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When a food recall due to E. coli O157:H7 or other food-borne
pathogens, like Salmonella or Listeria, grabs the headlines – it
can shake consumer confidence in food products, which doesn’t
bode well for the beef industry.
So, do ranchers have any ability to help enhance the safety of
the beef they produce and help minimize the incidence of
food-borne illness in beef?
Absolutely! Beef industry experts say that food safety starts at
the ranch.
John Scanga, who has done extensive research on red meat safety
and meat quality as an Extension meat scientist with Colorado
State University, explains, saying,“E. coli O157:H7 is a
pathogen that is prevalent across all environments, so an
integrated approach from cow-calf to the packing plant to the
consumer is necessary to help combat food-borne illness.”
Why is the ranch a logical place for pre-harvest control of E.
coli?
Because the majority of U.S. cattle are handled by only a few
packers, the industry has implemented food safety intervention
strategies at that sector since they are easier to universally
employ, explains Scanga.
Hazard Analysis Critical Control Points (HACCP) at the packing
plant include a multi-faceted system of interventions to kill
pathogenic organisms on the carcass such as steam vac, thermal
pasteurization, pre-evisceration wash, and an organic acid wash.
However, while those methods have offered improved success,
foodborne pathogens like E. coli O157:H7 continue to plague the
meat industry. Thus, new emphasis is being placed on additional
intervention strategies to reduce food-borne pathogenic
bacterial populations in the live animal prior to slaughter.
“What we’ve learned about the E.coli O157:H7 organism is that it
is really transferred from animal to animal, through water,
nursing calves, etc.,” says Scanga. Therefore, he says there are
a number of preharvest pathogen controls at the cow-calf level
and at the feedlot that may help reduce the incidence of
food-borne pathogens.
What are some specific management practices to help reduce
foodborne pathogens at the cow-calf level?
Scanga cites research on two vaccines currently being field
tested, as well as research on feeding probiotic supplements to
reduce E. coli O157:H7 in the fecal matter of cattle.
Additionally, Scanga suggests management practices such as water
tank sanitation and providing dry areas for cattle may aid in
reducing food-borne pathogens. Biosecurity steps with feed may
also be beneficial. For instance, using two different loaders to
move manure and handle feed to prevent cross-contamination.
How do
probiotic supplements
work?
West Texas A&M epidemiologist Guy Loneragan explains that
currently, Nutrition Physiology Corp. offers a product called
Bovamine, which is the most widely studied probiotic product and
on average has been shown to decrease the percentage of cattle
testing positive for the E. coli O157 organism by 40 to 60%.
Loneragan says, “It clearly works, but it does not have a
label-claim for reducing E. coli O157.” To be effective, the
probiotic needs to be fed every day, so would be best suited to
confined animals.
Another supplement product is Sodium chlorate. This chemical
gets converted by certain bacteria, including E. coli O157 and
Salmonella, to a toxic substrate, explains Loneragan. It can be
developed to be delivered in feed or water and holds great
promise, he says, and reports that a company is currently
sponsoring it through the FDA approval process. So it is hoped
that if all goes well, it will be available soon.
Another product being studied are specific strains of
bacteriophages, which have been shown to prey on certain
pathogens like E. coli O157, according to Loneragan. Certain
bacteriophages have already been approved for application to
tomatoes, and ready-to-eat products for Listeria, as well as to
the surface of cattle for E. coli O157. “If these could be
developed on a commercial scale for oral administration to
cattle, it would be of great interest,” Loneragan says.
What about
vaccination?
Is that available?
Presently, Bioniche Animal Health and Epitopix – which has a
cooperative agreement with AgriLabs – are in various stages of
field trials and requesting a license for special vaccines
developed to reduce shedding of E.coli O157:H7 [both companies]
and Salmonella Newport [Epitopix]. Loneragan calls these
“extremely promising products,” and says the advantage of a
vaccine is that it could be used in a variety of production
settings and fit into normal procedures.
Bioniche has just recently received a Permit to Release
Veterinary Biologic in the U.S., which is a restricted
conditional license to make it available.
Of the vaccine Loneragan says, “The product clearly works across
a significant number of field trials and these data have been
published and are compelling.” Loneragan adds that with the
approval of the first license, it should facilitate the
licensing process for other companies such as Epitopix.
What advice should ranchers heed as these new technologies
become available for combating pathogens like E.coli and
Salmonella?
Loneragan admits that none of these technologies alone will be a
silver bullet for the industry, but each represents a hurdle in
a multi-hurdle approach.
For example, Loneragan says, “Continued use of probiotic
supplements like Bovamine is important but adding vaccines to
certain situations or sodium chlorate before harvest will add
hurdles that enhance beef safety at harvest and beyond.”
He says, “The goal is that efficacious preharvest interventions
will decrease the percentage of cattle carrying E. coli O157
into plants; and decrease shedding into the environment and the
opportunity for reinfection. These latter aspects of control are
extremely valuable.”
Loneragan also emphasizes that different intervention
technologies are needed so that they can suit varied production
practices. Of the products outlined above he says, “These are
all slightly different and some may be better suited to
different production settings.”
Given the increased number of beef recalls due to E. coli O157
in 2007, Loneragan says it is critical that these preharvest
interventions gain approval and begin to be applied within the
industry.
“The industry is committed to eliminating this pathogen partly
so we are not saddled with these recalls, but most importantly,
it will be an important aid in helping producers supply
consumers with the safest possible product,” Loneragan says. |
