Antibiotics Resistance: From Animals to People

Aug. 31, 2018
COLUMBUS, Ohio — It can be tough to stop using antibiotics on a farm.
Farmers need them to prevent and treat diseases in their animals. But increasingly, certain antibiotics used to treat illnesses in farm animals and humans are not working, said Greg Habing, an associate professor in the College of Veterinary Medicine at The Ohio State University.
More antibiotics are being used with humans and animals, and with each use, sensitive bacteria are killed and resistant bacteria grow and multiply. Those resistant bacteria can then trigger infections and become tougher for doctors and veterinarians to fight.
“The same resistant bacteria are affecting animals and people,” Habing said. “Human use of antibiotics has a bigger effect than agricultural use, but it’s still likely that agricultural use of antibiotics nonetheless has an important effect.”
In the past three years, fluoroquinolones—antibiotics that had long been used to fight human infections from salmonella as well as pneumonia in cows and pigs—have been shown to be ineffective against salmonella infections in a rising number of cases, Habing said.
Other antibiotics used to treat salmonella infections in humans are similarly losing their effectiveness. Beginning in the early 2000s, cephalosporins, which are used to fight infections in dairy cattle, started losing their ability to fend off salmonella infections in humans, Habing pointed out.
Habing will discuss “Antibiotic Use in Animals: Does It Matter for Human Health?” at the 56th annual Farm Science Review near London, Ohio, on Sept. 18 at 10:40 a.m. and Sept. 19 at 1:40 p.m. His talks are part of the “Ask the Expert” program in which individuals present their expertise on various agricultural topics, one of the many popular attractions at the Review, which is being sponsored by the College of Food, Agricultural, and Environmental Sciences (CFAES) at Ohio State.
When antibiotics are given to food animals, some of the bacteria those animals carry can become resistant to antibiotics, survive and spread. So if a consumer buys the animal’s meat and does not sufficiently cook the meat, the resistant bacteria may not have been killed off and instead get eaten. The resistant bacteria also can be eaten if the raw meat was cut with a knife that was later used to slice lettuce for a salad.
While preventive measures are important, Habing cautions that there’s no need for consumers to be alarmed. He notes that the threat of salmonella that’s resistant to antibiotics in the United States is low for healthy individuals with good food safety practices.
“A little bit of concern is warranted, but you can feel good about purchasing meat in the grocery store, especially if you’re handling and cooking the food appropriately.”
Since January 2017, farmers nationwide have no longer been allowed to use antibiotics to promote growth in their animals. They still can use them, however, to prevent and treat diseases.
Typically farmers are not quick to turn to antibiotics because that’s another expense, Habing said.
The solution to the growing problem of antibiotic resistance is not to eliminate the use of all antibiotics from farms, he pointed out.
“If a farmer has a calf with a bacterial infection and doesn’t treat it, that animal and others could suffer,” Habing said. “We want to make sure that animals that get bacterial infections get appropriately treated.”
The key for farmers is to try to prevent diseases in their animals as much as possible by being careful about introducing contaminants onto the farm through new animals or equipment. Adequate nutrition, clean housing conditions and appropriate vaccinations also can help keep animals from getting sick.
When animals do suffer illnesses, a veterinarian should help to accurately identify when antibiotics are needed and when they’re not, Habing said.
“What we’re trying to do is improve how farmers use antibiotics, but at the same time ensure animal welfare and farmer profitability,” he said.
Tickets for the Farm Science Review are $7 online, at county offices of CFAES’s Ohio State University Extension outreach arm and at participating agribusinesses, and are $10 at the gate. Children 5 and under are free. Show hours are 8 a.m. to 5 p.m. Sept 18-19 and 8 a.m. to 4 p.m. Sept. 20. For more information, visit
Alayna DeMartini
Greg Habing