eChapters

Mange or parasitic dermatitis is caused by the infestation of mange mites e.g. Sarcoptes, Psoroptes, Demodex spp. and a range of other mites. The condition is characterized by itching and rubbing of the infested parts of the body against hard objects. Lesions include hair loss, dry, rough, thickened and wrinkled skin accompanied by the presence of scab and foul odour in some cases. Some mites burrow into the host epidermis (Sarcoptes) while others spend their entire life cycle on the skin surface (Psoroptes). Most mites are microscopic or less than 1mm in length; therefore skin scrapings are taken from the affected area of animals suspected to be suffering from mange or parasitic dermatitis

HELMINTHS Collection of parasites Fresh helminth parasites should be collected, as far as possible to achieve better results in staining. This can best be done by conducting a post-mortem examination of the animal for which the procedure given below should be followed. On opening the body and before removal of the viscera, examine the body cavity (for free lying parasites, e.g. Setaria), subcutaneous tissue (for Parafilaria and Hypoderma larvae) and the surfaces of internal organs for spot or nodules that might contain parasites. Remove them for histopathological examination (in 10 % formalin). Remove the visceral organs separately and place them in different enamel trays.

Diagnosis of parasitic infections is routinely done with conventional parasitological techniques as described earlier. However, when the parasitaemia is too low to be detected by the conventional methods as in subclinical infections and/or carrier animals advanced diagnostic tools are used for the early, sensitive as well as specific diagnosis. Serological techniques Diagnostic techniques used mostly in laboratories needs various reagents and equipments to perform the test. However, a diagnostic kit is the extrapolation of the same method by packing it in a user friendly format, accompanied by all or most of the reagents required to perform the test and can also be done outside the lab or under field conditions. Various immunodiagnostic kits are available which are based on different diagnostic methods like Enzyme-linked immuno sorbent assay (ELISA). Complement fixation test (CFT), Agar gel immunodiffusion test (AGID), Immunofluorescent tests (IFT), Latex agglutination tests (LAT) etc. ELISA is the most commonly used test system and numerous kits based on ELISA are available commercially.

Introduction 
Antimicrobial resistance (AMR) is one of the most significant global health challenges of the 21st century. Defined as the ability of microorganisms— including bacteria, viruses, fungi, and parasites—to resist the effects of antimicrobial drugs, AMR undermines the progress of modern medicine. Antimicrobials—including antibiotics, antivirals, antifungals, and antiparasitics—are the cornerstone of modern medicine. Their discovery transformed the treatment of infectious diseases and enabled surgical advances, chemotherapy, and organ transplantation. However, Alexander Fleming, the discoverer of penicillin, warned that misuse could render these drugs ineffective. Antibiotics, since their discovery in the 20th century, revolutionized healthcare, saving millions of lives and enabling complex medical procedures. Yet, the misuse and overuse of antimicrobials in human health, veterinary practices, and agriculture have rapidly accelerated the emergence of resistant organisms. Today, this warning has materialized as a global crisis. Antimicrobial resistance (AMR) is now considered one of the top ten public health threats by the World Health Organization (WHO). It is not only a biomedical issue but also a socio-economic and developmental challenge. This chapter aims to provide an in-depth overview of AMR, focusing on definitions, history, mechanisms, causes, global status, impacts, and the urgency of mitigation efforts. It also explores national and global responses and future directions to curb the spread of AMR. AMR is estimated to cause 700,000 deaths annually worldwide, with projections of 10 million deaths annually by 2050 if urgent interventions are not implemented. In addition to health impacts, AMR poses grave threats to food security, sustainable agriculture, economic stability, and global development. This chapter provides a comprehensive overview of AMR, including definitions and conceptual frameworks, historical background, mechanisms of

Introduction

Until the 20thcentury, bacterial infections were the number one cause of human death. In the 1940s, antibiotics became the lifelines for treating serious infections that saved millions of lives. Despite the advantages derived from the use of antibiotics, resistance to these drugs emerged. Unfortunately, resistance to most antibiotics emerged in time-course even for the most powerful antibiotics developed.Resistance to antibiotics is a challenge to the scientific community in keeping up the pace of antibiotic discovery.World Economic Forum’s Global Risks Reporthas listed antibiotic resistance as one of the greatest threats (WEF, 2020).United Nations (UN) has warned that drug-resistant diseases could account for 10 million deaths each year by 2050. By 2030, antimicrobial resistance (AMR) could likelylead up to 24 million people into extreme poverty(IACG,2019). Currently, at least 7,00,000 people die each year due to drug-resistant diseases (IACG,2019). The emergence and widespread of antibiotic-resistant organisms is a global challenge and needs a multi-dimensional approach to address the fundamental issues to minimize drug-resistance.The Antibiotic Resistance Genes Database (ARDB) contains a repository of around 23,000 antibiotic resistance gene or protein sequences conferring resistance against over 240 antibiotics (ARDB). Computational Biology (Bioinformatics) has become one of the important tools in studying antimicrobial resistance. It employs a range of computation techniques to make predictions about the biological phenomenon.

A. Evaluation of the efficacy and resistance of anthelmintics against Helminths Anthelmintic resistance According to WAAVP (World Association for the Advancement of Veterinary Parasitology) anthelmintic resistance is a failure to reduce feacal nematode egg count by at least 95%. Technically accurate definition is that resistance is a genetically determine decline in the efficacy of an anthelmintic against a population of parasite that is susceptible to the drug. The history of parasite resistance to anthelmintic starts with the first report on phenothiazine resistance in 1957. Haemonchus contortus was the first nematode to develop resistance against different anthelmintic. The World Association for the Advancement of Veterinary Parasitology has recommended two tests for detecting anthelmintic resistance in ruminants, horses and pigs. These are in vivo test (FECRT) and an in vitro test (the egg hatch test). Detection Technique

Introduction

The epidemiological risk and hazards to global health security posed by AMR has been reiterating in several World Health Assembly (WHA) declarations and has been prioritized under the Global Health Security Agenda (GHSA). The Indian Ministry of Health & Family Welfare (MoHFW) has also identified AMR as one of the top priorities for collaborative work with WHO and the first National Action Plan on AMR has been implemented (2017-2022). India ranked fifth in antibiotic consumption in food producing animals (ruminants, pigs, and poultry) in 2010. Even though there has been a gradual reduction of 3.6% in antibiotic consumption during 2011-2019 (Koya et al., 2022), with mounting incomes and shifting in dietary patterns in favour of the consumption of animal protein, especially for poultry, the veterinary antibiotic utilization is projected to further rise by 312%, elevating India to the fourth rank by 2030 (Van Boeckel et al., 2015). FAO has already reported some of the peak resistance rates among common commensal and environmental bacteria against antibiotics like penicillin, cephalosporins, erythromycin and co-trimazoles in India (INFAAR). Resistance to the broad spectrum fluoroquinolones and third generation cephalosporin antibiotics is already more than 70% in Escherichia coli, Klebsiella pneumoniae, and, Acinetobacter baumannii and more than 50% in Pseudomonas aeruginosa. Even the microbial resistance to carbapenems, the last-resort antibiotics, is extremely high among gram-negative microorganisms (Sumanth et al., 2016). To overcome these incidences, it is impulsive to understand the microbe and drug interaction in host system.

Introduction
Antimicrobial resistance (AMR) is one of the top global public health threats. It is estimated that bacterial AMR was directly responsible for 1.27 million global deaths in 2019 and contributed to 4.95 million deaths (Murray et al., 2019).Despite its magnitude, public awareness of AMR remains low. Unlike tobacco smoke, antibiotics are potentially life-saving medications, but it is just as vital to understand the risks of overuse and their impact on future effectiveness in society as a whole (Langfordet al., 2019). Effective risk communication is essential to addressing AMR because it not only informs professional and community stakeholders but also nurturesbehaviour change across sectors. Within a One Health framework, risk communication connects human medicine, veterinary practice, agriculture, and environmental management, ensuring coordinated responses to reduce misuse and overuse of antimicrobials. This article explores the role of risk communication in combating AMR, highlighting global lessons, challenges, and strategies to strengthen communication systems for sustainable containment.
The Growing Threat of AMR
AMR occurs when microorganisms such as bacteria, viruses, fungi, and parasites evolve mechanisms to resist drugs that once effectively treated them. Misuse and overuse of antimicrobials in human health, livestock, aquaculture, and crop production accelerate resistance. According to WHO, AMR is projected to cause 10 million deaths annually by 2050 if left unaddressed (O’Neill, 2016). In countries like India, with high infectious disease burdens and large-scale antimicrobial consumption, the risks are particularly acute. Communicating these risks clearly and effectively is critical for influencing prescribing practices, agricultural use, and community awareness.Persistent misconceptions include beliefs that antibiotics are effective against viral illnesses and the mistaken notion that it is the human body, rather than bacteria, that develops resistance (Muflihet al., 2021). These knowledge gaps are often linked to insufficient or ineffective health communication (Krockowet al., 2023), sparse media coverage compared to threats like sepsis (Fitzpatrick et al., 2019).
Challenges in AMR Risk Communication
1. Low Public Awareness: Despite the global severity ofAMR, public awareness remains critically low. Surveys have found that a mere fraction of the population grasp its implications, with some reporting only ~8–11% demonstrating adequate understanding and many feeling powerless to contribute (Goshaet al., 2024).
2. Ineffective understanding of Terminology: It is recognized that AMR has a ‘language problem’ and the way in which healthcare professionals communicate about AMR may not always resonate with patients (Langford et al., 2019). Technical labels like “AMR” or “antimicrobial resistance” fall short in public communication. Experiments reveal that phrases such as “Antibiotic Resistance” or “Antibiotic Crisis” are more memorable and better at promoting critical behaviors—like completing prescribed antibiotic courses—than more formal terminology.
3. Misconceptions about Antibiotics: Widespread misunderstandings persist regarding antibiotics’ purpose and effect. Many incorrectly believe antibiotics treat viruses—common colds, flu, or even are effective painkillers (Gunasekara et al., 2022).Some think AMR occurs because the body becomes resistant, rather than bacteria evolving resistance(Muflihet al., 2021).
4. Complexity of the Issue: AMR is inherently multifaceted—spanning interactions among humans, animals, and the environment—which makes it challenging to distill into clear, actionable messages. Understanding Risk

The mycoplasmas are microorganisms in the class Mollicutes. Of the nine genera in this class, five contain species of veterinary interest. The genus Mycoplasma, in which there are about 100 species, contains most of the animal pathogens. The first mycoplasma identified in 1890 was Mycoplasma mycoides subspecies mycoides, the cause of contagious bovine pleuropneumonia. Similar types of mycoplasmas which were subsequently identified were called pleuropneumonia- like organisms (PPLO).
Mycoplasmas, the smallest prokaryotic cells capable of self-replication, are pleomorphic organisms ranging from spherical (0.3 to 0.9 pm in diameter) to filamentous (up to 1.0 μm long). Because they cannot synthesize peptidoglycan or its precursors, they do not possess rigid cell walls but have flexible, triplelayged outer membranes.
Their flexibility allows them to pass through bacterial membrane filters of pore size 0.22 to 0.45 μm. Mycoplasmas are susceptible to desiccation, heat, detergents and disinfectants. However, they are resistant to antibiotics such as penicillin which interfere with the synthesis of bacterial cell walls. Based on 5s rRNA sequence analyses, the mycoplasmas have been shown to be linked phylogenetically to Gram-positive bacteria such as Clostridium species which have low guanine-cytosine content in their DNA. They require enriched media for growth, characteristically forming umbonate micro-colonies
when illuminated obliquely and microcolonies with a ‘fried egg’ dppearance in transmitted light. The dense central zone is due to extension of the microcolony into the agar. Mycoplasmas, which have relatively small genomes (approximately 800 genes) are fastidious in their growth requirements.
Most mycoplasmas are facultative anaerobes and some grow optimally in an atmosphere of 5 to 10% CO2. Nonpathogenic anaerobic mycoplasmas are found in the rumens of sheep and cattle. The genera Mycoplasma and Ureaplasma contain animal pathogens.

Introduction
Q fever is a zoonotic bacterial infection caused by Coxiella burnetii, an obligate intracellular parasite, classified within the family Rickettsiaccae. Q fever (Q for “query”) was first used in 1937 to describe a mysterious febrile illness of packing house workers in Brisbane, Australia. The causative agent was isolated from infected workers and later was identified as Rickettsiae. Almost simultaneously the same organism was identified wood tick collected in Montana. Cox, an American, and Burnet, an Australian, where honored for their early work with this organism, hence the name “Coxiella burnetii”.
Host and Susceptibility
Coxiella burnetii is a well-established infectious agent that has reached a state of balanced pathogenicity in a plethora of host. Human are unnatural and usually dead-end-host. The microorganism generally maintained in a less pathogenic form in separate cycle existing independently among wild mammals and their haematophagus arthropods, principally tick and in domestic animals.
Morphology
It is an intracellular organism which is a polymorphic bacillus (0.2-0.4mm width, 0.4-1.0 mm length), which has a cell membrane, like Gram negative bacteria. However, it stains poorly with pigmented Gram stain, but gimenez staining is traditionally used to stain the Coxiella burnetii pathogen from pathological materials and crop. Coxiella burnetii has several distinctive characteristics, including a sporulationlike
process that protects the organism against the external environment, where it can survive for long periods. In mammals, the usual host cell of C. burnetii is the macrophage, which is unable to kill the bacterium. The other an important characteristic of C. burnetii is its antigenic variations, those called phase variation. This antigenic shift can be measured and is valuable for differentiating acute from chronic Q fever. Thus, it displays two antigenic phases those are phase-I and phase- II that are liable to the Lipopolysaccharide (LPS) of the membrane.

Introduction
India has been making steady progress in the livestock sector with significant rise of meat, egg and milk production and a sustained annual growth rate of more than 5%. This growth trajectory is anticipated to accelerate further due to rising middle-class incomes combined with high income elasticity of demand for livestock products. However, despite having huge livestock resource, protein deficiency in rural India remains widespread. Recent data shows that two third of the Indian households are deficient in protein intake1. Looking at the growth potential in the sector, Govt. of India has put special focus on this sector and have undertaken many initiatives to boost animal health productivity and to increase farmer’s income. However, a major limiting factor in profitable livestock production in India is the high prevalence of infectious diseases. These livestock diseases cause great socioeconomic impact and are often exacerbated by inadequate biosecurity measures both in intensive and open production systems. Consequently, the use of antimicrobials for disease treatment has become an essential aspect of livestock management. Antibiotics usage in Animal Healthcare Antibiotics are an essential part of therapeutic management of infectious diseases in both farm and companion animals, ensuring better animal health and life; thereby also assures healthy food from the animal sources. In India a wide range of antibiotics are available in the veterinary practice viz. Penicillin, Semi-synthetic penicillin like Ampicillin, Amoxycillin, Aminoglycosides like Streptomycin, Gentamicin, Neomycin; Tetracycline, Kanamycin, Erythromycin; Fluoroquinolones like Enrofloxacin, Norfloxacin, Ciprofloxacin,

Bacteria from the genus Anaplasma belong to the Procaryota kingdom, the family Anaplasmataceae. Anaplasma belong to obligate intracellular microorganisms, Gram-negative bacteria, living in the blood cells of mammals. Vertebrates can be their reservoir, i.e. an environment where the pathogen can live and proliferate for many years. However, in many cases bacteria from the genus Anaplasma cause diseases in domestic animals and people.
Taxonomical Position of Bacteria from the Genus Anaplasma
The genera Anaplasma, Ehrlichia, Neorickettsia and Wolbachia include obligate intracellular bacteria, parasitizing in the vacuoles of cells in eukarytic hosts. Animal pathogens were attributed to the genus Anaplasma, such as A. centrale, A. marginale, A. platys, A. ovis and A. bovis, and also the aetiological factor of human anaplasmosis, A. phagocytophilum.
Anaplasma marginale
A. marginale are obligate intracellular bacteria parasitizing in erythrocytes of higher vertebrates, mostly ruminants.
Anaplasma Centrale
A. centrale is a parasite in the erythrocytes of ruminants, mainly cattle. As opposed to A. marginale, it creates concentrations in the central part of the cell. A. centrale is less pathogenic to cattle than A. marginale but, most importantly, occasionally gives resistance against the latter. Hence it is used for the preparation of live vaccine strains, assuring immunological protection against bovine anaplasmosis.
Anaplasma Bovis
A. bovis is a bacterium detected mainly in cattle, but also observed in small mammals which are probably a reservoir of this bacterium. It occurs in monocytes, and the disease it causes is called monocytic anaplasmosis. The symptoms of the disease are most visible in calves, but also in adult animals; symptoms include weakening of the body, marked reduction in weight, elevated temperature, enlargement of prescapular lymph nodes, paling of the mucous membranes, and in many cases an elevated amount of secreted mucus.

Organisms in the order Rickettsiales form a diverse group of small (0.3 to 0.5 x 0.8 to 2.0 pm), non-motile, pleomorphic Gram-negative bacteria which replicate only in host cells. They can be cultured in the yolk sac of embryonated eggs or in selected tissue culture cell lines. Because they stain poorly with aniline dyes, these organisms should be stained by Romanowsky methods such as Giemsa or Leishman. In addition to host-cell dependence and poor affinity for basic dyes, a requirement for an invertebrate vector distinguishes them from conventional bacteria and the Chlamydiales.
Epidemiology
Animal hosts and arthropod vectors are the reservoirs for most rickettsiae. A number of rickettsia1 organisms, including Ehrlichia canis, Anaplasma marginale and Haemobartonella felis produce latent infections. In arthropods, rickettsiae replicate in the epithelial cells of the gut before spreading to other organs, including the salivary glands and ovaries where further replication may occur.
Organisms are transmitted when the arthropod feeds on the animal host. Some organisms such as Rickettsia rickettsii are maintained in a tick population by transovarial transmission. Trans-stadial but not transovarial transmission of E. canis and E. phagocytophila occurs in ticks. With the exception of Coxiella burnetii, which produces endospore-like forms and can remain viable in dust for up to 50 days, most rickettsiae are labile outside host cells. Aerosol transmission of C.burnetii commonly occurs in domestic animals and humans. In addition, a silent cycle involving ticks and small wild mammals may constitute a possible source of infection for some domestic species.
Pathogenesis and Pathogenicity
Many Rickettsia species including the causal agents of typhus (R. prowuzekii), murine typhus (R. typhi) and scrub typhus (R. tsutsugamushi) are primarily human pathogens. Rocky Mountain spotted fever, caused by Rickettsia rickettsii, which is a common rickettsia1 disease of humans, also affects dogs.

Chlamydiae are obligate intracellular bacteria with an unusual developmental cycle during which unique infectious forms are produced. They replicate within cytoplasmic vacuoles in host cells. On account of their apparent inability to generate ATP, with resultant dependence on host cell metabolism, they have been termed ‘energy parasites’.
The family Chlamydiaceae belongs to the order Chlamydiales. Currently two genera, Chlamydia and Chlamydophila, and nine species are described. Formerly a single genus and four species, Chlamydia trachomatis, C. psittaci, C. pneumoniae and C. pecorum, were recognised. This classification was based on phenotypic characteristics such as host preference, inclusion morphology, iodine staining for the presence of glycogen, and sulphonamide susceptibility. However, recent nucleic acid sequencing studies of the 16s and 23s rRNA genes confirm two distinct lineages.
In the developmental cycle of chlamydiae, infectious and reproductive forms are morphologically distinct. Infectious extracellular forms, called elementary bodies (EBs) are small (200 to 300 nm), metabolically inert and osmotically stable. Each EB is surrounded by a conventional bacterial cytoplasmic membrane, a periplasmic space and an outer envelope containing lipopolysaccharide.
The periplasmic space does not contain a detectable peptidoglycan layer and the EB relies on disulphide cross-linked envelope proteins for osmotic stability. Elementary bodies enter host cells by receptor-mediated endocytosis. Acidification of the endosome and fusion with lysosomes are prevented by mechanisms which are not fully understood. A process of structural reorganization within the pathogen, of several hours duration, results in the conversion of an EB into a reticulate body (RB). The RB, about 1 μm in diameter, is metabolically active, osmotically fragile and replicates by binary fission within the endosome. The endosome and its contents, when stained, is called an inclusion. When a number of inclusions containing RBs of C.trachomatis are formed in an infected cell, fusion of these structures may
occur.

Introduction
Antimicrobial resistance (AMR) is rapidly emerging as one of the most critical global health challenges of the 21st century. Antimicrobial resistance can be defined as a condition in which microbes develop resistance against the spectrum of conventional antibiotics, also known as multidrug resistance and these microbes are typically known as drug-resistant pathogens. The infections associated with antibiotic resistant pathogens are usually accompanied by substantial morbidity and mortality along with the massive economic burden on global healthcare, which causing approximately 4.95 million deaths globally each year. The prevalent issue is largely attributed to the repercussions of antimicrobial overuse or irresponsible utilization across diverse contexts, predominantly in clinical treatment, agricultural practices, animal healthcare, war crisis and the food system and a lack of regulation in their supply. Nature has long been a rich reservoir of biologically active compounds with diverse chemical structures and pharmacological properties, offering valuable resources for treating a wide array of diseases. In recent years, the rising threat of antimicrobial resistance has renewed global interest in natural products as promising sources for novel antimicrobial agents. Among these, plant-derived phytochemicals, microbial metabolites, marine bioactive compounds, and animal-based substances have shown significant potential in combating drug-resistant pathogens. These natural compounds exhibit unique mechanisms of action that can overcome existing resistance pathways, making them important candidates in the development of nextgeneration antibiotics. From alkaloids and flavonoids in medicinal plants to secondary metabolites produced by actinomycetes, antimicrobial peptides from animals, and complex molecules derived from marine organisms, nature offers a vast and largely untapped arsenal of antimicrobial agents. Exploring and harnessing these natural resources presents a sustainable and innovative strategy to address the growing global crisis of antimicrobial resistance. The enormous potential of natural products in the fight against antibiotic resistance is examined in this chapter. The different kinds of bioactive chemicals, their modes of action, and the creative approaches being used to maximize their medicinal potential are highlighted.
Challenges in Addressing AMR with Conventional Methods
1. Weak Implementation of National Action Plans: Only a small percentage of the more than 170 nations that have created AMR action plans have operationalized them with specialized financing and monitoring mechanisms. This leads to a gap between policy and practice, especially in low- and middle-income nations.
2. Restrictions in the Management of Antimicrobials: Lack of qualified staff, insufficient microbiological assistance, and shoddy governance frameworks are some of the common obstacles that antimicrobial stewardship initiatives must overcome. Due to the lack of quick diagnosis, broad-spectrum antibiotics are still empirically used in many hospitals.
3. Diagnostic Barriers: Rapid diagnostic methods are still few, and traditional culture-based susceptibility testing is sluggish. Resistance selection is accelerated by this diagnostic latency, which frequently forces physicians to use broad-spectrum empirical treatment.
4. Surveillance Gaps: Despite the growth of programs like the Global Antimicrobial Resistance and Use Surveillance System (GLASS), data quality and surveillance coverage are still uneven. The inability of many nations to track resistance in important diseases compromises prompt policy responses.
5. Limited Innovation in Drug Development: Only a few new types of antibiotics are now in advanced clinical development, making the pipeline still rather thin. Under the present traditional paradigm, pharmaceutical innovation is discouraged by market failure due to low return on investment.

Introduction
Antimicrobial resistance (AMR) is rapidly becoming one of the most critical challenges in global health, with profound implications for both human and veterinary medicine. The increasing prevalence of drug-resistant bacterial infections has eroded the effectiveness of many frontline antibiotics, making even routine treatments more complex and less predictable. Surveillance data from the World Health Organization’s GLASS initiative highlights the scale of the problem: resistance to third-generation cephalosporins in Escherichia coli and methicillin in Staphylococcus aureus has reached alarming levels in dozens of countries, complicating the management of common infections and raising the stakes for therapeutic innovation. In veterinary settings, the crisis is equally urgent. Resistance has emerged across nearly all major antibiotic classes used in livestock, poultry, and companion animals. Contributing factors include widespread antibiotic use in agriculture, limited diagnostic stewardship, and the ease with which resistance genes spread within and between microbial communities. These trends not only threaten animal health and productivity but also increase the risk of zoonotic transmission, blurring the boundaries between veterinary and human public health. Global health authorities have long warned of a “post-antibiotic era” - a time when conventional antibiotics may no longer offer reliable protection against bacterial pathogens. Recent reports suggest that this era is no longer hypothetical. If current trajectories continue, drug-resistant infections could account for up to 10 million deaths annually by 2050, with staggering economic consequences. To address this escalating threat, researchers are exploring alternative therapeutic strategies that go beyond traditional antibiotics. Among the most promising are antimicrobial peptides (AMPs) and bacteriophage therapy. AMPs are naturally occurring molecules found in animals and other organisms, known for their broad-spectrum activity and rapid bactericidal effects. Their ability to disrupt bacterial membranes through electrostatic and hydrophobic interactions makes them less susceptible to resistance mechanisms that target conventional antibiotics. Bacteriophages - viruses that specifically infect and lyse bacteria - offer a complementary approach. Phage therapy is highly targeted, capable of eliminating specific bacterial strains while sparing beneficial microbiota. Phage’s can also evolve alongside bacterial populations, potentially outpacing resistance development. In veterinary medicine, phage-based treatments have shown promise in managing infections in poultry, swine, cattle, and companion animals, particularly where antibiotic options are limited or ineffective. The combined use of AMPs and bacteriophages represents a novel and potentially synergistic strategy for tackling AMR. By leveraging distinct mechanisms of action and delivery profiles, these agents may enhance therapeutic efficacy, reduce resistance selection pressure, and improve outcomes across a range of veterinary applications. This chapter explores the pharmacological and pharmacokinetic challenges associated with delivering such combination therapies, with a focus on optimizing their use in the fight against antimicrobial resistance.

Introduction
A microorganism or microbe is a tiny living thing that can exist as a single cell or in groups of cells. People have suspected the existence of these unseen microbes since ancient times. These single-celled creatures have caused serious infections that often led to deaths and illness. These microorganisms can spread quickly and cause big outbreaks of disease. In 1928, Alexander Fleming discovered the first antibiotic, penicillin. This discovery started the development of one of the most important groups of medicines in medical history. In the next three decades, many different types of antimicrobial drugs were developed. In his Nobel Prize speech, Fleming warned that using penicillin too much might one day lead to bacteria becoming resistant to it, which would be a major problem. Antimicrobial resistance (AMR) is one of the biggest public health challenges today. Many of the microbes that cause diseases, like bacteria, viruses, and protozoa, no longer respond to common antimicrobial drugs such as antibiotics, antivirals, and antiprotozoals. Antimicrobial resistance is when a microbe becomes able to survive and grow even when treated with medications that used to work on it. Antibiotic resistance is a type of AMR, but it only applies to bacteria becoming resistant to antibiotics. Resistant microbes are harder to treat, and doctors may need to use other medicines or higher doses. These options can be more expensive and have more side effects. Microbes that resist multiple antimicrobials are called multidrug resistant (MDR). Those that are resistant to almost all drugs are sometimes called ‘superbugs’. Antimicrobial prophylaxis is used by doctors to prevent infections, but it should only be used when it’s really needed to avoid unnecessary costs, side effects, and the development of resistance. Antimicrobial prophylaxis can be used to prevent a first infection or to stop an infection from coming back or reactivating.

Introduction
Antimicrobial resistance (AMR) is an escalating global concern, rendering many once-effective antimicrobials useless and threatening modern medicine’s foundations [1]. RNA-based therapies offer precision, programmability, and modularity—tailoring interventions directly to microbial genetic machinery [2, 3].
Main RNA-based modalities include
• Antisense Oligonucleotides (ASOs): Short synthetic single-stranded RNAs that bind complementary mRNA in bacteria to inhibit translation or induce RNase H–mediated degradation [15].
• RNA Interference (RNAi): Though classically applied to eukaryotes, siRNAs or crRNAs delivered via nanoparticles (also termed “nanoantibiotics”) can silence microbial resistance or virulence genes while the carrier materials physically damage microbial membranes— enhancing lethality [3, 4,5].
• CRISPR-Cas Systems: Adapted as antimicrobials, CRISPR-Cas tools can precisely target and cleave resistance genes in pathogens via conjugative plasmids or phages [6].
• Ribozymes / External Guide Sequences (EGSs): Engineered noncoding RNAs that harness RNase P or ribozyme activity to degrade specific bacterial mRNAs [16].
Key strengths
• Target specificity—can silence essential microbial or resistance genes while sparing beneficial microbiota.
• Rapid design and adaptability—once delivery systems are in place, targeting new genes requires sequence change alone.
• Synergy potential—combining gene silencing with antibiotics or physical antimicrobial actions increases efficacy.

Introduction
Antimicrobial resistance (AMR) has emerged as a critical global health threat, diminishing the effectiveness of antibiotics against bacterial infections. Conventional strategies to counter AMR—including antibiotic stewardship programs and the development of new drugs—are often slow, expensive, and labor intensive. However, artificial intelligence (AI) and machine learning (ML) present ground breaking alternatives to address this challenge. By leveraging advanced computational techniques, AI can significantly speed up the discovery of novel antibiotics, enabling researchers to identify promising drug candidates more efficiently than traditional methods. Additionally, ML algorithms enhance treatment optimization by analyzing patient data to recommend personalized antibiotic regimens, reducing misuse and resistance risks. AI also strengthens surveillance systems by processing vast datasets— such as genomic sequences and electronic health records—to detect emerging resistance patterns in real time. These capabilities allow for proactive interventions, helping healthcare providers and policymakers stay ahead of AMR outbreaks. Together, AI and ML offer a transformative approach to mitigating AMR, combining speed, precision, and scalability to combat one of the most pressing medical challenges of our time.
AI in Antibiotic Discovery
One of the most promising applications of AI in AMR mitigation is in antibiotic discovery. Traditional drug development is costly and time-consuming, often taking over a decade [1]. Machine learning models can analyse vast datasets of chemical compounds to predict their antibacterial properties. For example, researchers at MIT used deep learning to identify halicin, a novel antibiotic effective against drug-resistant bacteria. AI-driven platforms can also repurpose existing drugs, reducing the time needed for clinical trials [2].
Fig. 1: AI cyclic interface in antibiotic discovery
Predictive Analytics for Resistance Patterns AI-powered predictive analytics enables early detection of antimicrobial resistance (AMR) patterns by processing clinical, genomic, and epidemiological data. Machine learning models analyse electronic health records (EHRs) [3] and bacterial genome sequences to identify emerging resistance threats in real time. These predictive insights allow hospitals to take proactive measures— such as optimizing antibiotic prescriptions—before resistant strains spread. Beyond clinical settings [4], AI models assist public health agencies in forecasting outbreaks and strategically deploying resources. By integrating large-scale datasets, these systems enhance surveillance, enabling faster, datadriven decisions to curb AMR progression. This approach not only improves patient outcomes but also supports global efforts in combating antibiotic resistance through smarter, pre-emptive interventions [5].

Our animal companions are our family members. We want the best for them and want them to be healthy and happy. However, just as it is with everyone else, our companion animals can also fall ill and suffer from emotions such as grief, fear, and anxiety. And while we follow all expert medical advice, sometimes we may wish for something more – something that will make life easier for them as well as us. This is where the concept of energy healing for animals comes in – to comfort and support our animal companions. With joy, we watch them relax with a sigh; we see our nervous dogs calm down, and those recovering from an acute illness get back on their paws in no time. Energy healing for animals involves a holistic approach to ensure the physical, emotional, and spiritual well-being of our animal friends. It is based on the fundamental concept that just like us, our animal companions too have a subtle energy layer, and they too have vital life-force energies or Prana or Qi. And just like us, they, too, have chakras and meridians through which the Qi flows. Energy healing is a set of powerful techniques practiced to calm and restore the balance of the body. This system is largely based on the removal of energetic blocks and helps restore the body’s energy levels. It is crucial for those living with companion animals to understand the importance of energy healing for their animal companions, as it encompasses a broad range of alternative and complementary therapies designed to support the natural healing process of animals. Here are some proven, popular, non-invasive energy healing techniques that bring relief and comfort to companion animals.
1. Animal Reiki: The word Reiki means “mystical energy.” The system of Reiki for healing was revealed by Japanese Buddhist practitioner Mikao Usui in the early 1900s. And while it was initially meant for humans, practitioners soon discovered that animals responded much more swiftly and effectively to this gentle, non-invasive energy work.
2. EFT Tapping: This involves tapping on specific points on the body to free up emotional blocks. EFT Tapping for animals brings powerful transformations when an animal is struggling with emotional distress, such as grief over the loss of a loved human or animal.
3. Scalar Wave Healing: Scalar Wave was discovered in the 1900s by James Maxwell and later Nicolas Tesla. Scalar Wave harnesses the healing power of high vibrational frequencies meeting to create a standing wave, and practitioners use this to bring about healing at a cellular level.
4. Shamanic Healing: In this ancient technique, practitioners work with the elements of nature, such as plants, trees, and stones, as well as beings in other dimensions, to bring about healing. Shamanic healing can reach beyond space and time and has been very effective in releasing old trauma or emotions that are often hidden beneath layers of survival mechanisms.
5. Healing Mantra: Ayurveda, the Indian system of medicine, advocates about different types of Chikitsa. Daivavyapashraya Chikitsa is one of the treatment approaches concerned with Spiritual way of treatment. It includes so many approaches, amongst all Mantra Chikitsa is described in Ayurveda at various places as a potent approach. It is discussed for both the healthy and unhealthy conditions. Mantra comes from Sanskrit word which means sacred message or text, spell. The word Mantra is derived from Man+Tra, man—mananaat---just by chanting and tra—trayate---- we can protect ourselves. Means, just by chanting one can save himself in the universe. i.e. it is saved from onset of disturbances. Mantras are the words loaded with power and sounds capable of penetrating our body into deep levels. Mantra chikitsa is the ancient science originated from Vedas, this is a parallel science to Ayurveda also called alternative medicine system.Mantra Chikitsa is one among the Daivavyapashraya Chikitsa highlights the importance of concept of Mantra. In Atharva Veda and Kaushikasutra, the two most ancient and authentic sources of Daivavyapashraya. Mantra Chikitsa is mainly used for both preventive and curative aspect. It is also used for the enhancement of the Gunas of Aushadhi. Effect of Mantra is described as Prabhavajanya action. Prabhava means the specific and characteristic action of substances, it is called as Acintya. Mantra Chikitsa cure the Karmaja Vyadhi and Agantuja Vyadhi. In the Vedic period, Daivavyapashraya Chikitsa was followed in various rituals.