eChapters

Introduction

Seed is a living entity (mature ovule) consisting of a tiny plant in embryonic stage along with the stored food protected by an outer layer known as seed coat. Seed is an important biological input in agriculture, which is economically important for successful crop husbandry. Cotyledons serve as the source of nutrients (proteins, carbohydrates, and oils) that not only nurture the plant at the early developmental (seedling) stages of plant but also the vegetarian (heterotroph) organisms. Being one of the important inputs in agriculture, viability of seed needs to be assessed to know the germination percentage of seeds used to raise a crop. Since viability of seeds may deteriorate on storage depending on the storage conditions. Therefore, often it becomes important to test viability/germinability and vigour of seeds before being used for raising a crop or conducting an experiment. In this chapter, we briefly discuss about the different methods which can be used for testing the viability of seeds.

Seed Viability

Seed viability can be defined as the capability of the seed to germinate and produce a normal seedling within a specified period. In other words, seed viability indicates how many seeds in a lot are alive and could develop into plants under appropriate field conditions. It is very important that most of the stored seeds are capable of germinating when sown in a field. They must possess higher viability at the beginning of storage and maintain it over the storage. A seed with high initial viability survives longer in storage; however, the viability deteriorates slowly at first and then rapidly as the storage prolongs. It is important to know the duration of storage after which a considerable decline in viability occurs under given storage conditions so that to take necessary action to revive the seeds. Excessive deterioration in vianility of seeds may lead to loss of the seed/material/ germplasm.

Antibiotics, often referred to as “magic bullets” in the battle against bacteria, stand out as one of the most remarkable medical breakthroughs of the 20th century. Their advent revolutionized the therapeutic landscape, consistently saving millions of lives from bacterial infections (WHO, 2020). Undoubtedly, antibiotics are a blessing to humanity, not merely for their medicinal applications but also for their diverse uses. They have long been employed in various contexts, including animal husbandry and production, serving as preventive measures in numerous underdeveloped and developing nations for decades (Majumder et al., 2020). A range of antimicrobial agents, including antibiotics, antifungals, antivirals, disinfectants, and food preservatives, function to either inhibit microbial growth or eradicate them altogether. Among these, antibiotics, specifically tailored to combat bacterial infections, are the most widely used class of antimicrobials. With their increasing and often improper use, microorganisms have developed antimicrobial resistance (AMR) (Murray et al., 2022).

Antimicrobial resistance is an inevitable evolutionary process observed in all microorganisms, and is driven by genetic mutations aimed at resisting the lethal pressures of selection. Bacteria, adapt to environmental selection pressures by developing resistance to antibacterial drugs, thereby diminishing the efficacy of these treatments (Murray et al., 2022). The widespread use of antibiotics, particularly in developing nations, further flares up the process, leading to significant repercussions such as increased rates of morbidity and mortality (WHO, 2020). The incidence and prevalence of antimicrobial resistant bacterial infections have reached alarming levels in the 21st century, posing a substantial threat to global public health akin to a silent pandemic. Antibiotic resistance knows no borders and can impact individuals of any age or gender, regardless of their location. In its present state, antimicrobial resistance (AMR) stands as one of the foremost threats, not only to global health but also to food security (Murray et al., 2022).

Antimicrobial resistance (AMR) is a mounting global health emergency that threatens the effectiveness of modern medicine and veterinary care. In India, the challenge is compounded by high antibiotic consumption, unregulated access to antimicrobials, and widespread use in agriculture and animal husbandry. The World Health Organization has identified the Eskape pathogens— Enterococcus faecium, Staphylococcus aureus, Klebsiellapneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp, as priority organisms due to their ability to “escape” the effects of antibiotics and cause life-threatening infections. Simultaneously, zoonotic transmission of resistant bacteria from animals to humans is emerging as a critical concern, particularly in regions with close human-animal interfaces like Jammu & Kashmir. The importance of Eskape pathogens to the establishment and promotion of antimicrobial resistance in hospitalized patients was first recognized in a 2008 by Rice. The morbidity and mortality associated with Gram-negative Eskape pathogens is particularly concerning, as new antimicrobial agentsthose with activity against multidrug-resistant and pan-resistant Gram-negative strainshave not emerged as quickly as needed. Consequently, nosocomial infections continue to pose a serious threat to patient health, especially among critically ill inpatients and those undergoing invasive procedures or requiring the placement of medical devices. Eskape pathogens are well known for their intricate resistance mechanisms, often leaving clinicians with limited therapeutic options. Due to their significant role in driving antimicrobial resistance within hospital settings, consistent and systematic monitoring of their resistance profiles is crucial for guiding effective infection control and therapeutic strategies.This also serves as a critical indicator of regional resistance trends among hospitalized populations. In animal sector, the wastewater of livestock slaughterhouses, animal products (raw or processed) have been considered a source of multidrugresistant bacteria with clinical implications as well as their dissemination into the environment and entry into human food chain.Bacteria from the livestock can act as opportunistic pathogens and carry resistance genes that are important for both veterinary and human health. Since many antibiotics are used in both human and animal health fields, the resistant bacteria enter the environmentespecially through wastewater treatment plants affected by slaughterhouse wasteposing risks to public health. Among the various sources, the water used during poultry slaughtering often contains multidrug-resistant bacteria and can expose slaughterhouse workers to infection. To reduce these risks, it’s important to develop strategies that limit bacterial release into the water systems and prevent their spread to people and the environment. The development of AMR has been attributed to several factors comprising of microbial mutations rendering the antibiotics ineffective, human interference such as over use and over-prescription of antimicrobials, agricultural and commercial application of antimicrobials in the animal sector, and human behavioural factors (Vijayalaxmi et al., 2021). An expected annual rise of antimicrobial resistance (AMR) by 5–10 % annually has been predicted by the Indian Council of Medical Research (ICMR) Annual Report 2021 due to wide spread abusive use of broad-spectrum antibiotics (ICMR Annual Report 2021). Twelve families of priority drug-resistant bacteria (critical, high and medium) posing great threat to human health in terms of resistance to selected antimicrobials have been identified in priority pathogen list (PPL) of Global Action Plan, World Health Organisation (WHO) to stimulate the research towards the development of new antimicrobials against a particular drug-resistance (WHO,2017). From the Indian perspective, AMR is a grave concern as the Indian population is the highest consumer of antibiotics in the world (10.7 units per person). The poor public health systems, hospital infections, high rate of infectious diseases, easy availability of inexpensive

Introduction
Antimicrobial resistance (AMR) is regarded as a silent pandemic that is responsible for causing the majorityof deaths every year and has become a major healthcare challenge and a significant public health issue. It has been reported that AMR alone has caused more fatalities than road accidents and cancer. It is among the top ten global health threats and has been recognized as a part of the multisector One Health approach. It has been predicted that by the year 2050, the burden of AMR will decrease the gross domestic product (GDP) by 2 to 3.5%, causing a loss of USD100 trillion to the world, with the annual death rate reaching 10 million. India faces one of the world’s highest antimicrobial resistance (AMR) rates, driven by high antibiotic consumption in humans, widespread non-prescription use, and unregulated application in livestock, aquaculture, and agriculture. Surveillance data show alarming resistance in major pathogens E. coli and Klebsiella,which now exhibit very low susceptibility to key antibiotics such as cefotaxime, ciprofloxacin, and carbapenems. Factors exacerbating the burden include inadequate infection prevention, limited laboratory capacity, poor enforcement of regulations, environmental contamination from pharmaceutical and hospital waste, and low public awareness. The combined impact threatens public health, food safety, and the economy. In general terms, AMR is defined as the ability of the microorganisms to withstand the action of an antimicrobial agent,i.e. Antibacterial agents, antifungal agents, potentially toxic metals, and disinfectants. AMR is known to be a natural process that occurs over time due to genetic changes in the pathogens under selective pressure, where a pathogen undergoes mutations and is often linked to indiscriminate use of antimicrobial agents.
Indefinite and improper use of antimicrobial agentshas been a major factor in the emergence of AMR. AMR affects both animals and humans alike, and resistant pathogens pose a challenge in treating infections. One of the crucial factors responsible for AMR is theenvironment, which is regarded as both a vehicle for spreading AMR microbes as well is a culprit of AMR pollutants, which severely impact the ecosystems. AMR is a multifaceted problem and to control it effectively, meticulous measures have been implemented for monitoring and surveillance of AMR in clinical settings, in both human and veterinary fields. However, the environmental surveillance dealing with the environmental AMR has yet to be established. The implementation of comprehensive monitoring of AMR in environment will vastly improve our understanding of the various dissemination routes and propagation of the resistant microbes in environment and their role in spreading AMR. In this chapter, we will discuss the environmental spread of AMR, drivers of AMR in the environment, factors influencing AMR, challenges faced, measures to tackle AMR, and future trends in curbing the burden of AMR.

Introduction
Haemoprotozoan diseases are highly prevalent in tropical and sub-tropical countries owing to the ubiquitous distribution of ticks and blood-sucking flies which are natural vectors for the pathogens. In India, theileriosis, babesiosis and trypanosomosis are major haemoprotozoan diseases and cause substantial economic losses to the livestock industry. Though vaccination of the susceptible stock by attenuated schizont vaccine is available for the control of tropical theileriosis in cattle, chemotherapy is the mainstay for the control of haemoprotozoan diseases. However, the limited available antihaemoprotozoan drugs is being depleted by a combination of two factors viz. emergence of drug resistance and the failure to replace old drugs (de Koning, 2017). Drug resistance against parasites is one of the emerging problems affecting veterinary health sector. Since last few decades, development of drug resistance in haemoprotozoan parasites to several drugs has been reported (Tuvshintulga et al., 2019; Ali et al., 2022). Though, understanding of drug resistance in parasitic protozoa is progressing steadily but possibly not as rapidly as parasites are becoming resistant to drugs. The genetic changes in the target sites, the reduced uptake and increased efflux of drugs, and metabolic regulations are the possible mechanism for the cause of drug resistance (Fairlamb et al., 2016). Anti-protozoan drug resistance has been reported in many economically important protozoa to isometamedium, diminazene aceturate, quinapyramine, suramin, melarsomine dihydrochloride, buparvaquone. The resistance initially evolves at genetic level of parasite with genetic traits that allow them to survive exposure to a drug, which is transferred to the subsequent generation thereby potentially increasing the percentage of resistant parasite that can survive subsequent exposure to the chemical. The emergence of drugresistant parasites has serious implications for treating clinical cases, leading to increased morbidity and mortality among the animals and control of the diseases.

Introduction
 Antibiotic therapy is one of the mainapproaches of modern medicine used tofight bacterial diseases worldwide.Antibiotics comprise of any natural, synthetic, or semi-synthetic substances which interfereswith the growth and development of microbes or have killing effect onmicrobes, specifically bacteria. The availability of these antibiotics for treating various bacterial infectious diseases significantly improved the quality of life of humans as well as animals.The period from1930s to 1960s is considered as the ‘golden era’ of antibiotics during whichmost of the antibiotics available today werediscovered. Antibiotics, once known as the magic bullets of modern-day medicine, are now an “endangered species” facing the danger of extinction due to the worldwide emergence of antibiotic resistance (ABR)/antimicrobial resistance (AMR) among microbes. In general, AMR is the capacity of a microbes (bacteria, fungi, and viruses) to resist the growthinhibitory or killing activity of an antimicrobial beyond its normal susceptibility by altering their physiologyor genetic makeup. AMR has emerged as one of the most critical and complicated global public health threat due to its multi-faceted nature.World Health Organization (WHO) has declared AMR as one of the top 10 global public health threats. The emergence of AMR is closely related to the extensive use and misuse of existingantibiotics in the human and animal fields without properguidelines as well as failure to developor discover new antibiotics. AMR leads to a significant health burden worldwide as it is estimated that bacterial AMR alone attributesto 1.14 million deaths globally in the year 2021 and if left unchecked, it may contribute to 10 million deaths annually by 2050.This prediction was recently updated with the data from 2019 and reported that the deaths of 4.95 million people were related to drug-resistant bacterial infections and 1.27 million deaths were directly attributable to AMR.In addition to the health burden, AMR also increases the healthcare costs and imposes significant indirect economic burdens.Increasing reports of treatment failures in patients with infections caused by multi-, extensive-, and pan-drugresistant bacteriahave been documented in literature from different part of the world. Antibiotics once normally used to treat bacterial infections are no longer effective, and it becomes vital to use “reserve” or “last resort” antimicrobials that are often more expensive. Furthermore, WHO has also emphasized that AMR not only makes infections harder to treat but also jeopardizes ancillary medical procedures such as surgeries and cancer treatments. Food may act as a carrier for the transfer of antimicrobialresistant bacteria (AMRB) and antimicrobial resistance genes (ARGs) to humans.Many scientific reports establish a link between the extensive use of antibiotics duringagricultural production and the increase in AMRamong human pathogens, in which food is one of thepossible transmission routes. Antibiotics are regularly added to feed as additives in intensive animal production systems at sub-therapeutic doses to stimulate growth, improve feed efficiency and avoid infections. The extensive use of antibiotics in human treatment, animal therapy and agricultural use as growth promoters are further causes of bacterial resistance to antibiotics. In recent years, the prevalence of AMR among microorganisms isolated from animal source foods (milk, meat, eggs etc) has increased. The increasing demand for quality animal protein has driven intensive farming, leading to increased antimicrobial usage. In the year 2020, global antimicrobial consumption in food-producing animals was estimated around 99,502 tonnes.Antibiotics are commonly used prophylactically infoodproducing animals and it is projected that by 2030 such usewill increase by approximately 67% globally.Despite efforts to reduce antibiotic use, many countries still rely heavily on antimicrobials for growth promotion and disease prevention. The Food and Drug Administration (FDA) has emphasized the need for better monitoring of antimicrobial use in animals. The emergence and spread of AMR in the food chain is considered as a multisectoral issue, because (i) antibiotics are widely used in livestock production systems (cattle, poultry etc), (ii) AMRB and ARGs can easily spread at each stage of the food production chain, and (iii) these AMRB can cause infections in humans.Thus, the emergence of AMR along the food chain is a major

Introduction
The discovery and widespread use of antibiotics in the mid-20th century marked a transformative era in modern medicine, enabling life-saving interventions in surgery, transplantation, and critical care. Diseases once considered fatal became manageable, and the global burden of infectious diseases significantly declined. However, the remarkable success of antibiotics has been increasingly overshadowed by the rapid rise of antimicrobial resistance (AMR), now recognized by the World Health Organization (WHO) as one of the most serious threats to global health, food security, and sustainable development. Resistant infections already contribute to longer hospital stays, increased healthcare costs, and elevated mortality rates. Alarmingly, if current trends continue, AMR-related deaths are projected to exceed those caused by cancer by 2050.A pivotal yet often underestimated factor in the persistence and spread of AMR is the formation of microbial biofilms. Biofilms are highly organized, surface-attached communities of microorganisms embedded in a self-produced extracellular polymeric substance (EPS) composed of proteins, polysaccharides, lipids, and nucleic acids. This matrix not only anchors microbial population but also confers protection against environmental stressors, immune responses, and antimicrobial agents. Bacteria within biofilms can withstand antibiotic concentrations up to 1000 times higher than their planktonic counterparts due to altered metabolic states, enhanced horizontal gene transfer, and activation of resistance mechanisms such as efflux pumps. Biofilms are implicated in over 80% chronic and device-associated infections, including those caused by ESKAPE pathogensAcinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Staphylococcus aureus. These infections are notoriously difficult to treat and often recur, posing significant clinical challenges. Beyond healthcare settings, biofilm formation in livestock and agricultural environmentsexacerbated using antibiotics as growth promoterscontributes to the emergence of resistant strains that can spread to humans via direct contact, environmental contamination, or the food chain.Understanding the multifaceted resistance mechanisms within biofilms is essential for developing effective containment strategies. These include physical exclusion of antibiotics by the EPS matrix, metabolic dormancy, persister cell formation, quorum sensing-mediated coordination, and stress response activation. Moreover, biofilms often consist of multispecies communities, where interspecies interactions further enhance resilience.In response, antibiofilm agents have emerged as a promising frontier in AMR containment. These include natural compounds (e.g., antimicrobial peptides, essential oils), engineered materials (e.g., nanoparticles, surface coatings), quorum sensing inhibitors, efflux pump blockers, and enzymatic disruptors such as dispersin B and DNases. Ecological approaches like probiotics and positive biofilms offer preventive strategies in agriculture and food systems. Importantly, these agents aim to complement antibiotics by enhancing their efficacy rather than replacing them.Despite challenges in scalability, safety, and regulatory approval, antibiofilm strategies represent a paradigm shift in infection control. Their integration into clinical, veterinary, and environmental practicesaligned with the One Health frameworkis essential for preserving antibiotic effectiveness and mitigating the global AMR crisis.

Introduction
Antimicrobial resistance (AMR) has become a major worldwide health issue, requiring the search for natural, safe, and efficient substitutes for synthetic antibiotics. The ancient medical system known as Ayurveda lists a variety of polyherbal compositions having jwaraghna (antipyretic) and krimighna (antimicrobial) qualities. A traditional decoction preparation that is frequently prescribed for microbial infestations (krimi), wound infections, fevers, and skin conditions called Nimbadi Kwatha.Strong herbs that have been separately shown to have antibacterial and immunomodulatory properties, including Nimba (Azadirachta indica), Guduchi (Tinospora cordifolia), Triphala (Haritaki, Bibhitaki, Amalaki), Vasa (Adhatoda vasica), and Katuki (Picrorhiza kurroa), make up Nimbadi Kwatha. Triphala has antimicrobial and antioxidant qualities, Guduchi boosts host immunity and has antibacterial qualities, and Neem provides broad-spectrum antibacterial, antifungal, and antiviral activity. According to experimental studies, giloy extracts are effective against a variety of pathogens, such as bacteria, viruses, and fungi. It has a distinct antimicrobial activity that involves two mechanisms: it enhances phagocytosis, changes cytokine production, and activates macrophages. In light of antimicrobial resistance (AMR), T. cordifolia is a prospective option for the development of plant-based antimicrobials and integrated therapies. Its use is backed by both modern pharmacological research and ethnomedicinal history for infectious disorders and immune health. Nimbadi Kwatha and its derivatives, including Nimbadi Ubatan and soap formulations, have been shown to have antibacterial properties by modern pharmacological research, which also showed a notable inhibition of bacterial and fungal growth in vitro. These results demonstrate the value of Ayurveda in treating infectious diseases and lend credence to its traditional claims. To close the gap between traditional knowledge and contemporary evidence, a thorough analysis of Nimbadi Kwatha’s antibacterial impact is essential. It also identifies the plant’s potential as a natural remedy for drug-resistant infections.

Introduction
Antimicrobial resistance (AMR) has emerged as one of the most alarming public health challenges of the 21st century, threatening the effectiveness of life-saving drugs and the future of modern medicine. This crisis is not limited to healthcare settings; it spans communities, agriculture, and the environment, impacting every facet of society. India, with its large population, high burden of infectious diseases, unregulated access to antibiotics, and considerable pharmaceutical manufacturing industry, stands at the forefront of the global struggle against AMR. The rise of resistant microbes stems from a complex interplay of factors: overuse and misuse of antibiotics in humans and animals, poor infection prevention practices, lack of sanitation, and environmental contamination from antibiotic waste. As a result, common infections are becoming harder to treat, surgical procedures riskier, and healthcare costs are escalating, all leading to increased morbidity and mortality. Tackling AMR requires robust intersectoral collaboration—no single stakeholder can succeed alone. Non-governmental organizations (NGOs), industries, and Corporate Social Responsibility (CSR) initiatives form a critical triad in India’s fight against AMR. NGOs drive grassroots education, advocacy, surveillance, and policy change, often bridging gaps where governmental capacity is limited. The pharmaceutical and healthcare industries, responsible for antibiotic manufacturing, distribution, stewardship, and infection control, play a pivotal role in curbing environmental emissions, supporting responsible use, and promoting the discovery of new treatments. Meanwhile, CSR channels the resources and expertise of corporations towards sustainable, communityfacing projects that promote awareness, improve hygiene, foster stewardship, and drive systemic change.

Different type of mycotoxins commonly present in different feed and fodder crops are produced by mould during cultivation and storage and are specific to certain region according to climatic and environmental conditions. Most of the toxins produced in crops are consumed when fed to animals. Among the mycotoxins, aflatoxin B-1 is present in highest concentration which enters rumen following ingestion of aflatoxin contaminated feed stuffs. In the rumen, AFB-1 is degraded into aflatoxicol and the remaining portion of the aflatoxin is absorbed in the digestive tract by passive diffusion and metabolized in the liver into aflatoxin M-1 (Kuilman et al., 1998). AFM-1 circulates in the blood as a stable compound until excreted in milk, urine and bile. The following are the sources of AFM-1 contamination in milk and milk products and it occurs through two modes of contamination viz., indirect contamination and direct contamination.

Cell mediated immune response performs different functions in protecting the immune system. When antigens are destroyed by cells, without producing antibodies, the immunity is called cell-mediated immunity (CMI) or cellular immunity. In this immunity T cells play a major role. The principal role of cell mediated immunity is to detect and eliminate the cells that have intracellular pathogens. When the antigen remains inside the cell the antibody cannot handle them. The intracellular pathogens are controlled by cell- mediated immunity. CMI is invited by the recognition of antigens by T cells. T cell lymphocytes recognize protein antigens of intracellular microbes that are displayed on the cell surface of infected cells. It is also important for elimination of cells which express foreign MHC molecules. Antigen specific and nonspecific cells can contribute to the cell-mediated immune response. The activities of both specific and non-specific components usually depend on effective local concentration of cytokines.

Metabolomics is the comprehensive qualitative and quantitative study of metabolites present in biological systems under specific physiological or pathological conditions. This chapter introduces the concept of metabolomics and the metabolome and explains their importance in understanding cellular function and phenotype. It traces the development of metabolomics from classical biochemical analysis through chromatography, mass spectrometry, NMR spectroscopy, and modern high-throughput technologies. The chapter discusses applications in medicine, agriculture, biotechnology, pharmaceuticals, and environmental sciences. It also explains the relationship between metabolomics and systems biology, emphasizing the role of metabolites as functional indicators connecting genotype with phenotype and supporting biomarker discovery and biological systems analysis.

Murray (1926) and Pirie (1927) first described Listeria independently. In India, animal listeriosis in sheep was first reported by Mahajan (1936) in Andhra Pradesh.

Robert Koch first isolated Erysipelothrix in 1876 from a mouse he inoculated with putrefying blood. Koch initially named the bacterium “Bacillus of mouse septicemia”. Pasteur and Dumas (1882) first isolated Erysipelothrix from the infected pigs. Friedrich Loffler (1886) first experimentally produced the infection in pigs. Rosenbach (1909) first described human erysipeloid. The nomenclature of the bacterium is changed several times and Erysipelothrix rhusiopathiae was finally accepted by the scientific community in 1966. The name is originated from Greek words such as ‘erysipelas’ (red skin), ‘trix’ (hair), ‘rhusius’ (reddening) and ‘pathus’ (disease).

ENZYMES

Enzymes are the heart of Biochemistry

Protein based catalysts.

Enormously effective catalysts: typically enhance rates by 10⁶ to 10¹² fold.

Operate under mild conditions: 0 - 100 °C (or perhaps even 300+ °C for some bacteria in deep ocean), 20 - 40 °C for most organisms; and low pressures (atmospheric).

Very specific: Generally catalyze reaction for a very restricted group of molecules, sometimes for a single naturally occurring molecule of a single chirality.

V    :    Volt.

V domain    :    The variable region of the polypeptide chains of an immunoglobulin or T-cell receptor is composed of a single N-terminal V domain. Paired V domains form the antigen-binding sites of immunoglobulins and T-cell receptors.

Lucke (1862) first described that the bluish green discolouration of surgical dressing is associated with the presence of small vibrio like organisms. Gessard (1882) first isolated the bacteria as Pseudomonas.

Identification of the etiologic agent of glanders was performed in 1882 by isolating a bacterium from the infected liver and spleen of horse. Since its discovery, the pathogen has been classified as Loefflerella mallei, Pfeifferella mallei, Malleomyces mallei, Actinobacillus mallei, Corynebacterium mallei, Mycobacterium mallei, Pseudomonas mallei, and currently as Burkholdria mallei. The genus Burkholderia was created to accommodate former rRNA group II (Pseudomallei group) Pseudomonas bacteria. It was based on the 16S rRNA sequences, DNA-DNA homology values, cellular lipid and fatty acid composition.

Louis Pasteur (1881) first isolated the bacterium from fowl cholera outbreak and attenuated the bacteria to develop a vaccine for the chicken. Trevisan (1887) coined the generic name ‘Pasteurella’ in honour of Louis Pasteur. Lignieres (1900) proposed the name of the species according to the animals acted as the major hosts such as Pasteurella aviseptica for fowls, P. suiseptica for pigs, P. boviseptica for bovines, P. oviseptica for ovines and P. leptiseptica for rabbits. Rosenbuch and Merchant (1939) proposed the name of single species Pasteurella multocida which is in use till date.

Mannheimia is an exclusive animal pathogen and is associated with ‘shipping fever’ or bovine respiratory disease (BRD) in cattle. Kitt (1885) first described the bacterium as Bacterium bipolare multocidum isolated from shipping fever in cattle. The nomenclature was further changed into Bacillus boviseptica and finally into Pasteurella haemolytica. Based on fermentation capability of arabinose and trehalose, P. haemolytica was subdivided into two biotypes (A and T) and several capsular serotypes. The biotype A (with 12 capsular serotypes) was classified under a new genus Mannheimia due to disparities in 16S rDNA sequence, cultural and pathological characteristics.

COMMON FEATURES OF BIOLOGICAL MEMBRANES

Membranes are sheetlike, just a few molecules thick and form closed boundaries between cell compartments.

Membranes contain lipids and proteins, with small amounts of carbohydrayes linked to the lipids and proteins.

Lipids in membranes are small with hydrophobic and hydrophilic portions. Lipid bilayers provide a barrier to the diffusion of polar molecules.

Characteristic functions of membranes are mediated by specific proteins, serving as pumps, channels, receptors, energy transducers and enzymes.

Membrane components associate through noncovalent interactions.

Membranes are asymmetrical, with two sides of the membrane differing from each other.

Lipid and protein molecules often diffuse rapidly in the plane of the membrane.

Central transport of ions and molecules into and out of the cell.

Generate proton gradients for ATP production by oxidative phosphorylation.

Receptors bind extracellular signals and transduce the signal to cell interior.

Clinical conditions similar to brucellosis have been described since the time of Hippocrates (450 BC). J. A. Marston (1861) first described brucellosis as gastric remittent fever in Malta, the Southern European island country. Sir David Bruce (1886) first isolated small coccobacilli from an infected soldier’s spleen and purified the culture in 1887, and named Micrococcus melitensis. Later the genus was renamed as Brucella in his honour. Similarly, Bang and Stribolg (1897) first isolated Brucella abortus from abortion material of a cow. Traum in 1914 isolated Bacillus abortus suis, currently known as Brucella suis. In 1953, Brucella ovis was firs isolated in New Zealand by Budlle and Boyes from the aborted material of sheep. Carmichael and Bruner (1968) first isolated B. canis from the aborted placenta of a dog.

In India first report of ‘contagious abortion’ associated with Brucella was found in annual report (1918) of imperial veterinary research institute (presently Indian veterinary research institute), Mukteswar, Uttarakhand and later in 1942 by Polding.