Resistance to antibiotics and pesticides is rising at alarming rates. Yet, currently there is no global framework to track the threat to human health and crops.
Researchers have now published the first estimates of antibiotic and pesticide "planetary boundaries" in the journal Nature Sustainability. The researchers suggest that if resistance to antibiotics and pesticides goes beyond these boundaries, societies risk large-scale health and agricultural crises.
The new research concludes that Gram-negative bacteria, a group of bacteria that includes well-known pathogens such as Salmonella, Klebsiella pneumoniae, and E. coli, are already beyond the "planetary boundary", as some strains of several species are already resistant to all or most antibiotics tested.
"It appears as if we have crossed a tipping point for Gram-negative bacteria, with doctors increasingly reporting untreatable infections. We now need to manage these 'nightmare bacteria' differently," says lead author Peter Søgaard Jørgensen from the Global Economic Dynamics and the Biosphere programme at the Royal Swedish Academy of Sciences and Stockholm Resilience Centre, Stockholm University.
"Without new approaches, going to hospital in the future will increasingly become a gamble. More patients will get unlucky, and become infected with untreatable or hard to treat bacteria. This is an urgent risk to human society," says Søgaard Jørgensen.
The team defined and assessed the state of the planetary boundary for six types of resistance including: antibiotic resistance in Gram-negative and Gram-positive bacteria; general resistance to insecticides and herbicides and resistance to transgenic Bt-crops and glyphosate resistance in herbicide resistant cropping systems. All six assessed boundaries are in zones of increasing risk and three out of six are in zones of high regional or global risk.
Pesticide resistance is an urgent concern, particularly resistance to glyphosate (the core ingredient in the herbicide Roundup) and insecticidal Bt-toxins in transgenic crops, which are now widespread.
The researchers' assessment suggests that some herbicides and Bt toxins have already reached regional boundaries with some farming areas reporting large-scale resistance to these pesticides.
"A benefit of crops resistant to glyphosate is that they help farmers control weeds already resistant to other herbicides," says Yves Carrière, an author on the study from the University of Arizona. "But rapid and widespread evolution of resistance to glyphosate in many weeds has sometimes left few effective herbicides for the control of weeds with multiple resistance."
"Without better weed management programs it is just a matter of time before this herbicide planetary boundary is also transgressed," adds Carrière.
The historical evidence suggests that reversing the spread of resistance is unlikely explains Søgaard Jørgensen. "Once resistance becomes established, it is unlikely to completely disappear again." In addition, increasing efforts to fully eradicate bacteria and pests is likely to make matters worse. Instead, new strategies are needed that promote the growth of bacteria and pests that are susceptible to pesticides and antibiotics, at the expense of those with resistance.
"Susceptible insects, plants and bacteria provide a benefit to society, promoting them can be part of a new and broader strategy of chemical de-escalation for the 21st century," says Søgaard Jørgensen. These new strategies need to promote the importance of sustaining susceptibility to pesticides and antibiotics and account for the many other services that microbes, plants and insects provide to us through e.g. pollination, biological control, and benefits to human health.
"These strategies are urgently needed as complements to development of new antibiotics and pesticides. Together they have the potential to bring us back inside the boundaries to a zone of lower risk", says Søgaard Jørgensen.
Notes to editors
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Paper title, DOI, publication date
Antibiotic and pesticide susceptibility and the Anthropocene operating space
Nature Sustainability, https:/
Research institutes involved
Authors from the Living with resistance project involved in this study come from the following institutions:
- Global Economic Dynamics and the Biosphere Royal Swedish Academy of Sciences Stockholm Sweden
- Stockholm Resilience Centre Stockholm University Stockholm Sweden
- Department of Psychology Arizona State University Tempe AZ USA
- North Carolina State University Raleigh NC USA
- University of Arizona Tucson AZ USA
- CSIRO Agriculture and Food Narrabri NSWAustralia
- University of Waterloo Waterloo Ontario Canada
- SESYNC, University of Maryland Annapolis MD USA
- Department of Population Medicine and Diagnostics Science Cornell University Ithaca NY USA
- South Asia Biotechnology Centre New Delhi DelhiIndia
- ReAct - Action on Antibiotic Resistance, Department of Medical Sciences Uppsala University Uppsala Sweden
- Department of Emergency Medicine Johns Hopkins School of Medicine Baltimore Maryland USA
- Michigan State University East Lansing MI USA
- Universidade de São Paulo São Paulo Brazil
- Department of Veterinary Pathobiology Texas A&M University College Station TX USA
- Geneva Transformative Governance Lab, Global Studies Institute University of Geneva Geneva Switzerland
- School of Public Health, Li Ka Shing Faculty of Medicine The University of Hong Kong Hong Kong Special Administrative Region People's Republic of China
- Department of Entomology and Nematology University of California at Davis Davis CA USA
What the study did:
The team defined and assessed the state of the planetary boundary for six types of resistance, including antibiotic resistance in Gram-negative and Gram-positive bacteria; general resistance to insecticides and herbicides and resistance to transgenic Bt-crops and glyphosate resistance in herbicide resistant cropping systems.
All six assessed boundaries are in zones of increasing risk and three out of six are in zones of high regional or global risk.
Antibiotic resistance is involved in hundreds of thousands of deaths each year, especially in newborns and immunocompromised people.
Complete resistance to all available antibiotics is documented in an increasing set of Gram-negative bacteria, such as Acinetobacter, Pseudomonas aeruginosa, and species of the Enterobacteriaceae family, such as Klebsiella pneumonia.
For example, over 60 % of 1300 infectious disease specialists surveyed primarily in North America reported encountering these types of pan-resistant infections.
For pesticide resistance, a particular concern is resistance related to transgenic crops that depend on the effectiveness of a few insecticides or herbicides.
Transgenic crops have become increasingly widespread with insecticidal Bt-crops making up more than 15 % of the area for crops in which they are available.
Herbicide resistant crops resistant to glyphosate are grown on about 30% of the area of the crops for which they are available and glyphosate accounts for 60% of all herbicides used by volume.
In some regions, such as India and the United States Midwest, insects are resistant to all regionally available toxins.
Glyphosate resistance is spreading to an increasing number of species in all regions.
New strategies needed:
The researchers highlight the need for strategies to combat the problem of resistance that help reduce the use of antibiotics and pesticides. This is because extensive pesticide and antibiotic use can undermine benefits human receive from nature (ecosystem services).
For example, pesticides can be harmful to insect pollinators pollinating 75% of cultivated crops and antibiotics can compromise the increase human vulnerability of to co-infections.
The best documented example of such co-infections is the rising epidemic of Clostridium difficile, an opportunistic bacterial pathogen that in the United States every year infects around 450,000 people and kills 30,000.