This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the October 1, 2018 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
Last month’s column discussed how antibiotics are used in Western Canadian cow-calf operations. Respiratory diseases are a common reason for antibiotic treatment in cows, bulls, and calves and diarrhea is a common reason for antibiotic treatment in young calves. Because both respiratory and intestinal infections can involve many different microbes, having a better understanding of what microbes may be causing a particular animal to be sick could allow more appropriate treatment decisions. For example, antibiotics don’t kill viruses, so using antibiotics won’t help an outbreak of scours that is primarily viral in nature. Similarly, some antibiotics are more effective against some bacteria than others, so being able to select the antibiotic that is most appropriate for the bacteria that are involved would be helpful.
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the November 2016 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
There are between 50,000 and 100,000 different serotypes (strains) of E. coli. Most are harmless, some may be beneficial, but some produce a very dangerous Shiga toxin. Shiga toxigenic E. coli (STEC) can cause vomiting, diarrhea and abdominal pain in people.?E. coli O157:H7 is the most well-known STEC, but it is not the only one.
All STEC’s carry at least one stx gene coding for the Shiga?toxin, an eae gene coding for a protein that helps E. coli attach to the intestinal surface, and a wzx gene that codes for an “O” antigen. All three of those genes must be present in the E. coli cell for it to be a STEC.
Food safety risks due to E. coli O157:H7 are well known, and the beef industry has made great progress in controlling it. Non-O157 STEC infections are rarer, but in 2011 Continue reading
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the April 2016 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
The muscle tissues of healthy animals are essentially free of bacteria until carcasses are skinned. At that point, it is impossible to eliminate the transfer of bacteria from the hide and the environment to the meat.
Many of those bacteria are harmless, but some can cause meat to spoil faster. Others, like verotoxigenic E. coli (e.g. E. coli O157:H7 and others) can pose a very serious risk to human health. Well-managed packing plants can minimize the transfer of bacteria from the animal to the carcass, but they can’t eliminate it completely. Many food safety interventions such as Continue reading
Consumer Reports Food Safety and Sustainability Center released its “Beef Report” on August 25. A number of questions, concerns and criticisms have been raised by the North American Meat Institute, the International Food Information Council, Business Insider, and others. Rather than answer the specific questions raised, Consumer Reports has encouraged people to read the report more closely.
Unfortunately, reading the report more closely simply raises more questions about the expertise and/or integrity of Consumer Reports and its “policy and action arm,” Consumers Union.
Here’s one example.
“The Danger of Superbugs” heads a section on Page 10 and 11 detailing the health hazards posed by Shiga-toxin producing E. coli (STECs, like E. coli O157). This directly implies that antimicrobial resistance will make STEC infections more difficult to treat. This is not true.
Antibiotics are not used to treat STEC infections in people. Instead, Continue reading
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the March 2015 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
Combating bacteria would be simple if they stayed on the surface of beef. In that case, nearly any spray or wash could contact and kill the bacteria or wash them off. But beef isn’t smooth. Shallow cuts and cracks crisscrossing the meat surface can hide and protect bacteria. Killing these hidden bacteria is not simple. Irradiation would work, but isn’t approved for use in Canada yet. Organic acid washes and sprays may not reach the bacteria hidden in these cracks, or the acids may be neutralized by the meat proteins before bacteria can be killed. To kill these bacteria, food safety interventions need to penetrate a short distance into the meat surface. This is particularly important for beef trim (the small pieces of fat and meat that are removed as the carcass is processed into smaller cuts) that is used for hamburger. The late Dr. Colin Gill of AAFC Lacombe showed that exposing beef trim to extremely hot water essentially “cooks” the top few millimeters, and kills up to 90% of bacteria.
This raises an interesting dilemma. Consumers want safe beef, but they also Continue reading
Recent work has shown that E. coli can essentially be eliminated from dressed carcasses in commercial packing plants. Carcass chilling processes can be operated to supplement or largely substitute for decontaminating treatments. Machinery and personal equipment can be cleaned and used in ways that prevent such equipment from contaminating meat during carcass breaking. As a result, food safety issues with beef may arise if known best practices and treatments and practices necessary to produce cuts and trimmings free of pathogenic E. coli and Salmonella are incompletely or inappropriately implemented.
Research currently underway and funded by the National Check-off and Canada’s Beef Science Cluster is working to identify which Continue reading
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the October 2014 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission of the publisher.
All food surfaces carry bacteria, including steaks and roasts. Because beef cooks from the outside in, the outer surface is exposed to higher temperatures for a longer time than the inside of the beef. The heat of cooking will inactivate bacteria as long as they remain on the outside of cuts, and the surface is cooked thoroughly. That’s why steaks and roasts can be eaten rare. In ground beef, microbes from the surface get mixed throughout the beef, so consumers are encouraged to cook ground beef to an internal temperature of 71oC.
Mechanical tenderization pierces beef with small blades or fine needles. This cuts the connective tissue and makes the beef more tender. This improves the eating quality of lower cost, tougher beef cuts. Price and tenderness are two of the major drivers of consumer buying behavior and eating satisfaction, so mechanical tenderization has proven quite useful. Approximately 20% of Canadian beef is mechanically tenderized.
But if there are Continue reading
The food safety risks associated with E. coli O157:H7 are well established and the beef industry has placed a sustained effort in devising strategies to control it.
E. coli O157 is highly pathogenic due to its ability to produce Shiga toxin, among other virulence factors. In recent years, there is increased awareness that illness can also be caused by other Shiga toxin producing E. coli, collectively referred to as non-O157 STEC. In the U.S., the Top 6 non-O157 STEC have been given the same status as E. coli O157. Canada’s beef processing industry needs to be prepared to implement the appropriate testing and recall measures for these STECs, as the U.S. is Canada’s main beef export market.
Research currently underway and funded by the National Check-off and Canada’s Beef Science Cluster will Continue reading
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the February 2014 issue of Canadian Cattlemen magazine and is reprinted on the BCRC Blog with permission.
No one wants to throw up in zero gravity, so space programs take great care to avoid food poisoning among astronauts. Irradiation has been used to pasteurize astronauts’ food since 1966. In fact, irradiation has been the most studied of all food-processing technologies over the past 60 years. Irradiation improves food safety by fatally damaging bacterial DNA. This stops the growth and reproduction of the bacteria that can cause food to spoil or people to become sick.
Irradiation is also approved as a food safety treatment in over 50 countries back here on earth. For example, France, Belgium and the Netherlands use irradiation to combat food-borne pathogens in frogs’ legs, seafood, and poultry. The U.S. has approved irradiation of meat. Canada has approved irradiation for spices, seasonings, flour, onions and seed potatoes, but not meat or poultry. Irradiation is safe for human food use at doses more than eight times higher than those approved for meat in the U.S. Irradiation does not cause the meat to become radioactive, and has less of an effect on food nutrients than cooking does, but irradiation can have undesirable effects on flavour or colour under some conditions. Continue reading
This article written by Dr. Reynold Bergen, BCRC Science Director, originally appeared in the January 2014 issue of Canadian Cattlemen magazine and is reprinted with permission.
The last two research columns have been about technologies and best practices that large and small beef packers can adopt to avoid bacterial contamination during dressing of beef carcasses, and to avoid bacterial (re)contamination of beef cuts and trim during further processing. Ground beef is more of a food safety risk than other cuts, for reasons discussed in last month’s column. As a result, Dr. Colin Gill, Xianqin Yang, Madhu Badoni and Mohamed Youssef of AAFC’s Lacombe Research Station have studied whether lactic acid sprays can combat E. coli in beef trim. Continue reading