coli O157:H7 in ground beef by about eighty percent over the last five years is a clearly a success story,” says James Hodges, president of the American Meat Institute Foundation (AMIF), Washington, DC, which has spearheaded many initiatives since the pathogen first emerged on the industry radar in the late 1980s.
The accomplishments were not flukes, Hodges relays. “The reason for that success is largely a tribute to the dedication and perseverance of the industry to reduce the prevalence of bacteria on the carcass and to prevent the introduction of the organism into the plant from the live animal,” he adds.
On the front lines at the plant level, processors agree that collaborative industry measures have worked, especially those that have been implemented in the short term. “We have learned more and done more in the last three years for overall understanding and implementation of food safety strategies than in the past twenty years,” remarks Sharon Beals, director of food safety and quality assurance for Springdale, AR-based Tyson Fresh Meats. “[National food-safety expert] Dr. Mike Doyle recently stated that ‘the beef industry has done just about all it can do’. Although a powerful statement, and also somewhat gratifying considering the amount of resources and capital that we have committed, we recognize the need to push forward for even more.”
When discussing ways to reduce or eradicate E. coli O157:H7, one point that has been repeatedly emphasized is that there is no magic bullet. “It is a combination of interventions and best practices working in concert that must be engaged continuously to achieve success in this pathogen reduction food safety arena,” points out Beals.
Matt Osborn, manager of research and development for Wichita, KS-based Excel Corp., agrees that weapons in the fight against this pathogen are best when aimed along the entire front. “This isn’t a three-hurdle thing – we have eight big hurdles and several smaller ones,” he says of systems in place at Excel’s beef plants.
As food safety has evolved to a true multi-hurdle approach, there also been an emerging and simultaneous focus on infrastructure in meatpacking facilities. Industry groups including NCBA, AMI, and the National Meat Association (NMA) have worked together with packers and processors to detail and help ensure industry-wide standards through best practices, including practices at the plant level. Such steps, including SSOPs (Sanitation Standard Operating Procedures), HACCP (Hazard Analysis & Critical Control Point) programs, and other measures that have already been in place for years, span the operations of slaughter, fabrication, and grinding. “That has really snowballed,” says Reagan of best practices compliance. “Well over ninety percent of beef in the U.S. is harvested in plants that follow those best practices, and eighty percent of ground beef comes from those plants.”
It is important to distinguish between best practices and interventions, Beals says. “As a rule of thumb, unless we see a greater than one-log reduction capability under actual plant operating conditions on a consistent basis, we do not use the term ‘intervention’ but rather term such a process or activity as a ‘best practice’,” she explains. “Therefore, a successful food-safety program platform is based on the multiple-hurdle approach supported by numerous best practices and then strengthened by key interventions applied to the carcass or product.”
Although practices and interventions are in place across the supply chain, there is a literal beginning point. Pre-harvest measures have been a focus of industry attention over the past few years.
“One focus area has been hide cleaning, and the other things we are looking at more are probiotics and vaccines,” reports Reagan.
Hodges agrees that working upstream is important. “There are interventions now being used in the live animal, particularly vaccines and probiotics, that reduce the quantitative level of bacteria carried into the packing plant. We then have a greater probably of preventing it from being transferred to the carcass,” he says.
As it is on the farm or feedlot, eliminating contaminants on the hide is a priority at meatpacking plants. For example, the first step in a six-step intervention process at plants run by Greeley, CO-based Swift & Co. is hide washing, says spokesman Jim Herlihy. “Live animals are the source of contamination, primarily from the hide. Hide washing reduces the incoming microbial load,” he explains.
Excel also has made improvements to its hide-on carcass washes. “We not only installed hide-on carcass washes, but are working on optimizing their effectiveness and driving them to a higher level of performance. The focus is on what tools can be used to make it better,” Osborn says.
Down the line, carcass washing and sanitizing has proven critical as well. In its 11 beef slaughter and processing plants, Tyson has implemented several carcass treatments that fall under intervention and best practice steps, including SPS-steam, hot water final wash, engineered carcass wash systems, Sanova (antimicrobial) post final rinse, PECS-lactic, PECS-Sanova (antimicrobial), PECS-Hot, organic acids, and steam vacuums.
Many of Swift’s sequential intervention steps are also related to carcass treatment. For example, after hide washing, areas of beef surfaces contacted by knives or machines during the skinning process undergo steam vacuuming, a step followed by a patented pre-evisceration wash using water and organic acids. After evisceration and splitting, carcasses pass through a pasteurization chamber. “This is lethal to E. coli O157: H7 and other pathogens and further cleans the product,” notes Herlihy, adding that a thermal organic rinse and cold carcass sanitizers are conducted prior to disassembly of the carcass into subprimals and trimmings.
Those are just a few examples of the numerous interventions that have been developed in the past few years alone that specifically target E. coli O157:H7. Other packers have invested in different types of interventions, ranging from antimicrobials applied to beef trimmings and food contact surfaces to the use of irradiation on final packages of ground beef. Indeed, there is no one-system-suits-all solution.
“What may be applicable in a certain plant based upon their operation and types of animals they are processing may work better than in another plant,” observes Hodges.
Testing and more testing
As important as interventions are, they all had a genesis. To that point, research on E. coli O157:H7 continues at universities around the country, sponsored by industry groups, processors and independent meat scientists alike. Among some of its recent projects, AMIF is funding studies on how to reduce E. coli O157: H7 in cattle drinking water, how to improve testing for ground beef, and how to use the latest antimicrobial treatments for primals and trimmings before beef goes through the grinding process.
Testing isn’t limited to university research, of course. Packers and processors are constantly evaluating ground-beef products in their own facilities and through third-party laboratories to detect the presence and level of E. coli O157:H7.
“More recently, there has been an emphasis on looking at various testing procedures in ground beef,” agrees Hodges. “That has helped highlight or verify the effectiveness of many of the things we are doing, and it extends from the live animal all the way through the ground beef.”
Thanks to new technologies, testing for E. coli O157:H7 is becoming both more accurate and faster. Several kits and assays are available, with some results available in a matter of a few hours. “A statistically valid and robust E. coli 0157: H7 sampling plan, designed to detect low levels of the pathogen and remove affected material from the raw product stream, is applied to one-hundred percent of beef raw materials that are destined for ground beef,” says Beals.
Finally, while practices, interventions, and research have made a considerable dent in the E. coli problem, it is not a time for producers and packers to rest on their laurels. As recently as April, industry leaders came together through a food-safety summit to discuss future measures to keep beef safe from E. coli O157: H7.
“The leaders came in, sat down for a day-and-a-half, and went though each of the best practices and updated them – ‘what did we learn the last two years?’ and “what else do we need to add to that?’” Reagan says.
Herlihy agrees that while the steps currently in place are solid, it is no time to be complacent about this infamous pathogen. “The industry is at somewhat of a plateau – having made huge strides against E. coli,” he points out. “What remains is fine-tuning of processes as the industry continues to add incremental measures of effectiveness to existing E. coli protocols.” NP