3 animal antibiotics, human health risk questions answered
Clear link between antibiotic resistance emerging on farms and drug-resistant infections in people.
Read the entire report about antibiotics and human health risks exclusively in the March issue of Poultry International.
The U.S. nonprofit organization has produced an issue brief looking at the role of antibiotics used on farms in the emergence of antibiotic resistance and how resistant bacteria spread to people.
It notes that while the path from antibiotic use in animal agriculture to the subsequent public health risk posed by resistant bacteria is a complex one, the connection is irrefutable.
The briefing document offers a high-level overview of scientific data available to address three key questions:
- Does antibiotic use on farms and feedlots lead to resistant bacteria emerging?
- Are resistant bacteria on farms or feedlots infecting people?
- Are infections with resistant bacteria worse than if the bacteria were not resistant?
Pew notes that the molecular processes by which resistance emerges, spreads and potentially disappears are complex.
Some resistant genes occur naturally, fully independent of exposure to antibiotics.
Additionally, not every antibiotic works against every type of bacterium. For instance, an antibiotic may be effective only in killing bacteria with a certain type of molecular structure, leaving those without that structure unaffected.
Bacteria can acquire antibiotic resistance through various mechanisms. It may be acquired sequentially, and how quickly this occurs depends on several factors, including the bacterium type, the negative effect any changes have, and the nature of antibiotic exposure.
However, bacteria can also quickly develop resistance when they share their resistance genes. Bacteria can also share several genes at the same time, including those that confer traits unrelated to resistance, which can complicate resistance dynamics through a process called co-selection.