eChapters

Microbial Resistance Mechanism

Huge use of antibiotics in nosocomical environment has lead to the occurrence of multidrug resistance mechanism by microorganism against particular antibiotics (Munita et al., 2016; Zhao et al., 2020). Main operation includes chemical modification, efflux pump through passivation, modification of drug targeting gene and systemic elimination of antibiotics as many of them can form biofilm (Rajput et al., 2018) which can show extreme resistance. Chemical and enzymatic mechanism can include inactivation, activity loss, degradation and derivatizaton of antibiotics chemical group (Liu et al., 2019). Best idea may include production of enzymes or they can also expel antibiotic to efflux pump. Antibiotics drug efflux resistance can be accomplished by drug efflux pump playing an important role in microbial resistance. A different type of efflux pump system has been identified that include lipophilic and hydrophilic efflux system targeting the drug at different chemical properties (Wasaznik et al., 2009; Kumar et al., 2012). Another strategy adopting in resistance mechanism is modification of drug targeting gene. This mechanism makes the changes in drug to lose its target through drug targeting gene modification. Another important resistance mechanism is effectiveness of antibiotics by interfering with the target site. Therefore, bacteria has evolved different mechanism that include target site protection. A bactericidal role played by beta lactum antibiotics in inhibition of mucopeptide synthase and bacterial penicillin binding protein (PBP) in cell wall transpeptidation reaction that prevents the formation of complete call wall and hence dies (Sauvage et al., 2016). Bacteria also developed its own strategies to cope up with the environmental stress that can also include human body. In course of gaining the advantage bacteria needs to compete for nutrients and to keep away from the molecules produced by other competing organism (Zhao et al., 2019). Recently researchers have found the importance of biofilm resistance in bacteria. Bacterial biofilm resistance produce by complex and systematic drug resistance mechanism.

Introduction

Antibiotic-resistant bacteria are a major cause of health care-associated infections around the world, and resistance has also emerged in infections in the wider community. Infections caused by multi resistant organisms significantly increase morbidity, mortality, and health care costs. Molecular analyses have revealed that widespread multi resistance has commonly been achieved by the acquisition of preexisting determinants followed by amplification in response to selection. The capture, accumulation, and dissemination of resistance genes are largely due to the actions of mobile genetic elements (MGE), a term used to refer to elements that promote intracellular DNA mobility (e.g., from the chromosome to a plasmid or between plasmids) as well as those that enable intercellular DNA mobility.

Insertion sequences (IS) and transposons (Tn) are discrete DNA segments that areable to move themselves (and associated resistance genes) almost randomly to newlocations in the same or different DNA molecules within a single cell. Other elements, such as integrons (In), use site-specific recombination to move resistance genes between defined sites. As these types of MGE are often present in multiple copies indifferent locations in a genome, they can also facilitate homologous recombination(exchange of sequences between identical or related segments). Intercellular mechanisms of genetic exchange include conjugation/mobilization (mediated by plasmidsand integrative conjugative elements [ICE]), transduction (mediated by bacteriophages), and transformation (uptake of extracellular DNA). Interactions between thevarious types of MGE underpin the rapid evolution of diverse multi resistant pathogens in the face of antimicrobial chemotherapy. Primarily the most important and/ or topical elements in Gram-negative and Gram-positive bacterial species of particular concern clinically, namely, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (the so-called ESKAPE group) (Rice LB., 2008) as well as Escherichia coli (giving the ESKAPEE group) (Llaca-Díaz J.M. et al.,2012); nonetheless, many of the MGE types described are of course broadly relevant to many other bacterial taxa.

Introduction
Antimicrobial resistance (AMR) poses an escalating threat to global health, eroding the efficacy of antibiotics and complicating the management of bacterial infections. The proliferation of resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum betalactamase (ESBL)-producing Enterobacteriaceae, and multidrug-resistant Mycobacterium tuberculosis, has driven significant increases in morbidity, mortality, and healthcare costs. The ability to detect AMR accurately and promptly is paramount for guiding clinicians in selecting effective therapies, implementing targeted infection control measures, and informing public health strategies to curb the spread of resistant organisms. Conventional methods, rooted in phenotypic assessments, have served as the cornerstone of AMR detection in clinical microbiology laboratories for decades. These techniques evaluate bacterial growth under controlled exposure to antibiotics, offering direct evidence of resistance or susceptibility that molecular approaches, which focus on genetic markers, may miss due to silent mutations, complex regulatory mechanisms, or novel resistance pathways. This chapter provides an exhaustive examination of conventional AMR detection methods, encompassing disk diffusion, broth and agar dilution, gradient diffusion, and automated susceptibility testing systems. These approaches, refined through decades of clinical and research application, remain indispensable for their reliability, cost-effectiveness, and adaptability across diverse settings, from well-resourced tertiary hospitals to laboratories in low-income regions. By exploring their principles, procedures, applications, and limitations, we aim to underscore their enduring significance amidst the rise of rapid molecular diagnostics. The discussion also addresses specialized tests for detecting specific resistance mechanisms, such as beta-lactamase production, inducible clindamycin resistance, and carbapenem’s activity, which are critical for tailoring antimicrobial therapy. Through a critical lens, this chapter evaluates the strengths and challenges of these methods, offering insights into their role in addressing the global AMR crisis, their integration with emerging technologies, and their continued relevance in both routine diagnostics and epidemiological surveillance. The value of conventional methods lies in their ability to translate laboratory findings into actionable clinical decisions. Unlike genotypic methods, which detect resistance genes but may not predict phenotypic behaviour, these techniques assess how bacteria respond to antibiotics under conditions mimicking in vivo environments, aligning closely with therapeutic outcomes. As resistance patterns grow increasingly complex, driven by mechanisms like carbapenem’s and efflux pumps, conventional methods provide a practical foundation for diagnostics, particularly in resource-limited settings where advanced molecular tools are often inaccessible. Their role in global AMR surveillance, such as through the World Health Organization’s Global Antimicrobial Resistance Surveillance System (GLASS), further underscores their importance in tracking resistance trends and informing policy.

Aetiology
Classification of the causative agent • Ehrlichia ruminantium (formerly Cowdria ruminantium) Order Rickettsiales, Family Anaplasmataceae
• Small, Gram negative, pleomorphic coccus, and obligate intracellular parasite.
• Strains of E. ruminantium are very diverse and vary in virulence: while some strains are highly virulent, others appear to be less-pathogenic.
• E. ruminantium has a high level of genomic plasticity. Several different genotypes can co-exist in a geographical area, and may recombine to form new strains.
• E. ruminantium multiplies in vascular endothelial cells throughout the body to cause severe vascular compromise.
• It usually occurs in clumps of from less than five to several thousand organisms within the cytoplasm of infected capillary endothelial cells, and can be detected in brain smears by light microscopy.
Resistance to Physical and Chemical Action
Temperature
Heat labile and loses its viability within 12–38 hours at room temperature. Infective stabilities can be cryopreserved in DMSO (dimethyl sulphide) or better yet in sucrosepotassium phosphate-glutamate medium (SPG). Infective half-life of thawed stabilate kept on ice is only 20–30 minutes.
pH: Not applicable.
Disinfectants: Not applicable.
Survival:

Introduction
Antibiotic-resistant E. coli develops as a result of the heavy use of antibiotics in the production of food animals, which is then found in the meat from those animals. There have been reports of a number of antimicrobial resistant E. coli infections linked to the ingestion of tainted milk and chevon. As a result, the existence of antibiotic resistant E. coli is a significant and expanding global public health risk. Escherichia coli of animal origin has also been seen to colonise humans, and because it is resistant to many conventional antibiotics, it can cause serious illnesses for which there are few effective treatment choices. Due to its ubiquitous presence in the environment, E. coli has traditionally been recognised as the main vehicle for the transmission of various antibiotic resistance genes and vectors.Extended-spectrum beta-lactamases (ESBLs), which can make the bacteria resistant to some frequently used antimicrobial treatments, are tiny proteins (enzymes) that some strains of E. coli have been shown to manufacture under favourable conditions. A major issue around the world is the emergence of different E. coli strains that produce ESBL in foods that come from animals that are raised for food. The ESBL enzymes TEM, SHV, and CTX-M from Group A have been widely reported to be generated by E. coli and have been shown to hydrolyze ampicillin, carbenicillin, oxacillin, and an extended spectrum of cephalosporins, including ceftazidime and cefotaxime.
Extended beta spectrum lactamase producing E. coli
The occurrence of antimicrobial resistance and the presence of corresponding resistance genes in the environment is an ancient phenomenon. This is largely due to the fact that many of today’s antimicrobial agents are derived from natural precursors produced by soil bacteria such as Streptomyces. These natural compounds likely evolved to mediate microbial competition for

Introduction
Antimicrobial resistance (AMR) is a global concern that poses a significant threat to contemporary healthcare systems, potentially hindering the management and treatment of various diseases. Microorganisms can act as reservoirs for AMR across various ecological niches; thus, a “one health” proposal is essential for coordinating a multisectoral strategy aimed at investigating and tackling this alarming issue. This method seems to be an effective strategy for addressing and alleviating the challenges posed by AMR; however, it demands the collaborative efforts and assets that are consistently and efficiently executed by health practitioners. Horses have been pivotal in human history; they have served in wars, provided transportation, and even aided in mining operations. In contemporary society, horses are significant as sport animals and in therapeutic settings involving animals. Given these close interactions between humans and equines, it becomes essential to effectively identify infectious diseases and antimicrobial resistance (AMR) impacting both species, particularly in instances of highly contagious diseases. Resistant bacteria represent a significant threat to the health of both equines and humans. Horses may obtain resistant bacteria through several avenues, such as interaction with other animals, exposure to contaminated materials, or to antibiotic uses. The responsible utilization of antibiotics and the implementation of antimicrobial stewardship programs are essential in reducing the transmission of antimicrobial resistance (AMR) within equine populations. A variety of zoonotic pathogens that exhibit resistance to antibiotics has been identified in equines. This includes Extended-Spectrum Beta-Lactamases (ESBL) which produces E. coli, Methicillin-Resistant Staphylococcus Aureus (MRSA), and Multidrug-Resistant (MDR) Salmonella. Horses can develop AMR through various channels like:

Introduction 
The discovery and introduction of antimicrobial agents to clinical medicine was one of the greatest medical triumphs of the 20th century that revolutionized the treatment of bacterial infections. However, the gradual emergence of populations of antimicrobial resistant pathogenic bacteria, resulting from use, misuse and abuse of antimicrobials has today become a major global health concern. Antibacterial drugs have revolutionized our ability to control bacterial disease, and their clinical availability has led to dramatic decreases in morbidity and mortality. (Walsh and Wright, 2005). As such, these therapeutics underpin modern medicine. Despite the integral role of antibiotics in sustaining our modern lifestyle, they are undervalued in both cost and significance by society. Over the past century, their use has provided strong selective pressure on microorganisms, leading to preferential survival and spread of those harbouring antibiotic resistance mechanisms. Multidrug resistance is now commonplace amongst bacterial pathogens with antibiotic resistance now affecting all antibiotic classes. (Coates et al, 2011). This is particularly worrisome in the case of Gram-negative bacteria (e.g. Pseudomonas aeruginosa and Acinetobacter baumannii) for which treatment options are already limited. The ‘broken’ economics of antibacterial research and development is often quoted as the main reason for the lack of new therapies but the truth is that it is hard to discover new antibacterial drugs, and the science is not sufficiently advanced to allow discovery of efficient and effective drugs. This has led to fears of a ‘post-antibiotic era’ as it has been estimated that 5–20 novel antibacterial drugs need to enter clinical development in order to effectively contend with the current resistance problem. However, given the attrition rate within the existing drug discovery model, at least 200 discovery programmes would be needed in order to achieve this outcome. Hence, new approaches to antibiotic discovery are needed. The antibiotic pipeline The antibiotic pipeline is not what it once was.4 Pharmaceutical companies were once the main provider of novel antibiotic molecules but they largely withdrew in the late 1990s because of the lack of success and low financial returns in bringing new antibacterial drugs to the market.5 The environment of discovering and developing new antibiotics was quite different during the so-called ‘golden era’ of drug discovery. Antibiotics worked remarkably well because resistance was low and physicians had access to a variety of efficacious antibiotics. Antibiotic research and development programmes were inclined to focus on improved pharmacology to achieve less frequent dosing e.g. once a day, rather than innovative new antibiotics. Natural product screening strategies tended to result in rediscovery of compounds rather than finding new ones. There was also no need to consider those natural products with undesirable properties such as toxicity. Today, only a few large companies such as GlaxoSmithKline, Novartis, Merck and Roche are still actively engaged in antibiotic R&D, with many of the original antibiotic provide.The natural world remains the largest source of novel drug scaffolds making this a viable option in the search for new antibiotic compounds. Advances in bacterial culture techniques, molecular biology and metagenomics will make natural product drug discovery easier and more costeffective, obviating these limiting factors. Screening procedures must include whole-bacterial cell assays, addressing the issue of bacterial permeability and efflux early in the discovery process (Shore and Coukell, 2016). Additionally, the generation of training schemes by, and with, pharmaceutical companies that cover all aspects of the pipeline and include natural product drug discovery, are essential and will ensure that expertise is passed on to future researchers. Investment should also be made into the study of previously characterized lead compounds that did not reach the clinic, so called old leads. The reasons that led to these compounds being dropped from further development vary, ranging from financial issues to trial design, dosing problems and toxicity. It may be that there is now sufficiently improved technology and expertise to develop these as safe and efficacious antibacterials. The revival of interest in old leads could also provide an additional source of novel antimicrobials. A freely accessible database of antibiotics that were never developed has recently been launched, Antibiotic with the aim to reduce unnecessary duplication of Pharmaceutical agents such as nanospheres, liposomes, and immunoglobulins for example have been developed which can alter the pharmacodynamics of a compound, act as carriers for sustained or controlled drug release, and for immunization therapy.

Introduction
Antimicrobial resistance (AMR) is a mounting global crisis that threatens public health, food security, and development. The rapid spread of resistant pathogens has rendered many conventional antibiotics ineffective, leading to longer illnesses, increased mortality, and escalating healthcare costs(1)(2). The World Health Organization characterizes AMR as a top-ten global health threat, driven by overuse, misuse, and inadequate dosing of antibiotics. It already kills 700,000 people a year and is expected to kill 10 million people a year by 2050 if nothing is done about it(3). After penicillin was introduced to the market in 1941, the first signs of resistance appeared in staphylococci, streptococci, and gonococci. By 1942, Staphylococcus aureus, which was penicillin-resistant, emerged(4). Drug resistance must be effectively addressed for a few reasons, including public health, economic considerations, and the long-term viability of medicine. Maintaining the effectiveness of existing treatments for infectious diseases is an important objective(5). NDDS technologies have emerged as powerful tools to enhance the delivery, bioavailability, and targeting of antimicrobial agents, potentially reviving older antibiotics, and maximizing the efficacy of novel compounds(6). Parallelly, AI has found impactful applications in biomedical data analysis, drug discovery, and the rational design of therapies by processing complex datasets, predicting resistance patterns, and guiding the creation of new molecules. The integration of AI with NDDS marks a paradigm shift to optimizes delivery systems, guides individualized treatment plans, and advances the field towards precision medicine for infectious diseases (7). This chapter surveys the convergence of these technologies, exploring how AIenhanced NDDS platforms are reshaping the response to AMR. Additionally, it examines diverse AI models and algorithms employed in the prediction, optimisation, and management of drug resistance, enhanced by real-time case studies for thorough comprehension(fig1.).

Introduction
The discovery of antibiotics and their subsequent use in combating infectious diseaseswas amedical breakthroughin the 20th century, as it completely changed the treatment approach to infections in general and bacterial infections in particular. In 1928, Alexander Fleming discovered Penicillin that started the started the so-called “golden age of antibiotic”. However, later in course of time the underuse, overuse and misuse of antibiotics in medical and veterinary practice led toemergence of drug-resistant pathogens resulting in phenomenon called antimicrobial resistance (AMR). In last few decades AMR has evolved silently and now threatening the human and animal health and has acquired the potential to be a next pandemic. AMR develops in a microorganism (e.g., bacteria, viruses, fungi, parasites) when it accumulates genetic changes over time and fails to respond to antibiotic(s) leading to severe illness and mortality due to infection. Although, AMR is an evolutionary event occurring naturally in microbes, but inappropriate use of antibiotics in humans and animal medicine act as key driver to its spread. Global antibiotic consumption increased between 2016 and 2023, with total consumption rising by 16.3% to 34.3 billion defined daily doses (DDDs) in reporting countries and a projected 20.9% increase when extrapolated to nonreporting countries. World Health Organization (WHO) and other authorities have called for coordinated action to address antimicrobial resistance, a threat looming large on horizon. In 2021, there were an estimated 1.14 million deaths attributed directly to Antimicrobial Resistance (AMR), with globally another 4.71 million deaths associated with AMR infections. This dataindicates a significant global health burden, with prophecy that AMR deaths could increase dangerously by 2050 if current trends continue. Global Action Plan (GAP) of the WHO highlights the importance of “One Health approach” calling for the joint action in human health, food production, animals and environmental sectors, to achieve better results. In the year 2015, the WHO initiated the Global Antimicrobial Resistance and Use Surveillance System (GLASS)to collect, analyze and share AMR data received from all countries. The Global Action Plan on AMR lists five strategic objectives to contain AMR viz., 1. optimizing the use of antimicrobials, 2. preventing infections (including the use of vaccines), 3. strengthening surveillance and research, 4. improving awareness and understanding of AMR, and 5. investing in new medical products. Vaccines stimulate the body’s immune system to recognize and attack specific pathogens and thus can prevent AMR through several ways viz., 1. reduce the incidence of infections leading to reduction in morbidity and mortality, 2. vaccines can prevent secondary bacterial infections e.g. Streptococcus pneumoniae after an initial infection with influenza, 3. produce herd immunity, 4. Prevention of infections resulting in decrease in use of antibiotics that reduces development of AMR. Immunotherapeutics can both combat and be complicated by Antimicrobial Resistance (AMR). Other immunotherapies antibodies, and immune-boosting agents can directly fight AMR by preventing infections and reducing the need for antibiotics.

Introduction
Antimicrobial resistance (AMR) constitutes a profound global health crisis, jeopardizing the efficacy of antibiotics and posing a severe threat to the foundation of modern medical practice. The rise of multidrug-resistant (MDR) pathogens, which exhibit resistance to multiple classes of antibiotics, has significantly escalated the global burden of infectious diseases, complicating treatment protocols and increasing morbidity and mortality rates. According to the World Health Organization (WHO), AMR could lead to 10 million deaths annually by 2050 if current trends continue, accompanied by economic losses projected to reach trillions of dollars due to prolonged hospitalizations, increased healthcare costs, and reduced productivity. The traditional antibiotic development pipeline has stagnated, hampered by scientific complexities, high financial costs, and stringent regulatory frameworks, resulting in a critical shortage of novel antimicrobial agents. This necessitates the exploration of innovative strategies to combat AMR and preserve the utility of existing antibiotics. Among these strategies, Crispr-Cas (Clustered Regularly Interspaced Short Palindromic Repeats and Crispr-associated proteins) systems have emerged as a groundbreaking gene-editing platform with transformative potential for addressing AMR. Initially identified as a bacterial adaptive immune mechanism, Crispr-Cas has been repurposed to enable precise targeting of genetic elements, offering novel therapeutic, diagnostic, and environmental solutions. This chapter provides a comprehensive analysis of Crispr-Cas systems in the context of AMR, exploring their molecular mechanisms, diverse applications, current limitations, and future prospects across clinical, agricultural, and environmental domains. By leveraging the precision and programmability of Crispr-Cas, researchers aim to develop targeted interventions that mitigate the spread of resistance while minimizing collateral damage to beneficial microbial communities.

Introduction
AMR is a critical global problem that affects human, environmental, and animal health. AMR is a complex problem; it is necessary to look at it from different disciplines to frame it within the One Health approach [Shrestha,2018].The World Health Organization (WHO) has identified AMR as a top ten global public health threat.Globally, there were an estimated 4.95 million deaths associated with bacterial AMR in 2019, including 1.27 million deaths attributable to bacterial AMR [O’Neill, J. (2016)]. The economic impact is equally alarming. The World Bank projects that AMR could lead to an additional US$ 1 trillion in healthcare costs by 2050, and over US$ 1 trillion in annual gross domestic product (GDP) losses by 2030.The One Health approach is defined as a joint effort of various disciplines that come together to provide solutions for human, animal, and environmental health. AMR is linked to each of these three components due to the irresponsible and excessive use of antimicrobials in various sectors (agriculture, cattle raising, and human medicine). Under the pressure of antimicrobial selection, bacteria acquire resistance genes and mobile genetic elements that can spread to other bacteria of the same or different genus. When bacteria acquire resistance to antimicrobials, they also acquire a greater ability to proliferate in animals, humans, and the natural world. Mismanagement of antimicrobials, inadequate infection control, agricultural debris, contaminants in the environment, and migration of people and animals infected with resistant bacteria facilitate the spread of resistance [Collignon,et.,al,2018]. AMR represents a global public health problem, for which epidemiological surveillance systems have been established, aiming to promote collaborations directed at the well-being of human and ani mal health and the balance of the ecosystem. Several international organizations (The World Organisation for Animal Health [OIE], WHO, and the Food and Agriculture Organization of the United Nations [FAO]) have joined forces to develop a Global Action Plan on Antimicrobial Resistance-WHO. Action taken in this plan included understanding the AMR from surveillance and research. The advisory group established guidelines for AMR surveillance to ensure all countries implement integrated surveillance, which will cover the use and consumption of antimicrobials in the human and animal population. These guide lines will provide a clear understanding of how AMR spreads in different settings and specific areas. It will allow to study the correlation between AMR and antimicrobial use in a different setting (animals, humans, and environment) and to assess the effect of interventions within and between sectors [W.H.O 2015,2017].

Introduction
Animal sector is growing very fast particularly in India as people’s purchasing power is increasing day by day. With increase in income, people’s dietary habit is shifting towards more animal origin products. The use of antibiotics for animal food production is growing very fast and India is the 4th largest country in the world regarding consumption of antibiotics in veterinary and animal husbandry sector. There is urgent need of AMR mitigation strategies to reduce the effect on human and animal health. As per the World Bank AMR can affect the global GDP upto 3.8% by 2050. Most of the countries in the world are very cautious regarding antibiotic residues and rejecting the livestock products which lead to economic loss. Many world agencies/forum such as CodexAMR Guidelines, UN Political Declaration on AMR Guidelines, Global Leaders Group on AMR reiterated judicious use of antibiotics. All-India Network Project on AMR inLivestock and Fisherieswas started in India to reduce the effect of AMR by educational awareness, adoption at field level, surveillance system and diagnosis but it didn’t meet out the desired outcome. Capacity building programmes in the field of AMR by training, reform in curriculum, collaboration from different fields of professionals can mitigate the harmful effect of AMR. According to the Food and Agriculture Organization (FAO), education and training play pivotal roles in translating knowledge into practical implementation, warranting the inclusion of Antimicrobial Use and AMR as integral components in professional education, postgraduate training, and continuing education within the food and agricultural sectors Training Strategies It involve Antimicrobial Stewardship training for healthcare professionals, public awareness campaigns, farmer education, and veterinary training on responsible antimicrobial use. Other critical elements include fostering collaboration through professional networks, building surveillance capacity, utilizing AI-driven tools for better decision-making, and promoting hygiene and infection prevention to reduce infection incidence and the need for antibiotics.
Training for Healthcare Professionals
There is substantial evidence that both healthcare workers and members of the public have knowledge gaps about appropriate use of antibiotics and mechanisms of antibiotic resistance. Surveillance is a prerequisite to estimate the magnitude of the AMR burden and to establish any intervention strategies, such as antimicrobial stewardship. In order to launch successful intervention approaches through cooperative efforts from different stakeholders (e.g., international agencies, human and veterinary medicine sectors, agriculture and animal production industries, and consumers), the existing knowledge gap needs to be addressed first.

Mycotoxins are the secondary metabolites produced by moulds, which grow on food and feedstuffs causing pathological or physiological changes to humans and animals. They are toxic to vertebrates in low concentrations. Symptoms depend on the amount of toxin in the feed, the period for which the infested feed is ingested, the nutritional status of the feed and the susceptibility of the animal species. Toxic effects of chronic consumption of mycotoxins in human are carcinogenicity, hepatotoxicity, oestrogenicity, genotoxicity, nephrotoxicity, immunosuppression, reproductive disorders and dermal irritation (Anfossi et al., 2010). The most extensively studied mycotoxins viz., Aflatoxins, ochratoxins, deoxynivalenol (DON, vomitoxin), T-2 toxin, zearalenone, fumoninsins, mycophenolic acid, cyclopiazonic acid and ergot toxins are produced by the moulds Aspergillus, Fusarium, Pennicillium and Claviceps (Iqbal et al., 2015).

Mycotoxins are toxic secondary metabolites produced by different types of moulds which are present in soil, plant and feed ingredients. Ingestion of toxins will result in reduced growth and production performance due to reduced nutrient utilization, illness or death of animals. Analysing the presence of mycotoxin and its concentration in grain and feeds is necessary to eliminate the adverse health effects of mycotoxins in animals. Estimation of mycotoxin in feed ingredients is a challenging task because the concentration of toxin is at µg/kg or parts-per billion levels. At the same time, analysing inappropriate samples is a waste of resources. Mycotoxins are not evenly distributed in feeds or grains. If the specimen collected for analysis includes contaminated grain, the mycotoxin will be detected. If not, the mycotoxin will not be detected.

Sample collection for mycotoxin analysis

The objective of sample collection is to collect the specimen samples from as many parts of the feed lot as possible. The size of the collected specimen depends on the size of the load received. Sample collecting probes can be used to collect the samples from bags.

Antigen-antibody interaction is very specific one in which an antibody recognizes an antigen through complementarities of shapes on paratope and epitope.  It is like lock and key, as occurs in case of enzyme-substrate reaction. It does not involve covalent linkage rather a spatial complementarity occurs between antigen and antibody. For example, when antibodies, raised against m-amino benzene sulphonate, are tested for their ability to bind with ortho-, meta- and para-isomers of the hapten, the antibodies show highest strength with meta than ortho- isomer.  Antibodies show poor reactivity with para isomer. This is because though chemically all these molecules are same but structurally they are different.

All blood cells arise from a basic cell called the hematopoietic stem cell. Stem cells are undifferentiated embryonic cells.They are self renewing and their population by cell division. Stem cells have the ability to develop into any type of blood cell. The formation of blood cells begins in the embryonic yolk sac during the first week of development. Every mature cell is derived from the same type of stem cell. In contrast to an unipotent cell which differentiates into a single cell type, a hematopoietic stem cell is multipotent or pluripotent. In the mammalian embryo, the blood corpuscles are normally formed in yolk sac, liver, spleen and thymus gland.

The immune system protects the body from harmful substances by recognizing and responding to antigens. Antigens are the protein molecules which are present on bacteria, virus, fungi or some other microorganisms.Some toxins can also be antigens. These antigens are recognized by immune system. The destruction of antigens by producing antibody is called antibody-mediated immune response. As antibodies are present in the body fluids i.e. humors,this type of response is called humoral immune response.

Immunity is defined as the resistance to infection. This is carried out by the process of identification and removal of non-self material. In contrast to this, our body has to maintain immune tolerance to our own cells and tissues and develop the ability to distinguish these self-antigensfrom non-self (foreign) antigens. Tolerance means unresponsiveness of the immune system to an antigen. Immune tolerance is the process by which the immune system does not destroy an antigen. Tolerance can be either natural or induced.

Taxonomy (biological systematics) is the branch of science which deals with classification of units or individuals on the basis of similarities and differences. The classification, nomenclature, and identification are three interrelated components of bacterial taxonomy (Cowan, 1965).

Classification: Classification is the arrangement of bacteria into groups (taxa) based on the similarities of certain characteristics. Presently 11,000 bacterial species is classified. At the current rate of 600 bacterial species / year it is estimated to take 1000 years to classify all the bacteria!

Nomenclature: It is the assignment of specific names to the taxonomic groups following the regulations mentioned in ‘International Code of Nomenclature of Bacteria’ (Euzeby, 1997). International committee on systematic bacteriology (International committee on systematics of prokaryotes, ICSP) standardizes the code. The committee is helped by a number of taxonomic subcommittees on different groups of bacteria. The Code can be amended by the Judicial Commission. The Code contains general considerations, principles, rules and recommendations on the naming of prokaryotes (bacteria) up to the rank of ‘Class’.

Transplantation refers to the implantation of a tissue or organ from one site  to another site in an individual or from one individual to another.It involves implanting of organs or grafting of tissues to repair defects and to stimulate regeneration. Auto-transplantation or autoplasty of the skin, cartilage, bone, muscle, tendon, nerve and fatty tissue is used in plastic and cosmetic surgery. The replacement of a diseased organ by a transplant of a healthy tissue is called transplantation.