Pathogenic bacteria, bovine spongiform encephalopathy (BSE), avian flu. You name a microbiological challenge faced by the meat and poultry industry in the past 40 years, and Dr. William Brown has seen it, analyzed it and researched the science-based solutions for it.
As president of ABC Research Corp., the Gainesville, FL-based ISO 17025 accredited, full-service microbiological and chemical food laboratory that he founded in 1967, Dr. Brown lends his expertise to a variety of food processing plants, retail and distribution companies, foodservice operations, trace associations and universities. During his more than four decades of experience in the food industry, Dr. Brown also held positions as vice president research at John Morrell & Co. and as an instructor at North Carolina State University. Among his many professional affiliations, Brown served on the U.S. Department of Agriculture (USDA) National Advisory Committee on Microbiological Criteria for Food, is executive director of the Southeastern Meat Association, and is a past member of the Technical Advisory Committee for the U.S. Poultry & Egg Association.
Dr. Brown spent some time with Food Safety Magazine to share his insights on some of today’s pressing issues faced by meat and poultry microbiologists and shares his recommendations on how to meet these and future challenges.
Food Safety Magazine: In your experience, Dr. Brown, what are the top food safety issues of concern to today’s meat and poultry producers and processors in terms of microbiological hazards?
Brown: There are three areas that I think are the top food safety issues in the immediate future. The first issue of concern to food microbiologists and the food industry is bacterial pathogens because we know that these microorganisms can cause illness and even death. The two most prominent pathogens of concern, and that certainly cause the most problems for the meat and poultry industry, are E. coli O157:H7 and Listeria monocytogenes. The second area of concern to meat and poultry producers, processors and microbiologists is viruses, specifically hepatitis A and the avian flu. The third issue that I believe will be important to address is prions due to their association with Mad Cow disease.
FSM: In terms of these issue areas, what kinds of developments are underway that will help the industry successfully address these challenges?
Brown: In terms of E coli O157:H7, there are a few things that will help. First, we need to take the testing from slaughter plant back to the farm. What I mean by this is that we need to test the animals to determine whether they are positive or negative for the pathogen before sending them to the meat packing plant. In terms of control measures that can be taken to reduce the incidence of E. coli O157:H7 at the farm level, there are a few developments that should help. One is the addition of probiotics to the feed that appears to help reduce the shedding of E. coli O157:H7. Also, there has been some recent Canadian research on vaccines that could be given to the animals on the farm to reduce shedding.
Since Listeria monocytogenes is a foodborne illness causing pathogen that is found literally everywhere, it is proving to be a difficult challenge for many types of food processing and handling operations. In addition, Listeria monocytogenes has a reputation for staying in a processing plant and continuing to be a source of infection. For example, we saw a Listeria strain that caused the death of a woman in Texas and eight or 10 years later, the same strain was found in the processing plant where the contaminated product was manufactured. Recently, some poultry trucks were checked for Listeria monocytogenes and the pathogen was found on 100 percent of them. This is a post-processing contamination problem that the industry really needs to work on.
In terms of regulatory developments, the USDA Food Safety and Inspection Service (FSIS) issued in 2003 an interim final rule, “Verification Procedures for the Listeria monocytogenes Regulation and Microbial Sampling of Ready-to-Eat Products for the FSIS Verification Testing Program,” which outlines some of the ways in which the industry can develop approaches to combat this pathogen. The interim final rule requires manufacturers of medium- and high-risk RTE meat and poultry products to develop written programs to control Listeria monocytogenes and to verify the effectiveness of those programs through testing. The rule establishes three risk-based alternatives for categorizing RTE products and encourages plants to install new technologies to eliminate or reduce the growth of Listeria monocytogenes. The rule also states that establishments must share testing data and plant generated information relevant to their controls with the agency.
With regard to viruses, our ability to detect and characterize these in foods is not as advanced as our ability to test for pathogens in foods. Improvements in virus testing will only come through increased emphasis at the basic research level at research laboratories. There are some basic research problems that need to be looked at, especially in the case of the avian flu. As we’ve seen, the avian flu has been picked up in a couple of poultry farms in Delaware, and very recently, the avian flu was found in a flock of poultry in Texas. Although the avian flu is not a new problem, in previous cases or outbreaks, we’ve been able to control and contain it. However, with the increasing population and travel between the U.S. and rest of the world, coupled with increased incidence of cross-contamination arising from people going back and forth between chicken farms, it is becoming a much more difficult and serious problem with which we must contend.
Hepatitis A is a problem with people not washing their hands after they go to the bathroom and the virus is passed on when these people handle foodstuffs. We know that the problem can be partially solved by requiring and implementing good personal hygiene practices and plant sanitation methods in food processing operations.
Meat microbiologists and the industry need to look at prions from a couple of standpoints. Recently, prions have been given a lot of publicity because of Mad Cow disease but they are also getting a lot of attention from researchers because they may also help us in the treatment of abnormal brain functions. There is some interesting information, for example, that has been published recently suggesting that prions may be involved in Parkinson’s and Alzheimer’s disease. The proteins are the workhorses of living things, and the human body probably makes about 50,000 different proteins for tasks ranging from building bones and muscle to digesting food and thinking. I think there may be an opportunity for researchers not only to solve the Mad Cow disease problem but also some of the brain function problems in our elderly population that are being reported.
FSM: What kinds of methods are being used to advantage by today’s meat and poultry microbiologists in terms of pathogens and viruses?