11
Jul
As Millions Die from Antibiotic-Resistant Infections Annually, Study Shines Light on Pesticide Connection
(Beyond Pesticides, July 11, 2025) Pesticides and antibiotics are linked inextricably in the looming crisis of human and ecosystem health. Both started out as quasi-miraculous solutions to age-old human problems, yet it has been clear that the failures of each present severe challenges—and that they are synergistic because they trigger the same kinds of defensive mechanisms in their targets: insects, fungi and weeds on the one hand, and microbes on the other. A review of contamination of waterways in India with pesticides and antibiotics, published in Environmental and Geochemical Health, recounts the many threats that arise when these chemicals mix, and how their presence in water makes the problems much worse.
Globally, about five million people died in 2019 from infections with antibiotic-resistant microbes. By 2050, according to a World Bank estimate, antibiotic resistance could add $1 trillion to global health care costs and subtract $3.4 trillion from annual global gross domestic product. While the world slowly realizes the urgent need to counter antibiotic resistance, the role of pesticides in generating it has received less political and public attention. But there is no doubt that pesticides are strongly implicated. In fact, the resistance of microbes to antibiotics is no different from the well-documented resistance of insects and plants to pesticides.
The presence of both pesticides and antibiotics in water bodies—lakes, rivers and oceans—and especially those receiving both agricultural runoff and hospital waste—multiplies the risk of antimicrobial resistance. Further, the waters of the world are largely connected, from snow zones to oceans, so that in many cases what enters one body of water affects everything downstream.
India’s experience with pesticides began with the Green Revolution, which spread globally from the mid-1940s to the mid-1980s. DDT and benzene hexachloride (BHC) were introduced in 1948 in India. The first BHC factory was built in 1952, and India subsequently became a major manufacturer of pesticides. It was not until 1971 that a national pesticide regulation was established. The country’s pesticide evolution has since undergone phase transitions similar to those in the United States and Europe—from DDT to organochlorines, organophosphates, carbamates, pyrethroids and more recently neonicotinoids. From the 2000s onward, Indian pesticide production has burgeoned and the country is currently the fourth-largest producer of agrochemicals.
Antibiotic resistance is a classic case of natural selection: Not every organism will be killed by a toxicant, and the survivors reproduce to create a population of resistant individuals. This has been a recognized problem for at least two centuries, but microbial resistance is accelerating as the world becomes more and more saturated with chemicals that trigger natural selection. Pesticides have profound effects on microbes, including in the human gut, and often function as antibiotics whether intentionally or not.
Microbes have numerous ways of evading pesticides’ antibiotic properties—efflux pumps, horizontal gene transfer, biofilm formation—and bacteria possessing all these skills are especially good at multi-drug resistance. Efflux pumps allow bacteria to eject foreign and toxic material from their cells.
Horizontal gene transfer and genetic mutations allow bacteria to alter cellular defenses, often through the transmission of plasmids, which are packets of resistance genes and their helper DNA elements. These genes can change membrane permeability, dismantle antibiotics, or change the target of an antibiotic or pesticide. Biofilms protect a wide variety of microorganisms from antibiotics, cleaning agents, and even abrasion. According to the Indian review, biofilms occur frequently in agricultural runoff, sewage systems, and their receiving waters. Bacteria living inside a biofilm can be a thousand times more resistant to antibiotics than those living freely, the authors write, and biofilms often harbor persister cells, which remain dormant when exposed to antibiotics and afterwards revive to regenerate the biofilm. They also make horizontal gene transfer more likely.
These defense mechanisms increase as the selective pressure, whether from pesticides or antibiotics, increases, and in areas where both pesticides and antibiotics are present, the rate at which resistance evolves speeds up. Specific pesticides have been associated with resistance to specific antibiotics. According to the Indian review, glyphosate, 2,4-D and dicamba help bacteria develop resistance to tetracycline and ampicillin. (See Glyphosate Induces Antibiotic Resistance in Deadly Hospital-Acquired Infection.) Chlorpyrifos increases multidrug-resistant plasmid transfers. The fungicide azoxystrobin causes Pseudomonas aeruginosa to bolster its efflux pump capacity. (See Daily News.) and Pesticides and You.)
The Indian review analyzes the evidence of antibiotic resistance and pesticides in Indian aquatic ecosystems. According to the authors, numerous aquatic environments in India show signs of being antibiotic resistance nurseries, from the Ganges and Yamuna rivers in the north to the Thamirabarani in the southern Tamil Nadu state. These areas receive heavy amounts of agricultural runoff. Seawater along the coasts harbors Vibrio bacteria – pathogens of cholera and gastroenteritis – that are antibiotic-resistant. India is also a leader in pharmaceutical manufacturing, which contributes significant effluent to surface waters; wastewater treatment facilities receiving such effluent are known antibiotic resistance hotspots. Groundwater in India is likewise polluted; researchers have also found resistant E. coli strains in Assam and Uttar Pradesh in groundwater contaminated with agricultural products.
Aquaculture is emerging as a serious incubator of pesticide-antibiotic induced resistance. A study of finfish aquaculture in Bangladesh found extensive use of many antibiotics and pesticides.
India uses relatively few pesticides, with an application rate of 0.4 kg per hectare, compared to China, which uses 1.83 kg per hectare. It actually manufactures and exports more than it uses internally, according to the review. But between the manufacture of pharmaceuticals and pesticide and their use internally, much of the country is contaminated. India has gradually increased pesticide regulation, banning the organochlorine compound endosulfan in 2011, which reduced the scourge of pesticide-related suicides significantly. It passed the Prevention of Food Adulteration Act in 2014, and there have been some attempts to incorporate alternative pest management practices, but these are inconsistent and spotty.
Ultimately there is no avoiding the end-state of pesticide use, which is an increasingly toxic environment populated by those organisms that can survive it, which are uncontrollable by current methods.
As the review authors put it, “The time for half-measures and bureaucratic reluctance is passed; India needs to take immediately action to defend its water resources and public health from this unpredictable yet growing problem.”
As Beyond Pesticides wrote in a Commentary last year, “[W]e must stop broadcasting pesticides in the environment. The crisis in antibiotic resistance, which creates a threat of another pandemic, is ignored in the registration of pesticides. The antibiotic impacts of pesticides…were discovered only after the pesticides had been disseminated in the environment for decades. EPA must not register pesticides unless they have been demonstrated not to contribute to antibiotic resistance and must cancel the registration of those that do.” (See Agricultural Uses of Antibiotics Escalate Bacterial Resistance.)
Beyond Pesticides’ position is that the twin problems of pesticides’ multifarious toxicities and antibiotics’ inevitable uselessness are not categorically distinct, but rather two aspects of the same mistaken assumption – that we can dominate nature by brute force. They can be reversed by switching to organic and regenerative agriculture. Resistance to both pesticides and antibiotics is inevitable, and thinking otherwise is magical thinking.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
Pesticide‑driven antimicrobial resistance in water bodies: insights on environmental concerns, health implications and mitigation strategies
Sonkar et al
Environmental and Geochemical Health 2025
https://link.springer.com/article/10.1007/s10653-025-02600-y
Local applications but global implications: Can pesticides drive microorganisms to develop antimicrobial resistance?
Ramakrishnan et al
Science of the Total Environment 2018
https://www.academia.edu/85694036/Local_applications_but_global_implications_Can_pesticides_drive_microorganisms_to_develop_antimicrobial_resistance
Commentary: We Can and Must Stop Antibiotic Pesticide Use in the Interest of Public Health Worldwide
Beyond Pesticides, January 8, 2024
https://beyondpesticides.org/dailynewsblog/2024/01/commentary-we-can-and-must-stop-antibiotic-pesticide-use/
Amounts of Pesticides Reaching Target Pests: Environmental Impacts and Ethics
David Pimentel
Journal of Agricultural and Environmental Ethics 1995
https://r.jordan.im/download/environmentalism/pimentel1995.pdf
Mechanism for Escalating Antibiotic Resistance in Agriculture Detailed in Study, as Crisis Grows
Beyond Pesticides, January 2, 2025
https://beyondpesticides.org/dailynewsblog/2025/01/mechanism-for-escalating-antibiotic-resistance-in-agriculture-detailed-in-study-as-crisis-grows/
Study Finds Synergistic Convergence of Global Warming, Pesticide Toxicity, and Antibiotic Resistance
Beyond Pesticides, May 1, 2025
https://beyondpesticides.org/dailynewsblog/2025/05/study-finds-synergistic-convergence-of-global-warming-pesticide-toxicity-and-antibiotic-resistance/
