J. Microbiol. Infect. Dis., (2026), Vol. 16(2): 126–136

Review Article

10.5455/JMID.2026.v16.i2.9

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Antibiotic use across human, animal, and environmental systems drives global antimicrobial resistance: A One Health perspective

Fernando de Sá Del Fiol

Doctoral Program in Pharmaceutical Sciences, University of Sorocaba, Sorocaba, SP, Brazil

*Corresponding Author: Fernando de Sá Del Fiol. Doctoral Program in Pharmaceutical Sciences, University of Sorocaba, Sorocaba, SP, Brazil. Email: fernando.fiol [at] prof.uniso.br

Submitted: 30/03/2026 Revised: 25/05/2026 Accepted: 03/06/2026 Published: 21/06/2026

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ABSTRACT

Antimicrobial resistance (AMR) is one of the most critical global health challenges and is strongly associated with excessive and inappropriate antibiotic use across human, animal, and environmental systems. The interconnected nature of these sectors highlights the importance of integrated approaches to understanding and mitigating the dissemination of resistant microorganisms. The aim of this review was to critically analyze the relationship between antibiotic use and AMR within human, animal, and environmental ecosystems using a One Health framework. This narrative review synthesized evidence from PubMed/MEDLINE, Scopus, and Web of Science studies published between 2000 and 2024. The literature search focused on antimicrobial use in human medicine, livestock production, aquaculture, pharmaceutical industry effluents, and wastewater contamination. Studies were qualitatively analyzed to identify patterns, regional differences, environmental dissemination pathways, and public health implications associated with AMR. Excessive antibiotic use in humans, livestock, and aquaculture significantly contributes to the emergence and spread of AMR. Environmental contamination through pharmaceutical effluents and wastewater treatment systems further promotes resistance gene persistence and dissemination. Considerable regional disparities were identified, particularly between high-income countries with stricter antimicrobial regulations and low- and middle-income countries with limited regulatory and infrastructure. Evidence consistently show a strong association between antibiotic consumption and resistance indices across multiple ecosystems. AMR is a multifactorial and interconnected global problem requiring coordinated interventions across human, animal, and environmental sectors. Integrated surveillance systems, antimicrobial stewardship programs, stricter environmental regulations, and sustainable alternatives to antibiotics are essential for mitigating the spread of resistance. The One Health framework remains fundamental in guiding global strategies aimed at preserving the effectiveness of antimicrobials and protecting public health.

Keywords: Antimicrobial resistance, One Health, Environmental pollution, Aquaculture.

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Introduction

The One Health concept emerged as an integrated framework to address global challenges at the intersection of human, animal, and environmental health. It recognizes the deep interconnection between these three domains, in which actions in one area can have direct and indirect impacts on the others (Mackenzie and Jeggo, 2019).

The term “One Health” gained popularity through international organizations such as the World Health Organization (WHO), the World Organization for Animal Health (WOAH), and the Food and Agriculture Organization (FAO) of the United Nations. These organizations have emphasized the need for a multisectoral perspective to address global challenges (Karesh et al., 2012).

While the central idea of One Health is not new, it gained significant recognition in the early 21^st century, particularly with the growing awareness that many emerging infectious diseases are zoonotic, transmissible between animals and humans. For example, close interactions with wild and domestic animals facilitate pathogen transmission between species, as observed in zoonotic diseases, where infections are passed from animals to humans. Emerging zoonotic diseases such as SARS, Ebola, and COVID-19 reinforced the importance of the One Health concept by demonstrating how interactions between humans, animals, and ecosystems can facilitate the emergence and global spread of infectious diseases. Beyond zoonoses, these interactions also influence the dissemination of antimicrobial resistance (AMR) through antibiotic use, environmental contamination, and microbial exchange across ecosystems. Thus, the relationship between environmental degradation and human health is a critical factor in the emergence of new diseases (Jones et al., 2008). Table 1 shows the major epidemics that have affected humanity, along with their animal reservoirs and etiological agents.

Table 1 summarizes the history of major zoonotic epidemics, their animal reservoirs, and their global impact.

Human exposure to the forest and animal microbiome raises significant concerns, particularly in the context of public health and environmental conservation. Microorganisms present in natural environments, while essential for ecological balance, can pose risks to human health, as evidenced by the emergence of zoonotic diseases (Woolhouse and Gowtage-Sequiera, 2005; Jones et al., 2008).

The reverse is also true and much more concerning, as human interference, whether direct or indirect, with the microbiome of the environment they inhabit brings numerous consequences. This interference occurs in various ways, affecting the composition, diversity, and functionality of the microorganisms that inhabit different ecosystems. The extensive use of antibiotics in human and veterinary medicine, as well as their improper disposal, are critical factors that alter the environmental microbiome. Antibiotics used to treat human infections and promote animal growth are often excreted into the environment, contaminating soil and water, thereby promoting AMR and altering local microbial compositions (Mulchandani et al., 2023).

Table 1. Key epidemics in history: animal sources and global impact.

Despite the growing body of literature addressing AMR, integrative analyses that comprehensively connect human, animal, and environmental dimensions within a unified One Health framework are lacking. This study aims to fill this gap by providing a critical and integrated analysis of the main drivers of AMR across these interconnected domains, highlighting their implications for global health and public policy.

Unlike previous reviews that primarily focus on isolated sectors, such as human medicine or livestock production, this review integrates evidence from human, animal, environmental, and industrial sources within a unified One Health framework. In addition to summarizing current evidence, this study critically discusses regulatory disparities, environmental contamination pathways, and global inequalities associated with AMR.

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Methodology

This study consists of a narrative literature review to analyze the relationship between antibiotic use and AMR from a cross-sectoral perspective. The review was conducted using scientific articles indexed in PubMed/MEDLINE, Scopus, and Web of Science.

The search strategy included combinations of the following descriptors: “AMR,” “antibiotic use,” “One Health,” “environmental contamination,” “livestock,” “aquaculture,” and “wastewater.” We considered articles published in English between 2000 and 2024.

The literature search was conducted between January and March 2025. The review did not aim to perform a systematic quantitative synthesis but rather to critically integrate evidence from multiple sectors involved in AMR under the One Health perspective. The selected studies were interpreted qualitatively, emphasizing recurring findings, regional differences, regulatory challenges, and gaps in current evidence.

Studies were selected according to predefined relevance criteria, including: (1) direct association with AMR within human, animal, or environmental systems; (2) publication in peer-reviewed journals or official reports from international organizations; and (3) presentation of quantitative or conceptual data relevant to the One Health framework. Preference was given to large epidemiological studies, systematic reviews, multicenter investigations, and reports from organizations such as the WHO, FAO, WOAH, and the European Center for Disease Prevention and Control.

Studies with limited relevance to AMR, duplicate information, or lacking sufficient methodological description were excluded from the narrative synthesis. The analysis focused on identifying patterns, trends, and interactions between human, animal, and environmental antibiotic use and their impact on AMR.

The selected literature was critically interpreted to provide an integrated and interdisciplinary understanding of the topic, emphasizing knowledge gaps and implications for public health policies.

Use of antibiotics in livestock

Excessive and improper use of antimicrobials in humans and animals has accelerated the emergence of resistant strains. These drugs are widely used in animal production to treat and prevent infectious diseases and are often used as growth promoters. The non-therapeutic use of antimicrobials, as seen in intensive livestock farming, directly contributes to the selection of resistant microorganisms that can spread to humans through the food chain or the environment. (Mohamed et al., 2024).

In recent decades, the use of antibiotics in livestock has grown alarmingly, reflecting the global expansion of the agricultural sector, which seeks to meet the increasing demand for animal protein. In 2013, global antibiotic consumption in livestock production was estimated at approximately 131,109 tons, with projections reaching 200,235 tons by 2030 (Mulchandani et al., 2023). These numbers highlight the enormous environmental burden associated with global antimicrobial consumption in livestock production. This projected increase reflects common practices in countries such as China, the world’s largest consumer of veterinary antimicrobials, where up to 318 mg of antibiotics are used per kilogram of animal product. In comparison, countries such as Norway have significantly lower animal product consumption, with only 8 mg per kilogram. These figures emphasize the vast disparity in the use of antimicrobials between countries and highlight the pressing need for stricter regulations to control this practice (Mulchandani et al., 2023).

According to a study conducted by Van Boeckel et al. (2015), the average global annual consumption of antimicrobials per kilogram of animal produced varies significantly between species. Cattle consumption is approximately 45 mg per kilogram of body weight produced. In comparison, the consumption of chickens is significantly higher, reaching around 148 mg per kilogram, whereas that in pigs is even greater, estimated at 172 mg per kilogram. These variations reflect the different management practices and health needs of animals in intensive production systems, where antimicrobials are commonly used to prevent diseases and promote growth (Van Boeckel et al., 2015).

The consequences of excessive antibiotic use in livestock are widespread and alarming. Up to 80% of the antibiotics administered to animals are excreted, entering the environment through animal waste and untreated effluents (Tamhankar and Stålsby Lundborg, 2019). The presence of antibiotic residues in various environmental compartments, including soil, water, and plants, creates a favorable environment for the development and spread of resistant bacteria. In areas with intensive farming practices, such as certain regions of China and India, the concentration of antibiotic residues and resistance genes in water and soil can be alarmingly high, thereby exacerbating the problem of AMR (Tamhankar and Stålsby Lundborg, 2019).

Given the severity of the situation, several approaches have been proposed to mitigate the use of antibiotics in livestock and contain the spread of AMR. The imposition of a global limit of 50 mg of antibiotics per kilogram of animal product per year could reduce total consumption by up to 64%. Other strategies include reducing global meat consumption to recommended levels, such as 40–70 g per day, which could decrease the demand for antibiotics by up to 66% (Van Boeckel et al., 2017; Malik et al., 2023; Cusack, 2024). In addition, the introduction of a usage fee for veterinary antimicrobials could reduce consumption by up to 31%, generating revenue that could be reinvested in the discovery of new antimicrobials and the improvement of farming practices. If implemented effectively, these measures could offer a viable solution to reduce the impact of antibiotics in livestock farming and protect global public health (Malik et al., 2023; Cusack, 2024).

However, antimicrobial consumption patterns vary considerably between countries due to differences in regulatory frameworks, economic conditions, and livestock production models. While high-income countries have progressively restricted the use of growth-promoting antibiotics, many low- and middle-income countries still face challenges related to veterinary oversight, food security demands, and limited regulatory enforcement.

Antibiotics in pharmaceutical industry effluents

Pharmaceutical industry effluents are one of the most concerning sources of environmental contamination by antibiotics due to the high concentrations of active compounds that can be released directly into the environment without adequate treatment. Studies conducted worldwide, particularly in countries with weak environmental regulations such as India and China, have shown alarmingly high antibiotic levels in rivers and lakes near pharmaceutical industries. A notable study conducted in Hyderabad, India, detected 31 mg/l of ciprofloxacin in the effluent from a pharmaceutical industry, a concentration that was thousands of times higher than the therapeutic levels in humans (Larsson et al., 2007). The maximum allowed concentration of antibiotics in water bodies should be in the range of ng/l to μg/l to avoid ecological impacts (Rizzo et al., 2013).

Pharmaceutical effluents contain a variety of antibiotics, including fluoroquinolones (such as ciprofloxacin), macrolides, tetracyclines, and sulfonamides, as well as residues of other pharmaceutical products. These substances are released at varying concentrations depending on the plant’s production capacity and waste-treatment efficiency. More than 45 different substances have been detected in the effluents of these industries in some regions (Kraemer et al., 2019).

High concentrations of antibiotics in effluents create an environment conducive to the selection and spread of resistance genes. Bacteria exposed to these levels can develop resistance mechanisms that can eventually be transferred to human and animal pathogens. A study in China demonstrated that the concentration of resistance genes in environmental bacteria was up to 100 times higher in areas near pharmaceutical industries than in areas not impacted by these factories (Zhang et al., 2015).

Prolonged exposure of aquatic organisms, such as algae, fish, and invertebrates, to antibiotics can lead to sublethal and chronic effects, including changes in the behavior, growth, and reproduction of these species. Fish exposed to antibiotics, for example, have reduced reproduction and growth rates, as well as altered intestinal microbial communities (Pan et al., 2023).

Regulations regarding the disposal of pharmaceutical effluents are insufficient or poorly enforced in many countries. The European Medicines Agency and the U.S. Environmental Protection Agency have guidelines for controlling antibiotic waste; however, the implementation of these standards varies widely between countries. In India, for example, new regulations have only recently been proposed to limit industrial waste discharges, but there are still challenges in monitoring and ensuring compliance from industries (Fick et al., 2009).

Despite the alarming levels of contamination reported in specific regions, global data on pharmaceutical antibiotic pollution remain uneven and limited. Many low-income countries lack environmental surveillance systems capable of monitoring antibiotic residues and resistance genes, which may lead to an underestimation of the problem.

Antibiotics in wastewater and wastewater treatment

The discharge of antibiotics into water bodies through wastewater from the pharmaceutical industry is a significant factor contributing to the spread of AMR. The concentrations of these antibiotics vary depending on the location and the treatment methods used, with alarming levels in regions such as India and China (Pieri et al., 2020; Kotwani et al., 2021).

Kümmerer (2009) also highlighted the presence of cephalosporins, penicillins, and tetracyclines in pharmaceutical effluents. Cephalosporins, such as cephalexin and cefuroxime, were found in concentrations exceeding 100 μg/l, whereas tetracyclines, especially oxytetracycline, reached up to 50 μg/l in producing regions. These elevated levels are concerning because they may contribute to the development of AMR in aquatic ecosystems (Kümmerer, 2009).

In Europe, Gros et al. (2007) found macrolides and quinolones in wastewater treatment plants (WWTPs), with azithromycin and erythromycin showing concentrations of up to 6 and 15 μg/l, respectively. These antibiotics, which are used to treat human infections, can accumulate in the environment, causing ecological imbalances and promoting the selection of resistant bacteria. The study emphasizes the importance of more effective water-treatment systems to reduce antibiotic release into the environment (Gros et al., 2007).

A 2007 study revealed that the concentration of ciprofloxacin in industrial effluents in Patancheru, India, reached alarming levels of up to 31 mg/l, approximately 1 million times higher than that in treated municipal sewage effluents. These concentrations are toxic to aquatic organisms, with observed impacts on river sediments, groundwater, and drinking water. The total estimated amount of ciprofloxacin released in a single day was equivalent to the daily consumption of a city with 44,000 inhabitants (Larsson, 2014).

Similar situations have been observed in China, where pharmaceutical factories have also released high levels of antibiotics into the environment. In one case, the concentration of oxytetracycline in effluents reached 1,065 mg/l, whereas penicillin G reached 44 mg/l in another study. These examples demonstrate that although the concentrations of pharmaceutical pollutants vary drastically depending on the location and treatment applied, they often exceed the safe levels for environmental health (Qiting and Xiheng, 1988).

Antibiotics released into rivers and soils stimulate the development of resistance genes. Rutgersson et al. (2014) revealed that fluoroquinolone pollution near pharmaceutical factories in India led to the detection of qnr genes in soil and river sediments. The samples indicated that 42% and 7% of well-water and soil samples, respectively, contained these genes. In addition, river sediments in India showed a 100% prevalence of qnr genes, whereas samples from Sweden had a much lower prevalence, at only 18%. Fluoroquinolone concentrations in Indian sediments were extremely high, reaching up to 915.3 µg/g of organic matter, coinciding with the high prevalence of qnr genes (Rutgersson et al., 2014). Qnr genes encode proteins that bind to DNA gyrases and topoisomerase IV, preventing the effective interaction of quinolones with them. This allows bacteria to survive even in the presence of lethal quinolone concentrations (Yusuf et al., 2024).

The issue of antibiotics in wastewater and the effectiveness of sewage treatment in removing these compounds has been widely studied. However, WWTPs worldwide are not specifically designed to remove pharmaceuticals, including antibiotics, resulting in the continuous release of residues into water bodies (Rizzo et al., 2013).

The removal rates of antibiotics in WWTPs significantly vary depending on the technology used and the nature of the antibiotics. Studies in the United States show that the removal of antibiotics in conventional WWTPs ranges between 40% and 90%, depending on the type of antibiotic (Rizzo et al., 2013; Pazda et al., 2019). However, antibiotics such as sulfamethoxazole and ciprofloxacin, tend to be less effectively removed. For instance, a study at a WWTP in the U.S. found that only 30%–50% of sulfamethoxazole was removed, whereas ciprofloxacin had a removal rate of 20%–60% (Watkinson et al., 2009).

The release of antibiotics into water bodies is concerning because they can persist in the environment and cause ecological impacts, including the promotion of bacterial resistance. In a study conducted on the Thames River in the United Kingdom, concentrations of antibiotics such as trimethoprim and ciprofloxacin were detected at levels ranging from 0.3 to 5.0 µg/l in areas near WWTP discharges (Gardner et al., 2012). Although low, this concentration level is sufficient to select resistant bacteria, especially in areas where exposure is chronic.

Aquaculture

Aquaculture is one of the fastest-growing agricultural sectors globally. Currently, this sector accounts for more than half of the world’s seafood production, with an annual growth rate of 6% since 2001. Today, aquaculture accounts for 10% of the global protein consumption, and it is estimated that this percentage will increase to 50% by 2030 (Thornber et al., 2020). The use of antibiotics in aquaculture is a common practice, particularly in intensive systems where fish are raised in high densities. However, the improper or excessive use of these drugs has raised concerns about public health, environmental sustainability, and the development of AMR. (Milijasevic et al., 2024).

As reported by Sapkota et al. (2008), aquaculture uses between 10,000 and 15,000 tons of antibiotics annually worldwide. In regions such as Southeast Asia, antibiotics are used at a rate of 20–80 mg/kg of fish produced (Cabello, 2006). With the significant growth in global aquaculture production, which reached 82 million tons in 2018, the industry’s expansion has brought increased attention to its environmental and health impacts (FAO, 2020). In China, the world’s largest aquaculture producer, approximately 57% of antibiotics are used to treat bacterial diseases in fish. This widespread use raises significant environmental and public health issues, particularly related to the development of AMR (Watts et al., 2017).

In addition, there is a growing concern about the presence of antibiotic residues in the environment and fish. Antibiotic residues are frequently detected in production systems, with 10%–30% of water and sediment samples showing antibiotic residues at levels potentially harmful to microbial ecology. In shrimp farms in Vietnam, up to 70% of sediment samples contained residues of widely used antibiotics such as tetracyclines and sulfonamides (Watts et al., 2017).

Between 2000 and 2018, the prevalence of AMR in compounds with resistance rates above 50% (P50) in farmed aquatic animals remained stable at around 33% between 2000 and 2018, indicating a constant rate of significant resistance. In contrast, wild animals showed a sharp decrease in resistance, dropping from 52% to 22% during the same period (p=0.003). The average P50 resistance index in farmed animals was 31%, whereas it was 44% in wild animals, highlighting a higher rate of resistance among wild species, despite the observed decrease over the years. These data suggest that while resistance in wild animals is declining, farmed animals continue to be a significant reservoir of resistant bacteria, likely due to reduced direct exposure to antimicrobials. This underscores the need for stricter management practices and an integrated approach to controlling the spread of AMR in aquatic ecosystems (Milijasevic et al., 2024).

Adopting good management practices, such as improving environmental conditions and monitoring water quality, as well as adjusting population density to reduce stress in fish and prevent diseases, is essential to avoid the use of antibiotics in aquaculture. These measures can help create healthier systems, reduce the need for antibiotics, and minimize the risk of AMR (Jaime et al., 2012). Vaccines and the application of probiotics and natural additives, such as plant extracts, are also effective strategies to strengthen the immune system of fish and prevent bacterial infections, thereby minimizing the need for antibiotics. These approaches promote animal health and reduce the risk of AMR (Martínez Cruz et al., 2012). In addition, the implementation of strict quarantine programs for new fish batches is a crucial measure to prevent the introduction of pathogens into the production system. This practice helps protect the health of the existing stock and reduces the likelihood of disease outbreaks, thereby minimizing the use of antibiotics in aquaculture (Defoirdt et al., 2007). These integrated measures contribute to aquaculture sustainability and reduce the environmental impact of antimicrobial use. The reliance on antibiotics is minimized by adopting practices that promote fish health and prevent disease, leading to more ecologically responsible and sustainable aquaculture systems.

The impact of aquaculture on AMR also varies geographically. Countries with stricter regulations and vaccination programs tend to demonstrate lower antimicrobial use, whereas intensive production systems in low-regulation settings may contribute disproportionately to the environmental dissemination of resistant microorganisms.

Use in humans

Between 2012 and 2022, antibiotic consumption significantly increased in several countries, with the largest increases observed during the COVID-19 pandemic. Recent data indicate that four broad-spectrum antibiotics accounted for 67% of total consumption in 14 countries studied, and 48 antibiotics used in these regions were not included in the WHO’s essential or recommended medicines lists (Machowska and Stålsby Lundborg, 2018; Malik and Mundra, 2022).

In the European Union, the weighted average consumption of antibacterials for systemic use was 19.4 defined daily doses per 1,000 inhabitants per day in 2022, an increase compared to previous years but a 2.5% reduction compared to 2019. The rise in antibiotic use after the pandemic highlighted the urgent need for policies to encourage innovation in new antibiotics. Between 2017 and 2021, only 12 new antibiotics were introduced to the market between 2017 and 2021, reflecting a low development rate compared to previous decades (Khouja et al., 2022).

AMR was already associated with 4.95 million deaths in 2019, and projections suggest that this number could rise to 10 million by 2050 without proper interventions. In economic terms, AMR is estimated to cause a reduction of 1.1% to 3.8% in global gross domestic product by 2050, particularly affecting low- and middle-income countries, such as those in Sub-Saharan Africa, South Asia, and Latin America (DAVOS, 2024).

The rise in antibiotic consumption over recent decades is a growing concern, primarily due to its direct impact on the development of bacterial resistance. According to Klein et al. (2018), global antibiotic use increased significantly between 2000 and 2015, driven mainly by developing countries. This trend underscores the urgent need for coordinated global efforts to manage antibiotic use and combat AMR (Klein et al., 2018). The rise in antibiotic consumption is particularly concerning in Asia and Africa, where unregulated use has accelerated the emergence of resistant strains. According to data from the WHO, the indiscriminate use of antibiotics, both in healthcare settings and in animal farming, is directly contributing to the growth of AMR, posing one of the greatest challenges to global public health (Estany-Gestal et al., 2024).

As a result of this excessive consumption, bacterial resistance indicators have risen alarmingly worldwide. In 2015, over 670,000 antibiotic-resistant bacterial infections were estimated to have occurred in the European Union and European Economic Area alone, resulting in more than 33,000 deaths. Resistance to antibiotics, such as third-generation cephalosporins and carbapenems, has drastically increased, with bacteria such as Escherichia coli and Klebsiella pneumoniae emerging as major causes of multidrug-resistant hospital infections. The rise in these indicators underscores the urgent need for global interventions and effective public policies to mitigate the indiscriminate use of antibiotics and control the spread of bacterial resistance (Cassini et al., 2019).

To clarify the impact of antibiotic use on the microbiome, the drug resistance index (DRI) was developed. This metric is used to track and assess the effectiveness of antibiotic therapy in each country or region by combining data on antibiotic use with bacterial resistance (BR) rates. The DRI was calculated by multiplying the proportion of each antibiotic used by the observed resistance for each pathogen-antibiotic combination. The index ranges from 0 (100%) to 100 (100%). The primary utility of the DRI is to provide an aggregated view of resistance, enabling comparisons between countries and regions over time. It can be used as a bacterial resistance indicator by correlating antibiotic use with associated resistance, thereby identifying high-risk areas for public health interventions and monitoring the effectiveness of policies aimed at the rational use of antibiotics. (Klein et al., 2019).

Several studies have demonstrated a direct and close relationship between antibiotic use and increased bacterial resistance, a phenomenon that has been extensively documented in the scientific literature. The indiscriminate and excessive use of antibiotics creates a selective environment in which susceptible bacteria are eliminated, allowing the survival and proliferation of resistant strains (Llor and Bjerrum, 2014).

AMR may occur through intrinsic or acquired mechanisms. Intrinsic resistance refers to the natural structural or functional characteristics of bacteria that reduce antibiotic susceptibility, whereas acquired resistance results from genetic mutations or horizontal gene transfer involving plasmids, transposons, and integrons. Excessive antibiotic exposure accelerates the selection and dissemination of resistance determinants across human, animal, and environmental microbiomes (Estany-Gestal et al., 2024).

Bacterial resistance is directly linked to the amount of antibiotics administered within a population. According to the WHO, the greater the use of antibiotics in humans and animals, the higher the likelihood of the development of AMR. In a study conducted by Holmes et al. (2016), bacterial resistance was found to increase proportionally with antibiotic consumption, a problem that is particularly prevalent in countries where antibiotic use is not strictly regulated. Controlling and rationalizing antibiotic use are crucial measures to combat bacterial resistance (Holmes et al., 2016).

The data in the Figure 1 show a strong direct relationship between antibiotic use in various countries and the DRI, confirming the existence of this strong correlation (Antimicrobial consumption in the EU/EEA - Annual Epidemiological Report 2022), Annual Report 2022) This visual representation further emphasizes how increased antibiotic consumption is closely tied to higher resistance levels, as measured by the DRI, reinforcing the need for strict antibiotic regulation and monitoring. The data show a Pearson correlation coefficient of 0.73, which is considered very strong, further supporting the hypothesis that the higher the resistance indices, the more antibiotics are used. This strong correlation emphasizes the need for careful antibiotic management to curb the growing issue of AMR.

Figure 1. Illustrates the correlation between antibiotic consumption and the DRI across different countries. Pearson correlation coefficient (r=0.73).

The data presented in this study underscore the importance of understanding the environmental impact of indiscriminate antibiotic use, especially in light of growing global concerns over AMR. The One Health concept is fundamental for addressing this issue in an integrated manner, highlighting the interdependence of human, animal, and environmental health. The need for urgent measures to reduce environmental contamination is evident, including improving waste-management practices and developing more sustainable antibiotic alternatives.

Simultaneously, more effective regulation of antimicrobial production and use, both in livestock and the pharmaceutical industry, is essential to prevent the continued contamination of ecosystems and protect global health. The involvement of all sectors—government, industry, and society—is crucial for the success of strategies aimed at mitigating the damage caused by AMR.

Human antibiotic consumption also indirectly impacts environmental and animal ecosystems through wastewater release, pharmaceutical disposal, and the circulation of resistant bacteria between communities, healthcare systems, animals, and natural environments. These interactions reinforce the interconnected nature of AMR within the One Health framework.

Implications for public health and policy

The findings of this review reinforce that AMR is not solely a clinical issue but a complex and systemic problem involving environmental, agricultural, and socioeconomic factors. This cross-sectoral strategy highlights the need for integrated policies to regulate antibiotic use across sectors, strengthen environmental monitoring, and promote global cooperation.

Current regulatory frameworks remain fragmented, particularly in low- and middle-income countries, where enforcement is often limited. This gap contributes to antibiotic-residue persistence in ecosystems and the continuous selection of resistant microorganisms.

Therefore, public health strategies must prioritize antimicrobial stewardship programs, stricter regulation of pharmaceutical waste, and incentives for innovation in antibiotic development. In addition, reducing unnecessary antibiotic use in both humans and animals is essential to mitigate the progression of antibiotic resistance.

Finally, this study emphasizes the need to raise global awareness about the role everyone plays in preserving natural resources and maintaining public health. Only through collective commitment and innovative solutions can we reduce the risks associated with excessive antibiotic use and ensure a sustainable future for the next generations.

Harmonized surveillance systems and international agreements regulating antimicrobial use are essential at the global level. At the national level, governments should strengthen antimicrobial stewardship programs, regulate over-the-counter antibiotic sales, and improve wastewater-treatment infrastructure. Locally, educational interventions targeting healthcare professionals, farmers, and the general population may reduce unnecessary antibiotic consumption.

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Conclusion

AMR is a complex and multifactorial global challenge driven by interconnected human, animal, and environmental factors. The evidence presented in this review reinforces that antibiotic misuse across all sectors significantly contributes to the emergence and dissemination of resistant microorganisms. Environmental contamination, particularly through pharmaceutical effluents and wastewater, plays a critical role in sustaining resistance mechanisms in ecosystems. The One Health approach provides a comprehensive and essential framework for addressing these challenges through integrated and coordinated strategies. Effective AMR mitigation requires global commitment, including improved antimicrobial stewardship, stricter regulatory policies, and investment in sustainable alternatives. Without immediate and coordinated action, AMR will continue to pose a serious threat across interconnected human, animal, and environmental systems worldwide.

Future research should prioritize integrated surveillance systems capable of simultaneously monitoring antimicrobial use, environmental contamination, and resistance patterns across human and animal populations. Additional studies evaluating the effectiveness of regulatory interventions and sustainable alternatives to antibiotics are urgently needed.

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Acknowledgments

The author is grateful to the University of Sorocaba.

Conflict of interest

The author declares that there are no competing interests.

Funding

This research received no external funding.

Authors’ contributions

Fernando de Sá Del Fiol was solely responsible for the conception, research, writing, and revision of the manuscript.

Data availability

All data were provided in the manuscript.

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