eChapters

A. Answer the following.

Q.1.     What are the key cytokines produced by Th1 cells ?
Ans.     IL-2 and IFN-g. 

Q.2.     What is class III MHC genes ?
Ans.    The class III MHC genes encode various secreted protein that have immune functions including component of C’ and molecules involved in inflammation.

B. Write true of false about the followings.

Q.1.     Macrophages, dendritic cells and B cells can acts as antigen presenting cells.
Ans.    True.

A. Answer the following.

Q.1.    Which protein is coded by gag gene in HIV ?
Ans.     It codes for protein that form the core (p24 and p17).

Q.2.     Which protein is coded by pol gene in HIV ?
Ans.    It codes for a protein that cleaved into 4 enzymes. 

Q.3.     Which protein is coded by env gene in HIV ?
Ans.    It codes for protein that is cleaved into two proteins (gp120 and gp41).

Innate immunity provides the first line of defense against invading pathogens. But if the pathogens are able to escape from the first line of defense mechanisms, the body uses, another set of immune mechanisms which provide defense in a more specialized manner. These are called second line of defense mechanisms. The second line of defense mechanisms are highly specific in nature. These are called adaptive immune response and provide adaptive immunity. It is also called acquired immunity since these immune responses are not present prior to the exposure of the microbes. When the body is exposed to foreign substances or microorganisms, body develops adaptive immune responses. Adaptive immunity is a set of specialized cells and processes that function to eliminate pathogens or prevent their growth.

When the body is exposed to a microbe or a foreign substance, the body makes some response which is called immune response. Immune responses are initiated by the interaction between a ligand, present on the surface of the microbe or secreted by the microbe or a foreign substance, and a receptor protein on the cell’s surface or a soluble receptor. There are several factors such as shape, charge and presence of other receptors which influence this interaction between the ligand and receptor. This ligand which is recognized by the immune system is called antigen. An antigen can be defined as an organism, a molecule, or part of a molecule which is recognized by the immune system. Often, the term immunogen is also used for antigen. Though, antigen and immunogen are used as synonyms but specifically, they are different from each other.

The interactions between antigens and antibodies are specific in nature in which an antibody recognizes an antigen through complementarities of shapes on paratope and epitope. An antigen reacts only with antibodies produced by itself or with closely related antigens. The reaction is similar to a lock and key. As a standard lock can be opened by its own key only similarly, an antibody can react only with its own antigen. Antibodies recognize molecular shapes (epitopes) on antigens.

The selection of right dog for the required purposes like watching, hunting, guarding, showing, companionship and even animal associated therapies nowadays, warrants a detailed information on various dog breeds, like physical and other specific characteristics which may be different to each other. This  chapter  gives important characteristics of dog breeds and guidelines for buying a pup.

1    Disease diagnosis based on posture, gait appearance and clinical signs

Classification of Organisms
Over the years, scientists have developed several systems for the classification of organisms. Greek phlosopher Aristotle (384-322 BC) grouped life forms as either plants or animals. Microscopic organisms were unknown at that time. Fungi were included in plants. Aristotle’s system distinguished only between plants and animals on the basis of movement, feeding mechanism, and growth patterns. In 1735, Carolus Linnaeus formalized the use of two Latin names to identify each organism, a system called Binomial nomenclature. He grouped closely related organisms and introduced the modern classification groups: kingdom, phylum, class, order, family, genus, and species. At that time singlecelled organisms were observed but not classified. This classification had two kingdoms.
Plantae: containing Plants and Fungi
Animalia: containing Animals
In 1866, Ernst Haeckel proposed a third kingdom- Protista, to include all single-celled organisms like amoebas and diatoms. Some taxonomists also placed simple multicellular organisms, such as seaweeds, in Kingdom Protista.
In 1938, Herbert Copeland proposed a fourth kingdom, Monera, to include only bacteria. This was the first classification proposal to separate prokaryotes from eukaryotes, at the kingdom level.
In 1957, Robert H. Whittaker proposed a fifth kingdom –Fungi.Fungi do not ingest food as animals do, nor do they make their own food, as plants do. They secrete digestive enzymes around their food, breaking it down before absorbing it into their cells.

1    Common diseases affecting livestock

2    Disease information

3    Diseases of skin

4    Diseases of muscuoskeletal system in canines

It is a discipline of science that describes handling, preparation and storage of food that can prevent food-borne diseases. When there are two or more cases of a similar illness from the ingestion of the same common food it is known as a food-borne disease outbreak (FSN, 2018). In order to avoid potential health hazards, food safety is very important. This needs safety between industry, market and the consumer. For food safety the labelling on food material is vital. This includes the origin of food, steps taken for food hygiene, food additives, pesticide residues, policies on biotechnology, food guidelines for the management of governmental import, export inspection and certification systems for foods. The food should be safe in the market with safe preparation and delivery of the food for the consumer. Foegeding et al., (1996) have done an assessment of risk factors with food borne pathogens.Warnock et al., (2007) have reported intervention to food safety.

When pathogens are in the food they may be transmitted to the consumer. It may result in an illness or death of the person or other animals. The pathogens include bacteria, viruses, molds and fungus. These multiply in the food medium. Joon et al., (2012) have found pathogenic bacteria in meat products of Korea. The developed countries have high intricate standards for the preparation of food; however, in the developing countries there are less standards and enforcement of the standards which are followed. Apart from food another major source of infection is water, which is very critical in spreading many diseases. It is possible to prevent food poisoning if good water is used for all purposes. However, it becomes difficult as in the food supply chain a large number of persons are involved apart from the fact that pathogens can be introduced into foods no matter how much precautions are taken. Cowden (2000) has studied the notification on food poisoning to improve health. Frenkel et al., (2015) studied the amount of wastes from food processing industries.

1    Large animals

2    Canines

3    Suggested antimicrobial/antifungal agents for intra-uterine administration

4    Commercial preparations of hormone(s) and recommended dosage protocol in cows

5    Drugs safe & contra indicated in pregnancy

Systematics
Domain : Bacteria
Phylum : Firmicutes
Class : Bacilli
Order : Lactobacillales
Family : Streptococcaceae
Genus : Streptococcus
Species : Str. agalactiae, Str.dysgalactiae, Str. equi subsp. zooepidemicus, Str.
uberis, Str. equi subsp equi, Str.suis, Str. canis, Str. pyogenes (human)
History
Rivolta (1873) described chain forming organisms in pus from a case of strangles in horses. In 1878-79, Pasteur recognized this organism as a pusforming agent. In 1903, Hugo Schottmuller introduced blood to differentiate various types of hemolysis. In 1928, Rebecca Lancefield reported a serological method of grouping Streptococci.
Habitat
Streptococci are worldwide in distribution. Most of the Streptococci of Veterinary interest live as commensals in the mucosa of the upper respiratory and lower urogenital tracts. They do not survive for long away from the animalhosts.

Laboratory investigation of the samples assist in diagnosing, confirming the cases including veterolegal cases. The type of material, quantity of specimens & preservatives used and the method of dispatch to the laboratory  is tabulated in this chapter.

Our general environment is loaded with tiny invisible living things that influence us consistently. Microbiology is a specialized area of science that deals with living things typicallytoo little to be seen without magnification. Suchmicroscopic life forms are collectively referred to as microorganisms. Microbial kingdom incorporates the study of bacteria, rickettsiae, viruses, fungi, algae and protozo a. Virology the study of viruses, mycology study of fungi and protozoology deals with protozoa.Credit for prologue to microbial world goes to ‘Antony van Leeuwenhoek’ and to vistas of microbial activities to ‘Louis Pasteur’ and ‘Robert Koch’. This period is reffered as the “Golden Era” of microbiology on account of the significant discoveries viz: microbial fermentations, discovery of various disease-causing agents, microbes’ cultivations, differences in metabolic activities, development of attenuated strains and their use as immunoprophylactic agents. The techniques used to study bacteria and different microorganisms embody direct microscopic examination, cultivation, biochemical tests, animal inoculation, serological reactivity and recent molecular biological techniques.Definitive evidence for the cause of a given infection is established by Koch that are still used to this day to definitively prove that a microorganism causes a particular disease. Koch’s four postulates are:

Chemotherapy

Chemotherapy is branch of pharmacology that deals with study of chemical substance intended to kills or inhibits the growth of invading microorganism or foreign cell without harm to host cells. Paul Ehrlich coined the term chemotherapy and is known as father of chemotherapy. Gerhard Johannes Paul Domagk discovered sulphonamide (sulfonamidochrysoidine). First commercially available sulphonamide marketed in the form of Prontosil dye, for which he received the 1939 Nobel Prize in Physiology or Medicine. SelmanAbraham Waksman discover streptomycin and several other antibiotics from soil actinomycetes and actinomycetes is called treasurer house of antibiotics.

α-lactam antibiotics- includes penicillins, cephalosporins, carbapenems, monobectum and beta-lactamase inhibitors. It inhibits bacterial cell wall synthesis due to inhibition of transpeptidation reaction thus inhibits peptidoglycan synthesis. Penicillins contain 6-animopenicillanic acid (((lactam ring + thiazolidine ring) eg. natural penicillins, beta-lactamase-resistant agents, aminopenicillins, carboxypenicillins, and ureidopenicillins. Discovery of penicillin was done by Alexender fleming from penicillium mold in 1928 from Penicillium notatum. Now a day’s Penicillium chrysogenum mold is a major source of penicillin production. Benzathine penicillin G is a repository salt of penicillin. Probenicid competitively inhibit renal tubular secretion of penicillin and increase the half- life of penicillin. Procaine penicillin G should not administer by i.v. route due to adversely affect the cardiac conducting system. Beta-lactamses inhibitors are calvulenic acid (Streptomyces clavuligerus), salbactum, tazobactam. They are called suicidal /progressive inhibitors. Main adverse effect associate with penicillin is immediate type of hypersensitivity reaction due to Antigen+ IgE antibody reaction.

At times, we hear our young generation questioning the need for obtaining degrees for conducting any research work. To some extend they are right. If we look back, there are many examples where persons without any former degree attained what is impossible by many degree holders. Tulsidas has written ‘Ramacharitmanas’, incorporating so many principles of Vedas and stories from Puranas without obtaining any degree. Srinivasa Ramanujan (21) narrated mathematics theorems without any degree in mathematics. His achievements may be appreciated by the fact that we celebrate his birthday 22nd December as National Mathematical day.

Introduction

For proper and efficient experiment to be conducted, experimenters need so many chemicals to deal with. This includes different acids, base, salt, different kind of indicators and so on. Some of these chemicals are safe for health, but some of them are dangerous to health when come in close proximity to our body while some of the chemicals cause health issues on inhaling. These may cause improper functioning of some of our physiological activities. Acids and bases are very dangerous for our tissues when come in our contact. These may cause serious respiratory problem in addition to injuries on coming to our contact. Some chemicals are exploratory yet they may cause even death of the person working with them in laboratory. Therefore, mere use of the chemicals in laboratory is not only the objective of the experimenter. The person working in laboratory should also be concerned about the proper use and handing of the chemical while working with it. Thus, every researcher of an institution who has to work with chemicals in a laboratory should be made aware about the chemicals to be used in the laboratory and the consequences if any mishandling of a laboratory chemical occurs. Not only these, suitable precautionary measures should also be known to the researcher along with ensuring the availability of the required safety equipment/installations. Hence, a proper understanding of the ways of handling of chemicals in a laboratory is of prime importance for the personals like you who are working or have to work in laboratory.

Safe Handling of Chemicals in Laboratory

Safe use/handling of chemicals in laboratory include minimized exposure to chemicals, maintaining safety data sheets, proper labelling, storage, segregation, and transport of chemicals for personal hygiene.

Since mouth pipetting of liquid reagents in a laboratory is not advisable, different tools are needed for safe, easier, and precise dispensing of liquid reagents. This chapter is devoted to make you aware of the tools like vacupette and micropipette which can be used for the handling of liquid reagents in a safe and precise way.

Vacupette

Glass pipettes have been traditionally used by sucking liquid solvent/solution directly using mouth. For safety reasons, mouth pipetting is no longer permitted in a laboratory. Hence, to fill a pipette vacupette is used by placing it on the top of glass or plastic pipette. It acts as a device to create vacuum for filling reagent in the pipette as well as for releasing the reagent with mechanical regulation on the flow out of the liquid. Vacupette can be of different types.

1. Rubber Bulb Vacupette

Rubber bulb vacupette is often used to transfer (pump up and discharge) liquid using a pipette when a larger quantity of chemicals is to be transferred. Small/tiny rubber bulb is attached to glass/plastic pipette for drawing little amount of reagents. Small vacupette is used to precisely discharge smaller volume/ drops.

Handling of Vacupette

• Insert the top of a pipette in the bottom of the rubber bulb vacupette (Figure 6.1).

• Remove air from the pipette by squeezing valve “A” at the top of the vacupette while simultaneously squeezing the rubber bulb. The amount of air released depends on the size of the rubber bulb.

Introduction

In a research laboratory, we frequently need weigh chemicals and prepare different solutions of varying strength, as per the requirements. Accuracy in weighing and preparation of solution, with respect to weight/volume and strength, determines the success of experiment. In turn, the accuracy depends on weighing of solid chemical and/or measuring the volume of liquid chemical/making up the volume. In this Chapter, weighing of chemicals using appropriate weighing balance, preparation of solutions of different strength, their dilution, and precautions while preparing will be discuss in brief.

Weighing of Chemical

The primary method to determine the amount of chemicals to be used is weighing the chemical by using a balance.

In general, there are two types of balances to weigh chemicals in a laboratory:

1. Standard laboratory balance

2. Analytical balance

Standard Laboratory Balance

Generally, a standard laboratory balance is used for weighing a chemical when an error of ±0.02 g is acceptable. It is also used for pre-weighing, where approximate mass needs to be determined. Precise mass of the chemical is then determined using an analytical balance. Following are the steps in using a weighing balance in a laboratory.

Introduction

Today, antimicrobial resistance (AMR) has become a global issue, contributing to rise in mortality and cost of treatment. Antimicrobial resistance (AMR) is the resistance of a microorganism against an antimicrobial agent to which it was originally sensitive (WHO, 2013). Dispersion of antibiotics is done at large scale, in India even sometimes without any proper prescription. Animal Husbandry is not untouched and antibiotics are used to a great extent, which needs enforcement of strict government rules and regulations for their use in f ield conditions (PHFI, 2011).

Extended-spectrum β-lactamases (ESBLs) are enzymes that hydrolyse most of the β-lactam antibiotics and thus mediate resistance to penicillins, 3rd and 4th generation cephalosporins (Saravanan et al., 2018). Beta-lactamase inhibitors, inhibit these ESBLs such as clavulanic acid, sulbactam and tazobactam (Trott, 2013). The genes encoding for these enzymes are commonly found both on the chromosomes and plasmids among Enterobacteriaceae family (Kotsoana et al., 2019).

Among Enterobacteriacae, E. coli and Klebsiella species are main environmental pathogens associated with various illnesses such as acute bovine mastitis (Koovapra, 2015), pathogenic E. coli with diarrhoea and extra intestinal infections in humans and animals (Levine et al., 1987), K. pneumoniae with respiratory and urinary tract as well as bloodstream infections (Daehre et al., 2018). Resistance to extended-spectrum β-lactams occurs mainly in members of Enterobacteriaceae family through plasmids encoded ESBL genes. (Sharma et al., 2010).