20 Apr 2026
A team of Italian scientists says a “one health” approach is needed after their analysis suggested wildlife could act as a “reservoir” of resistance.
Chris Simpson
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Image: Lutz / Adobe Stock
Wildlife surveillance could serve as an “early warning system” for signs of spreading antimicrobial resistance (AMR), according to a newly published study.
The claim is based on samples from red foxes and several bird species in northern Italy, which indicated resistance levels several times higher than those seen in human patients.
Scientists at the University of Parma say they have isolated a “high-risk” clone of a bacterial and enzyme variant that can render antibiotics ineffective. They also claimed their findings suggested wildlife could be a clinically significant “reservoir” of resistance and argued a range of measures were needed to help address the issue.
Co-author Mauro Conter said: “What we see is a complex problem that requires ‘one health’ solutions addressing antibiotic pollution, climate-driven wildlife behavioural changes and bacterial population dynamics.
“Our data justify routine wildlife AMR monitoring as a public health early warning system, guiding environmental interventions before resistance reaches clinical settings.”
The study, published in Frontiers in Microbiology, examined nearly 200 fecal samples from red foxes, which are thought to contribute to the short-range spread of AMR, plus more than 300 from crows, magpies and water birds which can add to the issue over much longer distances.
The report found Klebsiella species bacteria, which can produce enzymes capable of neutralising antibiotics, were present in 32 samples. But while it was only seen in 2% of the samples, the paper suggested the presence of Klebsiella pneumoniae in several species demonstrated the potential for AMR to circulate in the environment.
The authors stressed the study had not been designed to highlight potential points of direct transmission between wildlife and humans. But they argued a range of measures were still necessary to help tackle the problem, including reducing antibiotic pollution of wastewater, improving sewage treatment, encouraging more prudent antimicrobial usage in livestock and restricting specific “critically important” products solely to human use.
Dr Conter, an associate professor in the University of Parma’s veterinary science department, said: “Even a 2% prevalence in wildlife represents environmental contamination by high-risk clones.
“K pneumoniae readily spills over through water and waste routes, creating a continuous human-animal-environment resistance cycle.”
The study also found all the K pneumoniae isolates were resistant to both third-generation cephalosporins, which are used to treat conditions including meningitis and sepsis, and fluoroquinolones which can be deployed for pneumonia and urinary tract infections.
That compared to equivalent levels of 19.6% and 17.4%, respectively, among human patients in Italy, or 9.3% and 8.8% across the EU.
The paper said: “From a one health perspective, the detection of such clinically relevant strains in wildlife highlights the need for integrated surveillance systems that recognise wildlife as a strategic component of broader antimicrobial resistance monitoring and prevention strategies.”