Manure management could be the key in decreasing the development of bacteria that are resistant to antibiotics.
A team of researchers at Iowa State University were recently awarded a $1 million grant from USDA’s National Institute of Food and Agriculture to study how technologies can decrease development of those bacteria.
Adina Howe, an ag engineer with ISU and principal investigator on the grant, says this grant will allow researchers to build on work showing how livestock production interacts with complex factors, such as environmental processes, to contribute to antibiotic resistance.
“As antibiotic resistance has become more of a global threat, more research funding is becoming available,” she says.
She says roughly 70% of all antibiotic usage involves livestock.
Antibiotic resistance is the process by which disease-causing bacteria develop the ability to protect themselves against medications used to stop them. Antibiotic resistance poses a growing threat to human, animal and environmental health because the speed of resistance currently outstrips the speed with which new antibiotics are being developed, Howe says.
This trend could limit the availability of treatments for a range of maladies and infections, both in humans and animals.
“The reason this is so important is we cannot discover new antibiotics fast enough to fill in for the medications that are losing their effectiveness,” she says.
The focus of the research will be manure management, Howe says.
“Can we stop this by treating manure before it gets to the field?” she says.
Researchers will focus on hog manure for this study. Samples will be collected from farms throughout Iowa. Some samples will come from pigs that have been exposed to antibiotics, while other samples will come from pigs that have not been treated with antibiotics.
The researchers’ work will fill gaps in science’s understanding of how livestock production, particularly manure management, can reduce the spread of antibiotic-resistant bacteria, Howe says. Antibiotic-resistant bacteria can wind up in manure before making their way into the environment, such as when manure is applied to fields as fertilizer.
The researchers aim to figure out what resistant genes are proliferating in bacteria and how widely those bacteria spread and persist in soil. They will connect the antibiotic-resistant bacteria in the manure with the specific antibiotics applied to pigs involved in the experiments.
The researchers also will examine the feasibility of various methods to stop the spread of resistant bacteria, such as decomposition with composting. They’ll also look at anaerobic digestion, in which manure is sealed in an oxygen-free tank and broken down into biogas and bio-fertilizer.
Howe says human, animal and environmental health interact in complex ways that influence the pace at which antibiotic resistance spreads, a concept known as “One Health.” She says her research helps to shed light on how these factors connect.
“We’re all connected far more closely that we previously recognized — humans, the environment and agriculture,” Howe says.
The research team also includes ISU ag engineers Michelle Soupir and Dan Andersen, and Diana Aga, professor of chemistry at the University at Buffalo.