Agricultural antibiotics do have role in drug resistance, says CDC

CDC said it is difficult to directly compare the amount of drugs used in food animals with those used in humans, but there is evidence that more antibiotics are used in food production.

The Center for Science in the Public Interest (CSPI) said that the report shows that drug-resistant hazards in the food supply pose a serious threat to public health.

One-third of the twelve resistant pathogens that CDC categorized as a “serious” threat to public health are found in food​.

CSPI added that it while the CDC said antibiotics for growth promotion in food animals should be “phased out”, it was a “missed opportunity​” to advise veterinarians and federal and state agencies on reducing the quantity of antibiotics used in animal production.

Foodborne problem​

Four are foodborne organisms that become drug-resistant as the foods that carry them are produced or grown - Campylobacter, E. coli, Salmonella and Shigella.

Clostridium difficile and Staphylococcus aureus show some information at coming from farms but in this context are more of a healthcare issue, explained Dr Chris Braden, director of division of foodborne, waterborne and environmental diseases.

“Antibiotics in agriculture are an important contributor, no matter where they are used, it has to be necessary in order to treat infection in the animals. ​

“Salmonella and Campylobacter are the main ones in the food context but we have to prevent infections to begin with.”​

Antibiotic prescription​

Antibiotics are mostly used as prescribed drugs used in human medicine but are also given to food animals to prevent, control, and treat disease, and to promote their growth.

“CDC found that 22% of the resistant illnesses are linked to foodborne hazards, so the overuse of antibiotics in the animal sector can no longer be ignored.” ​said Caroline Smith DeWaal, director of food safety at CSPI.  

“The volume of antibiotics sold for use in animals dwarfs those used in human medicine.”​

Threats assigned to the urgent and serious categories require more monitoring and prevention activities, whereas the threats in the concerning category require less.

“The concern with the resistant organisms emerging from agriculture has never been that they are more virulent or more infectious than the resistance which emerges under the pressure of antibiotic use in medicine,”​ said Maryn McKenna in a blog.​

“Rather, it is that it is a bad idea to encourage the movement of any additional resistance DNA into the microbial traffic that makes up our world — because we have no way of knowing where that resistance will go, or in what bacteria it will end up.”​

Action before it’s too late​

The threats in the CDC report are ranked in categories: urgent, serious, and concerning.

“​But one of the reasons we're issuing the report now is that it is not too late. If we're not careful, the medicine chest will be empty when we go there, to look for a life-saving antibiotic for someone with a deadly infection,​” said Dr. Thomas Frieden, the CDC’s director.

They were assessed according to health impact, economic impact, how common the infection is, a 10-year projection of how common it could become, how easily it spreads, availability of effective antibiotics, and barriers to prevention.

Antibiotic uses​

Wenonah Hauter, executive director of Food & Water Watch, said: “Right now, 80% of the antibiotics used in the US are used for industrial agriculture, and most of these drugs are routinely fed to animals to make them grow faster and compensate for filthy conditions. ​

“This is done to help the meat industry execute on its highly consolidated business model for profit. And the American public pays through antibiotic-resistant infections.”​

FDA is currently developing guidance for industry on the issue.

“Every time antibiotics are used in any setting, bacteria evolve by developing resistance. This process can happen with alarming speed,” ​said Steve Solomon, M.D., director of CDC’s Office of Antimicrobial Resistance.

“These drugs are a precious, limited resource—the more we use antibiotics today, the less likely we are to have effective antibiotics tomorrow.”​