Friday, October 19, 2012

Sustainability and On-Farm Antibiotic Use

The USDA’s Agriculture and Food Research Initiative (AFRI) released their definition of sustainable agriculture, which includes 5 goals and the actions needed to achieve those goals.

The term ‘sustainable agriculture’ (NARETPA, 7 U.S.C. 3103) means an integrated system of plant and animal production practices having a site-specific application that will over the long-term achieve the following goals:

  1. Satisfy human food and fiber needs;
  2. Enhance environmental quality and the natural resource base upon which the agriculture economy depends;
  3. Make the most efficient use of nonrenewable resources and on-farm resources and integrate, where appropriate, natural biological cycles and controls;
  4. Sustain the economic viability of farm operations; and
  5. Enhance the quality of life for farmers and society as a whole. 

The National Research Council Committee on Twenty-First Century Systems Agriculture states “that progress toward these goals will require robust systems which adapt to and continue to function in the face of stresses, are productive, use resources efficiently, and balance all four goals…They further state that if the U.S. is to maintain adequate resources to meet food, feed, fiber, and biofuel needs, progress toward meeting the four goals must be accelerated. This acceleration must be based on research that determines ways to reduce tradeoffs and enhance synergies among the four goals while managing risks associated with their pursuit” (USDA/NIFA, 2012).

Antibiotic use in the food animal industry has been shown to increase growth, efficiency, and safety while decreasing economic costs. Compared with these guidelines, antibiotic use in food animals is also productive, uses resources efficiently, and maintains resources to meet food needs. Lastly, antibiotic use in food animals is a perfect example of a research-based method that reduces tradeoffs and manages risks. Although there are some inherent risks in using antibiotics in the food animal industry, the risks and tradeoffs associated with removing them (disease spread, unsafe food supply, carcass contamination, etc) are far outweighed by the benefits of continuing responsible, carefully monitored use.

So, are antibiotics an essential part of “sustainable agriculture”? I believe so.

United States Department of Agriculture/National Institute of Food and Agriculture (USDA/NIFA). (2012). Agriculture and Food Research Initiative Competitive Grants Program.

Monday, October 15, 2012

Controlling E.coli

Early in October, an article was published on by a food-industry journalist who stated that E. coli 0157:H7 is impossible to monitor or identify. Along with Dr. Guy Loneragan (Texas Tech University) and Dr. David Renter (Kansas State University), I wrote a response to the article which explains and cites scientific evidence refuting the journalist’s statements.

The article can be found here: Scientists respond to Murphy’s E. coli commentary

Friday, October 12, 2012

Recalling Moderation

The ongoing recall at Canada’s XL Foods, Inc. inspired by E. coli O157:H7 continues to grow. As a result, many media outlets are giving the public the impression that this recall is due to a massive breakdown in the “food safety system.” This interpretation is a bogus hyped-up media frenzy inspired by minority politics and folks looking for a law suit. (1) Gosh, it feels good to be able to say what I feel! After 13 years in USDA, one of those years in a political appointment, it is still difficult to do. During my first week on the job as Deputy Undersecretary for Food Safety (USDA), our agency implemented the largest meat recall in US history (>145 million pounds) due to evidence that Hallmark foods in Chino, CA had harvested downer cows without additional USDA inspection. I have some experience with a sense of “recall hysteria.”(2)

The true facts of a recall must be understood so that people are not afraid to eat! It is terrible when people get sick or die from preventable diseases. Certainly, it is troubling when everyday a new food company announces that they are recalling their product; for example, peanut butter or beef. It is worse when we have one of these “rolling recalls” where the bad news keeps coming. But the news does not always match the true public health impact. As of October 15, fifteen cases of illness and ZERO deaths have been associated with the XL Foods recall.(3) If companies screw up they should fix it, but that does not mean the “whole system” is broken.

These messy “rolling” recalls happen as investigations into the source of the illness uncover new information, particularly information about the “cause” of the recall and how long ago this “cause” started. Note that a recall does NOT mean that product is for sure contaminated. It only means “in an ‘abundance of caution’ there is a chance the product could be contaminated, therefore it is better to pull it off the shelf”. Sorry, I almost sounded like a government guy again.

The peanut butter recall is growing as companies check their records and find that they may have bought product from Sunland, Inc. or someone who sources from them. (4) Again, it does not mean the all peanut butter is contaminated, nor does it mean that Joey’s all natural PBJ sandwich from last week will be the end of him. (Joey is my dog, Joe-Joe, my grandson, and Joseph is my grandfather). On a practical note, it does mean that consumers should check their shelves and return recalled product. It means that we must constantly take ownership of our own food safety. We can keep eating, being thankful for another meal and a system that has the transparency to issue recalls when they needed, and enforce improvements when they are warranted.

(1)Murphy, D. 2012. Commentary: Playing the Blame Game.

(2)Food Safety and Inspection Service. California Firm Recalls Beef Products Derived From Non-Ambulatory Cattle Without The Benefit Of Proper Inspection

(3)Food Safety News. 2012. More illnesses in Canada Linked to Recalled Beef.

(4)Food Safety News. 2012. More Products with Sunland Ingredients Recalled.

Tuesday, October 2, 2012

Is antibiotic-free meat actually antibiotic-free?

Farm animals from conventional farms and antibiotic free farms both have strains of antibiotic resistant bacteria. In a recent study conducted at North Carolina State University, researchers found identical sequence types of the resistant bacteria Campylobacter coli (C. coli) isolates in pigs raised on conventional farms as well as antibiotic free (ABF) farms.(1) For those that think banning antibiotic use for food production will solve our resistance problems, this study is troubling.

Dr. Siddhartha Thakur collected thousands of samples from pigs and their surrounding environments over several years and performed tests on 200 strains of C. coli to see if those from ABF farms had similar resistance patterns as those using antibiotics.(3) They did.

This study could be interpreted in many ways: 1) antibiotic use does not make a difference in resistance populations, 2) the evil practice of antibiotic use on-farm is impacting ABF farms, 3) some of the ABF farms may have previously used antibiotics and more time is needed for this resistance to disappear, and/or 4) there is another source of resistance other than antibiotic use.

Dr. Thakur proposes 4) another source of resistance. Dr. Thakur’s two studies over several years indicated that the same antibiotic resistant C. coli bacteria were found on conventional and ABF farms. Because the pig populations had never come into contact with each other, Dr. Thakur concluded that the environment must be contributing to the antibiotic resistant bacteria. (2)

It should be noted that C. coli is unique relative to other types of Campylobacter because it is seen primarily in pigs and it has shown higher levels of resistance. Campylobacter is a leading cause of food borne illness in the United States and has been found in populations of swine, cattle, and poultry. However, cattle and poultry usually shed Campylobacter jejuni (C. jejuni), whereas swine are the main source of Campylobacter coli (C. coli).(1) The scientists at NC State attributed the higher resistance to higher frequencies of recombination in C. coli. Recombination in bacteria is a process in which genetic material is transferred between cells, which allows for fast movement of newly evolved genes.

"In the case of ABF pigs, the environment plays an important role in their exposure to these resistant strains," Thakur says. "If the environment itself, and not the pig, is serving as a reservoir for C. coli, then we will most probably continue to find resistant bacteria populations, regardless of a producer's antimicrobial use." (2)

If Dr. Thakur’s analysis and conclusion are correct, then on farm antibiotic use is unlikely to be increasing any human health risk to C. coli. However, the question of antibiotic resistance must be constantly evaluated on a case-by-case (bug-drug) basis.

1. Quintana-Hayashi MP, Thakur S (2012) Phylogenetic Analysis Reveals Common Antimicrobial Resistant Campylobacter coli Population in Antimicrobial-Free (ABF) and Commercial Swine Systems. PLoS ONE 7(9): e44662. doi:10.1371/journal.pone.0044662

2. 2012. Antibiotic-resistant pathogens persist in antibiotic-free pigs.

3. Gabbett, R. J. 2012. Research finds antibiotic-resistance in antibiotic-free pigs.

For those who think all I do is promote antibiotic use in livestock here is a news flash!

A paper was recently released by Dr. Scott Hurd and Dr. Sasidhar Malladi in Foodborne Pathogens and Disease. The paper, entitled 'An Outcomes Model to Evaluate Risks and Benefits of Escherichia coli vaccination in Beef Cattle', discusses the impact of vaccinating cattle for E. coli 0157:H7 on carcass contamination and food-borne illness.

The paper can be found at the link below.