According to an analysis published in the journal Science, antibiotic resistance among bacteria affecting food animals has nearly tripled over the past 20 years.
The team of researchers from ETH Zurich, the Princeton Environmental Institute (PEI), and the Free University of Brussels collected information from nearly 1,000 publications and unpublished veterinary reports for their analysis, including a map of antimicrobial resistance in low- to middle-income countries.
For this analysis, the researchers focused on animal pathogens that can also cause disease in humans, such as Escherichia coli, Campylobacter, Salmonella, and Staphylococcus aureus.
According to the researchers, transition to high-protein diets in low- and middle-income countries (LMICs) has helped drive expansion of intensive animal production systems incorporating antibiotic use. Globally, 73% of all antimicrobials sold on Earth are used in animals raised for food, according to the report, and in many LMICs, farmers have easy over-the-counter access to medically important antibiotics.
The researchers note that between 2000 and 2018, the proportion of antibiotics showing rates of resistance above 50% in developing countries increased in chickens from 0.15 to 0.41 and in pigs from 0.13 to 0.34. This means that antibiotics that could be used for treatment failed more than half the time in 40 percent of chickens and one-third of pigs raised for human consumption.
They conclude that, in regions where resistance is emerging, there is a window of opportunity to limit the rise of resistance by encouraging a transition to sustainable animal farming practices. High-income countries, where antimicrobials have been used on farms since the 1950s, should support this transition—for example, through a global fund to subsidize improvement in farm-level biosafety and biosecurity.
For more on global antibiotic resistance, see these articles from BovineVetOnline: