Antimicrobial resistance (AMR) has become one of the defining health challenges of the twenty-first century. Once-reliable antimicrobial drugs—including antibiotics, antifungals, antivirals, and antiparasitic medications—are increasingly losing effectiveness as microorganisms evolve mechanisms to survive treatment. Although antimicrobial resistance is a natural evolutionary process, human activities have accelerated its development and spread across healthcare, veterinary medicine, agriculture, food production, and the environment (Okeke et al., 2024; Oliveira et al., 2024).

​

Today, antimicrobial resistance affects both human and animal health while creating significant public health, economic, and environmental consequences. Resistant infections contribute to prolonged illness, treatment failure, increased healthcare costs, and higher mortality rates. As bacteria acquire resistance to multiple drug classes, veterinarians, physicians, researchers, and public health agencies face growing challenges in preserving the effectiveness of existing antimicrobial therapies (Huemer et al., 2020; Nusrat et al., 2025).

​

For veterinary medicine, antimicrobial resistance extends beyond individual patient care. Companion animals, livestock, wildlife, food production systems, and environmental reservoirs all participate in the movement of resistant microorganisms and resistance genes. This interconnected nature makes antimicrobial resistance a central topic within the broader One Health framework, which recognizes that the health of humans, animals, and ecosystems cannot be separated (Okeke et al., 2024; Sharma et al., 2024).

​

This educational hub introduces the major scientific concepts surrounding antimicrobial resistance and connects readers with the foundational topics that support responsible antimicrobial use, surveillance, and public health awareness.

​

What This Major Pillar Covers

 

This major pillar provides an evidence-based overview of antimicrobial resistance as it relates to veterinary medicine, animal health, and public health. Rather than focusing on specific diseases or antimicrobial drugs, it explains the biological processes that allow microorganisms to become resistant, the factors driving resistance worldwide, and the coordinated efforts used to monitor and reduce its spread.

​

The page serves as the central hub for three interconnected educational topics:

​

• Understanding Antimicrobial Resistance — explains how resistance develops, why microorganisms evolve resistance mechanisms, and the factors that accelerate this process.

• Antibiotic Stewardship — introduces the principles of responsible antimicrobial use across veterinary and human healthcare while examining how stewardship programs support efforts to preserve antimicrobial effectiveness.

• Surveillance and Monitoring — explores how laboratories, healthcare systems, veterinary networks, and international organizations monitor resistance patterns to guide research, policy, and clinical decision-making.

 

Together, these topics show why antimicrobial resistance is both a biological phenomenon and a complex systems challenge that requires collaboration across multiple disciplines.

​

Why This Area Matters

 

The importance of antimicrobial resistance extends far beyond the effectiveness of individual antibiotics. Modern healthcare and veterinary medicine depend heavily on antimicrobials to treat bacterial infections and to support numerous medical procedures that carry infection risks. As resistance increases, these interventions become harder to manage, less predictable, and sometimes impossible to control effectively.

​

Current evidence identifies antimicrobial resistance as one of the world's leading public health threats. Landmark global estimates from the Global Research on Antimicrobial Resistance (GRAM) project indicate that drug-resistant bacterial infections were associated with approximately 4.95 million deaths annually, including 1.27 million deaths directly attributable to antimicrobial resistance, highlighting the enormous burden imposed by resistant pathogens worldwide (Murray et al., 2022; Okeke et al., 2024).

​

The consequences extend beyond mortality statistics. Resistant infections are consistently associated with:

​

• prolonged illness

• recurrent or relapsing infections

• longer hospitalization

• increased healthcare expenditures

• greater use of advanced or last-line antimicrobial agents

• reduced treatment options for complex infections

 

(Huemer et al., 2020; Oliveira et al., 2024)

 

Particularly concerning is the emergence of multidrug-resistant bacteria such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, which increasingly challenge healthcare systems worldwide. In some regions, resistance to critical last-resort antibiotics—including carbapenems and colistin—has resulted in treatment failure rates exceeding 50% for certain infections (Morris & Cerceo, 2020; Nazir et al., 2025).

​

Veterinary medicine also plays an important role because antimicrobial use occurs across companion animal practice, livestock production, aquaculture, and wildlife medicine. Resistant microorganisms originating in one sector may spread through direct contact, food systems, water, soil, or shared environments, reinforcing the need for coordinated surveillance and stewardship efforts across species and ecosystems (Salam et al., 2023; Okeke et al., 2024).

​

How This Major Pillar Relates to One Health & Public Health Overview

 

Antimicrobial resistance represents one of the clearest examples of the One Health concept in action. Resistant bacteria and antimicrobial resistance genes do not recognize the boundaries between human healthcare, veterinary medicine, agriculture, wildlife, or the environment. Instead, they move continuously among these interconnected systems through multiple transmission pathways.

​

Within animals, resistant bacteria may circulate among companion animals, livestock, wildlife, and production environments. Food production, manure management, wastewater, and environmental contamination may contribute to wider dissemination of resistant microorganisms or resistance genes under certain conditions. Human travel, global trade, and international food supply chains further facilitate the worldwide spread of antimicrobial resistance (Sharma et al., 2024; Oliveira et al., 2024).

​

Research consistently identifies several major drivers that accelerate resistance across One Health sectors:

​

• inappropriate or excessive antimicrobial use

• poor infection prevention and control

• inadequate sanitation and hygiene

• limited access to rapid diagnostics

• environmental contamination with antimicrobial residues

• transmission between humans, animals, and ecosystems

 

(Septimus, 2018; Salam et al., 2023; Sharma et al., 2024)

 

The COVID-19 pandemic further illustrated these connections. Although confirmed bacterial coinfections remained relatively uncommon, antibiotic prescribing often exceeded documented need, raising concerns that unnecessary antimicrobial exposure added selective pressure favoring resistant organisms (Getahun et al., 2020; Nusrat et al., 2025).

​

Because antimicrobial resistance crosses disciplinary boundaries, addressing it requires collaboration among veterinarians, physicians, microbiologists, epidemiologists, environmental scientists, policymakers, agricultural professionals, and public health organizations. This multidisciplinary perspective underpins effective One Health strategies.

​

Key Concepts Within This Pillar

 

Understanding antimicrobial resistance involves several interconnected scientific concepts that explain how resistance develops, spreads, and is monitored.

​

Evolution of resistance refers to the genetic changes that allow microorganisms to survive antimicrobial exposure. These changes may arise through spontaneous mutation or through acquisition of resistance genes from other microorganisms by horizontal gene transfer. Common resistance mechanisms include enzymatic drug inactivation, altered drug targets, reduced membrane permeability, efflux pumps, and biofilm formation (Devi et al., 2024; Nusrat et al., 2025; Abdallah et al., 2026).

​

Selection pressure describes how antimicrobial exposure favors resistant microorganisms while eliminating susceptible organisms. Over time, repeated exposure allows resistant populations to become increasingly dominant within microbial communities (Oliveira et al., 2024).

​

Antimicrobial stewardship focuses on optimizing antimicrobial use through coordinated strategies that promote appropriate prescribing, improve antimicrobial selection, and reduce unnecessary exposure. Evidence suggests stewardship programs improve antimicrobial use, although sustained reductions in resistance often depend on combining stewardship with infection prevention and control measures (Rice, 2018; Septimus, 2018).

​

Surveillance and monitoring provide the data needed to understand where resistance is emerging, which pathogens are affected, and how resistance patterns change over time. Effective surveillance increasingly incorporates human health, veterinary medicine, food systems, and environmental monitoring within an integrated One Health framework (Okeke et al., 2024).

​

These concepts form the foundation for the three major educational topics explored throughout this pillar:

​

Understanding Antimicrobial Resistance

 

Learn how microorganisms develop resistance, the biological mechanisms involved, and the factors that accelerate antimicrobial resistance across animal, human, and environmental systems.

​

Antibiotic Stewardship

 

Explore the principles of responsible antibiotic use and how stewardship programs help preserve antimicrobial effectiveness across veterinary and human healthcare.

​

Surveillance and Monitoring

 

Discover how antimicrobial resistance surveillance helps researchers, veterinarians, clinicians, and public health agencies identify emerging resistance trends and guide evidence-based decision-making.

​

Understanding Antimicrobial Resistance

 

Antimicrobial resistance (AMR) is the ability of microorganisms—including bacteria, viruses, fungi, and parasites—to survive exposure to antimicrobial drugs that were previously effective against them. In veterinary medicine and public health, the greatest concern is antibiotic resistance in bacteria, as resistant bacterial infections continue to increase in frequency, complexity, and global impact (Okeke et al., 2024; Oliveira et al., 2024).

​

Importantly, antimicrobial resistance is not a characteristic of the animal or person receiving treatment. Instead, it is a property of the microorganism itself. When bacteria become resistant, medications that once controlled or eliminated the infection become less effective or may fail altogether. As resistant organisms continue to spread within hospitals, veterinary clinics, farms, communities, and natural environments, managing bacterial infections becomes increasingly difficult for both human and veterinary healthcare systems (Huemer et al., 2020; Nusrat et al., 2025).

​

Although antimicrobial resistance is often described as a modern crisis, resistance itself is an ancient biological phenomenon. Many microorganisms naturally produce antimicrobial compounds to compete with one another, while others have evolved defenses against those compounds over millions of years. What distinguishes today's challenge is the unprecedented selective pressure created by widespread antimicrobial use across medicine, veterinary practice, food animal production, agriculture, and other sectors. This pressure accelerates the survival and expansion of resistant microbial populations beyond what would occur naturally (Christaki et al., 2019; Oliveira et al., 2024).

​

How Antimicrobial Resistance Develops

 

Scientific evidence consistently shows that antimicrobial resistance develops through a combination of genetic change and natural selection. Individual microorganisms occasionally acquire genetic mutations that reduce susceptibility to antimicrobial drugs. In addition, bacteria often exchange resistance genes through horizontal gene transfer, allowing resistance traits to spread rapidly within bacterial populations and, in some cases, across species (Nusrat et al., 2025; Devi et al., 2024).

​

Several well-established molecular mechanisms enable bacteria to withstand antimicrobial exposure:

​

• Enzymatic drug inactivation, in which bacteria produce enzymes that chemically destroy or modify antimicrobial agents before they reach their targets.

• Target modification, where structural changes prevent antimicrobial drugs from binding effectively to bacterial targets.

• Reduced drug uptake, limiting the amount of antimicrobial entering the bacterial cell.

• Efflux pumps, which actively transport antimicrobial molecules out of bacterial cells before they can exert their effects.

• Biofilm formation, creating protective microbial communities that reduce antimicrobial penetration and shield bacteria from host immune responses.

 

These mechanisms often occur simultaneously within the same organism, allowing some bacteria to develop resistance to multiple antimicrobial classes and become multidrug-resistant bacteria (Abdallah et al., 2026; Devi et al., 2024; Nusrat et al., 2025).

​

What Drives Resistance Beyond Biology?

 

While molecular evolution explains how resistance develops, numerous human, animal, and environmental factors determine how quickly resistant organisms emerge and spread. Research consistently identifies antimicrobial use as one of the strongest selective pressures shaping resistance. Every exposure to an antimicrobial agent creates an environment in which susceptible bacteria are more likely to be eliminated while resistant organisms survive and multiply (Oliveira et al., 2024; Septimus, 2018).

​

However, antimicrobial use represents only one part of a much larger system. Current evidence highlights several interconnected drivers of antimicrobial resistance, including:

​

• inappropriate or unnecessary antimicrobial prescribing in human and veterinary healthcare

• antimicrobial use across livestock, companion animals, aquaculture, and crop production

• inadequate infection prevention, biosecurity, and agricultural sanitation

• environmental contamination via agricultural runoff, pharmaceutical manufacturing, and wastewater

• limited access to rapid, point-of-care diagnostic testing

• movement of resistant organisms and genes through humans, animals, trade, and shared ecosystems

 

(Salam et al., 2023; Sharma et al., 2024; Devi et al., 2024)

​

These factors reinforce the importance of viewing antimicrobial resistance through a One Health perspective rather than considering human medicine, veterinary medicine, agriculture, and environmental health as separate issues.

​

Why Antimicrobial Resistance Matters in Veterinary Medicine

 

Antimicrobial resistance in veterinary medicine affects far more than treating individual animals. Companion animals, livestock, wildlife, and aquatic species all exist within interconnected ecosystems where microorganisms, resistance genes, and antimicrobial exposures interact continuously. Resistant bacteria may circulate within animal populations, enter food production systems, contaminate environmental reservoirs, or spread through direct contact between animals and people. Understanding these complex transmission pathways is central to modern veterinary public health and One Health initiatives (Okeke et al., 2024; Sharma et al., 2024).

​

The clinical consequences are substantial. Resistant infections are associated with delayed recovery, prolonged disease, treatment failure, increased healthcare utilization, and higher economic costs across both human and veterinary settings. In addition, antimicrobial resistance threatens the success of medical procedures that rely on effective infection control, including surgery, transplantation, chemotherapy, and intensive care (Huemer et al., 2020; Salam et al., 2023; Oliveira et al., 2024).

​

Among the pathogens receiving significant attention are multidrug-resistant Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, which have become increasingly difficult to manage in healthcare settings. Reports of resistance to critically important antimicrobial agents—including carbapenems and colistin—underscore the urgent need to preserve the effectiveness of existing antimicrobial drugs (Morris & Cerceo, 2020; Nazir et al., 2025).

​

Although antimicrobial resistance is a complex and evolving challenge, the evidence clearly demonstrates that it arises through identifiable biological mechanisms and is amplified by interconnected human, animal, and environmental factors. Building a comprehensive understanding of these processes provides the foundation for the next major topic in this pillar: antibiotic stewardship, which examines coordinated strategies to promote responsible antimicrobial use and reduce unnecessary selection pressure.

​

Antibiotic Stewardship

 

Antibiotic stewardship refers to coordinated, evidence-based efforts that promote the responsible use of antibiotics while preserving their effectiveness for both current and future generations. Within veterinary medicine, stewardship extends beyond reducing antibiotic use alone. It encompasses thoughtful decision-making throughout the entire process of antimicrobial prescribing, administration, monitoring, and evaluation, with the goal of achieving appropriate clinical outcomes while minimizing unnecessary selection pressure for antimicrobial resistance (Rice, 2018; Majumder et al., 2020).

 

Stewardship has become a cornerstone of global antimicrobial resistance strategies because antimicrobial exposure is one of the strongest drivers of resistance evolution. Whenever antibiotics are used, susceptible bacteria are more likely to be eliminated, while resistant organisms have a greater opportunity to survive and multiply. Over time, repeated exposure increases the proportion of resistant bacteria within microbial populations, reducing the effectiveness of available antimicrobial therapies (Septimus, 2018; Oliveira et al., 2024).

Importantly, antibiotic stewardship should not be interpreted as avoiding antibiotic use altogether. Antibiotics remain essential medicines that have transformed both human and veterinary healthcare. Instead, stewardship emphasizes using these valuable medications appropriately, recognizing that preserving antimicrobial effectiveness benefits individual patients, animal populations, and public health simultaneously (Amábile-Cuevas, 2025; Alhassan et al., 2025).

​

Why Stewardship Matters

 

Modern healthcare depends on antibiotics to safely perform many routine and advanced medical procedures. Effective antimicrobial therapy supports surgery, intensive care, organ transplantation, cancer treatment, neonatal medicine, and the management of numerous bacterial infections. As antimicrobial resistance increases, these interventions become progressively more difficult because fewer effective treatment options remain available (Salam et al., 2023; Huemer et al., 2020).

 

Within veterinary medicine, stewardship is equally important. Companion animals, livestock, horses, poultry, aquaculture species, and wildlife all contribute to the broader One Health ecosystem in which resistant microorganisms circulate. Responsible antibiotic use therefore supports not only animal health but also food safety, environmental health, and efforts to reduce antimicrobial resistance transmission between animals and humans (Okeke et al., 2024; Alhassan et al., 2025).

 

Research consistently identifies antimicrobial overuse and misuse as major contributors to resistance. Factors associated with increased resistance pressure include:

 

• unnecessary antimicrobial prescribing

• inappropriate antimicrobial selection

• use of antibiotics when bacterial infection is unlikely

• excessive duration of therapy

• inadequate infection prevention measures

• limited use of diagnostic testing where appropriate

 

These factors interact with poor sanitation, environmental contamination, and transmission between human and animal populations to accelerate resistance development (Septimus, 2018; Salam et al., 2023; Sharma et al., 2024).

​

What Does Antibiotic Stewardship Involve?

 

Although stewardship programs vary across healthcare systems and veterinary settings, they generally share several core principles aimed at optimizing antimicrobial use rather than simply reducing antibiotic consumption.

 

Evidence-based stewardship commonly includes:

 

• promoting appropriate antimicrobial prescribing practices

• encouraging microbiological testing and antimicrobial susceptibility testing when indicated

• reviewing antimicrobial selection as new clinical or laboratory information becomes available

• supporting infection prevention and biosecurity measures

• monitoring antimicrobial use patterns

• educating healthcare professionals, veterinarians, producers, and animal caregivers about responsible antibiotic use

 

(Majumder et al., 2020; Bankar et al., 2022; Giamarellou et al., 2023)

 

An increasingly important component is antimicrobial susceptibility testing, which evaluates how bacterial isolates respond to different antimicrobial agents. These laboratory results help characterize resistance patterns and support evidence-informed antimicrobial decision-making while also contributing valuable data for surveillance programs (Gajić et al., 2022).

 

Stewardship is therefore closely linked with diagnostics, surveillance, microbiology, infection prevention, and public health rather than functioning as an isolated intervention.

​

What Does the Evidence Show?

 

The scientific evidence supporting antibiotic stewardship continues to expand. Multiple systematic reviews demonstrate that stewardship programs consistently improve the quality of antimicrobial prescribing and frequently reduce unnecessary antibiotic use across healthcare settings (Baur et al., 2017; Ya et al., 2023).

 

However, the relationship between stewardship and antimicrobial resistance itself is more complex.

 

Current evidence indicates that stewardship programs reduce antimicrobial exposure and selection pressure, but measurable reductions in resistance rates are not always immediate or uniform across pathogens and healthcare settings. Resistance is influenced by numerous additional factors, including infection prevention, sanitation, transmission dynamics, local epidemiology, environmental reservoirs, and healthcare infrastructure. Consequently, stewardship produces the greatest long-term impact when implemented alongside broader infection prevention and control strategies (Rice, 2018; Septimus, 2018; Bertollo et al., 2018).

 

This interpretation aligns with broader systematic review evidence, which demonstrates that stewardship consistently improves antibiotic prescribing while showing more variable direct effects on reducing environmental and clinical resistance rates in isolation (Baur et al., 2017; Rice, 2018). Researchers consistently conclude that stewardship should be viewed as one component of a comprehensive antimicrobial resistance strategy rather than a standalone solution.

​

Stewardship Within a One Health Framework

 

Antibiotic stewardship has evolved from a hospital-focused initiative into a multidisciplinary concept that spans veterinary medicine, agriculture, environmental health, food production, and public health. Contemporary One Health approaches recognize that antimicrobial decisions made in one sector can influence resistance patterns across many others.

 

For example, resistant bacteria and resistance genes may circulate among companion animals, livestock, wildlife, food products, wastewater systems, and natural ecosystems. Because these pathways are interconnected, stewardship initiatives increasingly emphasize collaboration among veterinarians, physicians, microbiologists, epidemiologists, environmental scientists, policymakers, and agricultural professionals (Delpy et al., 2026; Okeke et al., 2024).

 

The COVID-19 pandemic further highlighted the importance of stewardship. During the pandemic, antibiotic prescribing often exceeded the documented rate of bacterial coinfections, raising concerns that unnecessary antimicrobial exposure added selective pressure for resistant bacteria. This experience reinforced the value of integrating antimicrobial stewardship into preparedness planning for future public health emergencies (Getahun et al., 2020; Langford et al., 2022).

 

As antimicrobial resistance continues to evolve, stewardship remains one of the most important evidence-based strategies for preserving the effectiveness of existing antibiotics. Nevertheless, stewardship alone cannot fully address antimicrobial resistance. Long-term success also depends on comprehensive surveillance systems that can identify emerging resistance patterns, monitor trends over time, and inform evidence-based policy and clinical decision-making.

​

Surveillance and Monitoring

 

Surveillance and monitoring are fundamental components of global efforts to understand and respond to antimicrobial resistance (AMR). While stewardship promotes responsible antimicrobial use, surveillance provides the evidence needed to determine where resistance is emerging, which microorganisms are involved, how resistance patterns change over time, and whether public health interventions have measurable effects. Without reliable surveillance systems, healthcare professionals, veterinarians, researchers, and policymakers have limited ability to detect emerging threats or make informed decisions regarding antimicrobial resistance management (Tacconelli et al., 2017; Okeke et al., 2024).

​

Within veterinary medicine, surveillance extends beyond individual animal health. Resistant microorganisms circulate among companion animals, livestock, wildlife, food products, and environmental reservoirs, making antimicrobial resistance a challenge that spans multiple sectors. Effective surveillance therefore supports both veterinary public health and the broader One Health approach by integrating information from human, animal, food, and environmental systems (Bertagnolio et al., 2023; Oliveira et al., 2024).

​

Why Surveillance Is Essential

​

Antimicrobial resistance is not static. Resistance patterns evolve continuously as microorganisms acquire new genetic adaptations, spread between hosts, and respond to antimicrobial selection pressures. Surveillance lets researchers and public health authorities monitor these changes and identify trends that might otherwise go undetected until resistance becomes widespread.

​

Surveillance data help answer important scientific and public health questions, including:

​

• Which bacterial species are becoming increasingly resistant?

• Which antimicrobial drugs are losing effectiveness?

• Where are resistant organisms emerging geographically?

• Are resistance patterns changing over time?

• Are stewardship and infection prevention efforts influencing antimicrobial use or resistance trends?

• Which populations or animal species require additional monitoring?

 

By addressing these questions, surveillance systems provide an evidence base for research, clinical guidelines, veterinary policies, and public health planning (Diallo et al., 2020; Tacconelli et al., 2017).

​

Surveillance also builds antimicrobial resistance awareness by showing that resistance is not confined to isolated hospitals or veterinary clinics. Instead, it reflects an evolving global pattern influenced by antimicrobial use, transmission pathways, environmental conditions, and international movement of people, animals, and food products (Okeke et al., 2024).

​

How Antimicrobial Resistance Is Monitored

 

Modern antimicrobial resistance surveillance relies on multiple complementary approaches. Clinical microbiology laboratories remain central to these efforts by identifying bacterial pathogens and determining their susceptibility to antimicrobial agents through antimicrobial susceptibility testing (AST). These laboratory results provide standardized information on whether bacterial isolates remain susceptible, show reduced susceptibility, or exhibit resistance to specific antimicrobial drugs (Gajić et al., 2022).

​

When combined across hospitals, veterinary diagnostic laboratories, public health agencies, and research networks, antimicrobial susceptibility data reveal broader resistance patterns not apparent from individual cases alone. Surveillance programs increasingly incorporate molecular epidemiology, whole-genome sequencing, and genomic analyses to identify resistance genes, characterize transmission pathways, and monitor the emergence of high-risk bacterial lineages (Boolchandani et al., 2019; Sherry et al., 2025).

​

These advances have improved understanding of how resistance develops and spreads while supporting more detailed investigation of multidrug-resistant organisms.

​

A One Health Perspective on Surveillance

 

Current research increasingly emphasizes that surveillance should extend well beyond healthcare facilities. Although hospital-based monitoring remains essential, antimicrobial resistance also develops and circulates in food production systems, livestock operations, companion animals, wildlife populations, wastewater, soil, and aquatic environments. Surveillance limited to clinical settings therefore captures only part of the overall picture.

​

Recent reviews identify surveillance breadth as a major knowledge gap in antimicrobial resistance research. Experts consistently recommend expanding surveillance systems to integrate human health, veterinary medicine, food safety, agriculture, and environmental monitoring within a coordinated One Health framework (Okeke et al., 2024; Khadse et al., 2023).

​

This integrated approach recognizes that resistant microorganisms and resistance genes move through interconnected ecological pathways. Food animals, companion animals, wildlife, wastewater systems, and environmental reservoirs may all contribute to the persistence and dissemination of antimicrobial resistance under different circumstances. Coordinated surveillance across these sectors therefore provides a more comprehensive understanding of resistance dynamics than isolated monitoring programs alone (Lim et al., 2021; Iskandar et al., 2021).

​

Challenges and Future Directions

 

Despite substantial progress, antimicrobial resistance surveillance still faces important challenges. Many surveillance systems remain concentrated in hospitals and high-income countries, while data from community settings, veterinary medicine, food production, and environmental sources remain comparatively limited. Differences in laboratory capacity, diagnostic methods, reporting standards, and data-sharing infrastructure further complicate cross-regional comparisons (Iskandar et al., 2021; Oldenkamp et al., 2020).

​

Recent reviews also emphasize the need for surveillance systems that provide representative population-level data rather than relying primarily on selected hospital populations. Broader geographic coverage, standardized laboratory methods, better integration of veterinary and environmental surveillance, and expanded genomic monitoring are priorities for strengthening future antimicrobial resistance surveillance programs (Van Leth & Schultsz, 2022; Van Kessel et al., 2025).

​

As surveillance technologies continue to evolve, they are expected to play an increasingly important role in identifying emerging resistance threats, informing antimicrobial stewardship programs, supporting public health policy, and advancing One Health research.

​

Current Research Themes

 

Antimicrobial resistance remains one of the most active areas of global biomedical and veterinary research. While decades of investigation have clarified many biological mechanisms underlying resistance, important questions remain about how to prevent, monitor, and manage resistance across increasingly interconnected human, animal, and environmental systems.

​

Based on the evidence summarized in this research corpus, several major themes shape contemporary antimicrobial resistance research.

​

Molecular Mechanisms of Resistance

 

The strongest body of evidence focuses on the molecular biology of antimicrobial resistance. Numerous reviews consistently describe horizontal gene transfer, target modification, enzymatic drug inactivation, efflux pumps, reduced membrane permeability, and biofilm formation as the principal mechanisms by which bacteria evade antimicrobial activity (Nusrat et al., 2025; Abdallah et al., 2026).

​

Understanding these mechanisms continues to guide the development of new diagnostic technologies and future antimicrobial therapies.

​

Expanding One Health Surveillance

 

Another major research priority is expanding antimicrobial resistance surveillance beyond hospitals into animal populations, food systems, and environmental reservoirs. Researchers consistently emphasize that integrated One Health surveillance provides a more accurate understanding of how resistant microorganisms circulate across interconnected ecosystems than healthcare-only monitoring programs (Okeke et al., 2024; Bertagnolio et al., 2023).

​

Optimizing Antibiotic Stewardship

 

Stewardship research increasingly examines how responsible antimicrobial use can be integrated with infection prevention, diagnostic stewardship, surveillance, and healthcare quality improvement. Current evidence shows that stewardship consistently improves antimicrobial prescribing, but researchers continue to investigate which combinations of interventions produce the greatest long-term reductions in antimicrobial resistance across settings (Rice, 2018; Baur et al., 2017).

​

Novel Therapeutic Approaches

 

Researchers are actively exploring innovative strategies that complement or extend traditional antimicrobial therapy. Emerging areas include bacteriophage therapy, CRISPR-based antimicrobial technologies, antimicrobial adjuvants, and inhibitors targeting bacterial resistance mechanisms. Although these approaches have shown considerable scientific promise, current reviews note that further research is needed to address challenges related to safety, effectiveness, dosing, implementation, and real-world clinical application before widespread adoption can occur (Abdallah et al., 2026; Pilar et al., 2025).

​

Addressing Knowledge Gaps

 

Despite extensive research activity, several important evidence gaps remain. Long-term outcomes following stewardship interventions, comprehensive surveillance across animal and environmental reservoirs, implementation of novel antimicrobial technologies, and standardized global surveillance systems all require additional investigation. Continued collaboration among veterinarians, physicians, microbiologists, epidemiologists, environmental scientists, and public health agencies will be essential for strengthening the evidence base supporting future antimicrobial resistance strategies (Okeke et al., 2024; Oliveira et al., 2024).

​

Together, these research themes reinforce that antimicrobial resistance is not a single clinical problem but a complex global challenge requiring coordinated scientific investigation across multiple disciplines and sectors.

​

Frequently Asked Questions

 

What is antimicrobial resistance?

​

Antimicrobial resistance (AMR) is the ability of microorganisms—including bacteria, viruses, fungi, and parasites—to survive exposure to antimicrobial drugs that would normally inhibit or eliminate them. In veterinary medicine and public health, the greatest concern is antibiotic-resistant bacteria, which can make infections harder to treat and increase the risk of treatment failure, prolonged illness, and disease transmission (Okeke et al., 2024; Oliveira et al., 2024).

​

What causes antimicrobial resistance in animals?

​

Antimicrobial resistance develops through natural evolutionary processes, but antimicrobial use accelerates its emergence and spread. Additional contributing factors include inappropriate antimicrobial prescribing, inadequate infection prevention, poor sanitation, environmental contamination, and movement of resistant microorganisms between animals, humans, and ecosystems (Septimus, 2018; Sharma et al., 2024).

​

How does antimicrobial resistance develop?

​

Resistance develops when microorganisms acquire genetic mutations or obtain resistance genes from other microorganisms through horizontal gene transfer. These changes enable bacteria to survive antimicrobial exposure using mechanisms such as enzymatic drug inactivation, target modification, reduced drug uptake, efflux pumps, and biofilm formation. Repeated antimicrobial exposure increases selection pressure, allowing resistant organisms to become more common within microbial populations (Nusrat et al., 2025; Devi et al., 2024).

​

Why is antibiotic stewardship important?

​

Antibiotic stewardship promotes responsible antimicrobial use while preserving the effectiveness of existing antibiotics. Research consistently shows that stewardship programs improve antimicrobial prescribing and reduce unnecessary antimicrobial exposure. Although stewardship alone cannot eliminate antimicrobial resistance, it forms an essential component of broader strategies that also include infection prevention, surveillance, and public health collaboration (Rice, 2018; Baur et al., 2017).

​

How does antimicrobial resistance affect human and animal health?

​

Antimicrobial resistance increases the likelihood of treatment failure, prolonged illness, recurrent infections, hospitalization, and higher healthcare costs. It also threatens medical procedures that depend on effective antimicrobial therapy, including surgery, chemotherapy, transplantation, and intensive care. Because resistant microorganisms circulate among humans, animals, and the environment—contributing to over 1.2 million directly attributable deaths globally each year—antimicrobial resistance is recognized as a major One Health challenge (Murray et al., 2022; Salam et al., 2023).

​

What is antimicrobial resistance surveillance?

​

Antimicrobial resistance surveillance is the systematic collection, analysis, and interpretation of data describing antimicrobial resistance patterns over time. Surveillance supports veterinary medicine, human healthcare, research, and public health by identifying emerging resistance trends, informing stewardship efforts, and guiding future policy development (Tacconelli et al., 2017; Bertagnolio et al., 2023).

​

Explore Related Topics

 

Continue exploring the One Health & Public Health Overview knowledge system through these connected educational resources:

​

• One Health & Public Health Overview

• Understanding Antimicrobial Resistance

• Antibiotic Stewardship

• Surveillance and Monitoring

 

Together, these pages explain how antimicrobial resistance develops, how responsible antimicrobial use supports stewardship efforts, and how surveillance systems help protect animal, human, and environmental health through an integrated One Health approach.