The Environment: The Missing Link in the Fight Against Antimicrobial Resistance

The inappropriate use of antibiotics has led to the emergence of bacteria resistant to these drugs, which are designed to fight infectious diseases such as urinary tract infections but are ineffective against viral infections such as influenza.

This misuse of antibiotics has triggered a global emergency that affects not only human health but also the entire ecosystem. On the occasion of World Environment Day, we want to underscore the importance of this issue by calling for action to mitigate the harmful effects of antimicrobial resistance.

The misuse of antibiotics has triggered a global emergency that affects not only human health but also the entire ecosystem

“One Health”—the notion that human and animal health are interdependent and linked to the ecosystems where they coexist—has gained prominence in recent years. It is important to understand the concept of antimicrobial resistance from a One Health perspective. Every day, vast amounts of biocides—products widely used for disinfection and cleaning—are released into the environment by livestock, aquaculture, agriculture, hospitals and pharmaceutical companies. The environmental pollution generated by biocide release contributes significantly to the spread of antibiotic resistance.

The European Medicines Agency has noted that, on a per-animal basis, Spain is one of Europe’s leading users of antibiotics in food-producing animals. Antibiotics are administered not only to promote animal growth, but also to prevent infection in healthy animals that do not need them. Although intensive livestock farms should be required to respect the established time intervals between the administration of an antibiotic and the animal’s entry into production or the collection of their products (milk or eggs), these regulations are often inadequately enforced.

“One Health”—the notion that human and animal health are interdependent and linked to the ecosystems where they coexist—has gained prominence in recent years

Given these issues, it is essential to implement good production practices, improve hygiene measures and promote animal welfare to prevent the unnecessary use of antibiotics. Spain has introduced a National Antibiotic Resistance Plan (PRAN), which seeks to incentivise programmes to monitor antibiotic resistance indicators as well as programmes to voluntarily scale back the use of certain antibiotics in particular species, which, from a veterinary perspective, would go a long way towards improving the situation. PRAN also seeks to promote the rational use of antibiotics by strictly monitoring those classified as critical—for example, colistin, an antibiotic that is widely used on farms but is also considered a last-resort treatment for multidrug-resistant bacteria in hospital settings.

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But intensive animal farming is not the only area of concern. Certain antibiotics are commonly used in fruit and vegetable crops to control bacterial plant pathogens. In 2018, a study by Kurenbach et al. found that bacteria developed antimicrobial resistance at a rate up to 100,000 times faster when concurrently exposed to certain herbicides commonly used in agriculture.

The European Medicines Agency has noted that, on a per-animal basis, Spain is one of Europe’s leading users of antibiotics in food-producing animals

Although the amount of antibiotics used in agriculture is considerably lower than that used in the medical and veterinary fields, in some countries regulatory surveillance and monitoring of antimicrobial use in agricultural settings is weak or inadequate, according to a report by the Food and Agriculture Organisation (FAO) of the United Nations.

In this context, the monitoring of antibiotic use in agricultural production should be optimised and treated as a health-, medical- and food-related priority.

But intensive animal farming is not the only area of concern. Certain antibiotics are commonly used in fruit and vegetable crops to control bacterial plant pathogens

Finally, water plays a key role in the spread of antimicrobial resistance genes, as some crops are irrigated with contaminated water or water containing antibiotic residues.

We must therefore embrace the initiative of the national and international organisations that have called for worldwide cooperation on the rational use of antibiotics, not only for human and animal health, but also for plant and environmental health, in order to counteract antimicrobial resistance under the umbrella of One Health.