Microbiology with Diseases by Taxonomy Chapter 17 Answers

Microbiology with Diseases by Taxonomy Chapter 17 Answers

Microbiology with Diseases by Taxonomy Answers

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1CM
The concept map represented below describes about vaccines. Individuals can be protected against microorganisms by active immunization. Active immunization involves giving antigen in the form of live vaccine, killed vaccines, and toxoid vaccines.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1CT
The disease prevalence and the mortality rate of infected persons are the factors determined. The disease prevalence, explains about the percentage of the disease in a particular population. The mortality rate is an indicator of the death percentage in a particular population per unit time. For example, if the disease causes death only infrequently and does not affect a majority of the population, approval of a vaccine that causes severe illness in 1% of the patients is not ethical.
The cost-benefit ration must be carefully examined in this situation. On the other hand, if the disease infects a large percent of the population, and has a significant mortality rate, a vaccine that causes 1% of patients to be seriously ill should be approved if it protects immunized individuals from contracting a potentially fatal infection.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1L
The fig 1L represents the following explanation:
Antibody is added to ELISA (enzyme linked immunosorbant assay) well. Excess antibody is removed by washing. Gelatin is added to cover any portion of the well, which is not covered by antibody. Moreover, antigen is added, followed by the addition of enzyme-labeled anti-antibodies to the well. The enzyme substrate is added to the well, giving a colored product. Therefore, the color is measured using spectrophotometer.
The chemicals in the picture, represented by artist’s conception of ELISA are, as follows:

• Gelatin.
• Substrate.
• Antibody bound to micro well.
• Color produced.
• Enzyme-linked antibody.
• Antigen in patient’s serum.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1M
Immunoglobulins induces rapid onset of immunity:
Explanation
Immunoglobulins are glycoproteins formed in response to an antigen and react specifically with antigen. The main function of immunoglobulin is protection of body against invading microorganisms. Moreover, immunoglobulins induces rapid onset of immunity. The protective role of antibody includes agglutination, precipitation, neutralization, opsonization, and phagocytosis. Thus, it could be ascertained that induces mainly an antibody response could be associated with immunoglobulin.
Thus, the statement, “induces rapid onset of immunity” matches to the term, “immunoglobulin”.
Hence, the correct option is D. Immunoglobulin.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1MC

• Immediate immunity against tetanus is achieved if the patient receives antibodies against tetanus toxin. It is otherwise called antitoxins. It comes under passive immunotherapy, where preformed antibodies are administered to the patient. This makes option (d) as the right choice.
• Attenuated vaccines of Clostridium tetani is an active immunization process in which immunity against tetanus will not be provided immediately. Hence, option (a) is incorrect.
• A modified live vaccine comes under active immunization, which does not provide immediate immunity against tetanus. Hence, option (b) is incorrect.
• Tetanus toxoid vaccines are modified using various chemical or thermal methods. These modified toxins can stimulate active immunity and the person cannot obtain immediate immunity against tetanus. Hence, option (c) is incorrect.
• Subunit vaccines are developed using the antigenic fragments of microbes; it is safer to use subunit vaccines than to use live vaccines, which stimulate active immunity. Hence, option (e) becomes incorrect.
• In order to obtain immediate immunity against tetanus, a patient should receive immunoglobulin against tetanus toxin (antitoxin). Hence, the correct answer is option (d) immunoglobulin against tetanus toxin (antitoxin).

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1SA
Contrast between Chinese practices of variolation with Jenner’s vaccination:
Explanation
In 12^th century, the Chinese started variolation procedure. The children who were recovered from smallpox are not affected from the disease, the second time. They started the technique of infecting young children with particles of ground smallpox scabs from children who survived after mild disease. By adapting this technique, Chinese reduced the population’s overall morbidity and mortality from smallpox. Even though the technique is effective and successful, variolation caused death from smallpox in 1-2% of recipients and in people exposed to recipients. Hence, this procedure was outlawed.
In 1796, an English physician Edward Jenner demonstrated protection against smallpox, by inoculating crusts from a person infected with cowpox. Cowpox is related to smallpox, but causes very mild disease. The new technique was named as vaccination, since cowpox was also called vaccinia. The protective inoculum is called vaccine. Thus, for many years, vaccination against smallpox was widely practiced.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 1TF
Passive immunotherapy is the administration of antiserum containing preformed antibodies that provides immediate immunity, but for a shorter time period. Passive immunotherapy does not provide prolonged immunity as in active immunization.
The passive immune therapy is mainly two types:

• Natural acquired passive immunotherapy
• Artificial acquired passive immunotherapy

Active immunization involves giving antigen in the form of vaccines, which provides prolonged immunity. The prolonged immunity is maintained with the help of memory B-cells.
Hence, the given statement, passive immunotherapy provides more prolonged immunity than active immunization is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2CT
False negative HIV test results are potentially more damaging than false positives. When a false negative result in a HIV patient, makes him believe that he is HIV negative, unknowingly he spreads the disease to others who are unaware of their risk.
A false negative result deprives the person of early interventions, which can increase their quality of life and perhaps extend their life. In a false positive result, the person becomes mentally stressed. The emotional trauma of a false positive can be considerable, but will fade when further testing demonstrates the person is not infected with HIV.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2M
Subunit vaccine induces an antibody response:
Explanation
Subunit vaccines are a type of inactivated vaccines. They are produced by antigenic fragments of microbes. They are safer than live attenuated vaccines. Moreover, subunit vaccines are antigenically weak, so they are often administered with adjuvants. The vaccines are recognized by the immune system as exogenous antigens, they stimulate an antibody immune response. Thus, it could be ascertained that subunit vaccines could be associated by inducing an antibody response.
Thus, the statement, “induces mainly an antibody response,” matches to the term, “subunit vaccine”.
Hence, the correct option is C. Subunit vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2MC

• Microbes in inactivated vaccines cannot reproduce, they do not present as many antigenic molecules to the body as do live vaccines; therefore, inactivated vaccines are antigenically weak. They are administered in high doses or in multiple doses, or incorporated with materials like adjuvants to increase antigenicity of the vaccine. This makes option (c) as the right choice.
• In attenuated vaccines, virulent microbes are normally not used, instead the virulence property is reduced, but they are still active and the pathogens no longer cause disease. Pathogens in attenuated vaccine can reproduce, they presents many antigenic molecules to the body that stimulate an immune response. Attenuated vaccine type is not given with an adjuvant. Hence, option (a) is incorrect.
• A modified live vaccine contains attenuated microbes. These vaccines cause very mild infections but no serious disease under normal conditions. Attenuated viruses in such a vaccine infect host cells and replicate. The vaccines contain active microbes; a large number of antigen molecules are available to stimulate immune response. Modified live vaccine type is not given with an adjuvant. Hence, option (b) is incorrect.
• Immunoglobulins are raised in our body when exposed to an antigen. They are not incorporated with materials like adjuvants. Hence, option (d) is incorrect.
• An agglutinating antigen clumps with antibodies specific to it. It does not come under vaccine type and they are not incorporated with adjuvants. Hence, option (e) is incorrect.
• Therefore, the correct answer is option (c) a chemically killed vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2SA
Advantages and disadvantages of attenuated vaccine:
Explanation
Attenuated vaccines are live vaccines in which pathogens are weakened, so that they no longer cause disease. The process of reducing virulence is called attenuation. This is done by rising numerous generations of viruses in tissue culture, until they lose the ability to produce disease. Modified live vaccines cause mild infections, but no serious disease under normal conditions. Similarly, attenuated viruses in a vaccine infect host cells and replicate the infected cells to process endogenous viral antigens. As a result, modified live viral vaccines trigger a cell mediated immune response. Individuals vaccinated with modified live vaccine can infect around them, providing contact immunity.
Hence, attenuated vaccines can be hazardous because modified microbes may retain enough residual virulence to cause disease in immunosuppressed people. Pregnant women should not receive live vaccines because of the danger that the attenuated pathogen will cross placenta and harm the fetus. During the year 2000, polio epidemic has occurred in which reversion of an attenuated live virus in oral polio vaccine is formed to virulent poliovirus. Thus, live polio vaccine was no longer used to immunize children in United States.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 2TF
Attenuation is the process of reducing virulence. It is done by rising numerous generations of the culture. The process of inactivating (or) killing is different from attenuating, since killed vaccines cannot replicate, revert, and mutate (or) retain residual virulence. They are safer than attenuated vaccines. It is not standard to attenuate killed virus vaccines. Hence, the given statement, It is standard to attenuate killed virus vaccines is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3CT
It is important that a serologic test reach the market at a reasonable cost. A costly serologic test is little used, no matter how reliable (or) important the results. Health management organizations usually reject expensive tests out of hand, and people who have no health care coverage generally do not have the means to pay.
The less technical skill a test requires the better. A serologic test that is difficult to conduct will produce unreliable results more frequently due to human error. Automation is important for tests that are done frequently, and in large quantities. A person may become bored (or) distracted; a machine does not. Efficient and reliable results are provided by a machine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3M
Attenuated viral vaccine induces cell mediated immunity:
Explanation
In attenuated viral vaccine, attenuated viruses infect host cells and replicate. Moreover, the infected cells process endogenous viral antigens. As a result, modified live viral vaccines trigger a cell mediated immune response, dominated by type 1 helper T cells (Th1) and cytotoxic T cells (Tc). Since, modified live vaccines contain active microbe, large number of antigen molecules are available to stimulate an immune response. Thus, it could be ascertained that induction of cell-mediated immunity could be associated with attenuated viral vaccine.
Therefore, the statement, “induces well cell-mediated”, matches with the term, “attenuated viral vaccine.”
Hence, the correct option is A. Attenuated viral vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3MC

• Vaccinia virus is widely used in attenuated live vaccine. It is administered subcutaneously. It includes poxvirus which causes small pox in humans. Vaccine developed against small pox is done by repeated sub-culturing of small pox antigen. The virulent property is removed and the antigenic property alone will be present. This makes option (b) as the right choice.
• Coronavirus can be a cause from severe common cold to SARS. Vaccine developed for coronavirus are mostly inactivated viral vaccine. To date, live attenuated vaccine has not been evaluated. Hence, option (a) is incorrect.
• Influenza virus causes flu disease. The vaccine developed against influenza is inactivated subunit vaccine in which only the antigenic fragment of influenza virus is used for vaccine preparation. This makes option (c) incorrect.
• Till now no proper vaccine has been developed against retrovirus. Attenuated live vaccination method cannot be applied to develop retroviral vaccine. Hence, option (d) is incorrect.
• Myxovirus is a group of viruses that cause influenza, mumps, and certain other disease. Killed virus is injected intramuscularly using adjuvant and this is given as vaccine. Therefore, option (e) is incorrect. Hence, the correct answer is option (b) vaccinia virus.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3SA
Advantages and disadvantages of passive immunotherapy and active immunization:
Explanation
Protection is required by passive immunotherapy with preformed antibodies, during immediate protection. Since, preformed antibodies are removed rapidly from the blood; memory B cells are not produced. Protection is temporary and the recipient becomes susceptible again.
Active immunization provides long-term protection that is capable of restimulation to produce memory cells. When active immunization is initiated before any exposure to Clostridium tetani has occurred, active immunization using tetanus toxoid develops, long-lasting protection that is readily available upon exposure to toxin.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 3TF
HIV infection cannot be diagnosed using a single serological test, since retroviral antigen modifies its epitope often. AIDS is not a single disease, it is a syndrome, and it causes opportunistic infection in patients. Many antibodies against HIV antigen will be produced in AIDS patients, so there are several chances of misinterpretation.
The various test used in the HIV diagnosis are ELISA (Enzyme linked imnuo sorbent assay), Western blotting, Antigen tests, Nucleic acid based tests and CD4-T cell count extra.
The ELISA is a common detective test, where Western blotting is termed as conformation test for HIV. The CD4- T cell test used to know the diagnosis of patient at what stage of disease.
Hence, the given statement, one single serologic test is inadequate for an accurate diagnosis of HIV infection is TRUE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4CT

• In addition to blood serum, the body fluids that may be used for immune testing include urine, saliva, cerebrospinal fluid, sputum, semen, and vaginal secretions. On occasion breast milk might also be used.
• The urine contains all the catabolic products of the human systems. The estimation of these catabolic products gives indirect information about the primary metabolic compounds and the enzyme activity associated with that particular primary metabolic compounds.
• The CSF is used for the diagnosis of the fatal bacterial, fungal and viral meningitis disease. The parameters studied in the CSF analysis are the amount of glucose, proteins and WBC analysis.
• The sputum samples are analyzed for the lung disease caused, by some bacterial species like Tuberculosis.
• The vaginal secretion is collected for the analysis Sexually transmitted diseases (STD). The STD includes syphilis and HIV.
• The breast milk is not commonly used, for the clinical diagnosis. It is analyzed, for the detection of lactose in tolerance condition.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4M
Adjuvants increases antigenicity:
Explanation
Adjuvants are substances that increase effective antigenicity of inactivated vaccine. Moreover, adjuvants are often combined with whole agent vaccines or subunit vaccines. Additionally, adjuvants are chemicals added to increase the ability to stimulate active immunity. Thus, it could be ascertained that increases antigenicity could be associated with adjuvant.
Therefore, the statement, “increases antigenicity,” matches with the term, “adjuvant.”
Hence, the correct option is B. Adjuvant.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4MC

• If antigen is excess the amount of precipitate declines. If antigen is too excess than antibody, there will not be any precipitation development. Maximal precipitation does not occur in antigen excess zone. Hence, option (a) is incorrect.
• When there is excess antibody, each antigen molecule is covered with many antibody molecules, preventing extensive cross-linkage and thus precipitation occurs. Immune complexes are small and soluble if the antibody is excess. Hence, option (b) is incorrect.
• Maximal precipitation occurs only when there is equal concentration of antigen and antibody. Precipitin line does not occur just by adding antigen to the antibody. Hence, option (d) is incorrect.
• When an unknown concentration of antibody is added to the antigen, precipitation does not occur. Maximal precipitation occurs only when there is equal concentration of antigen and antibody. Hence, option (e) is incorrect.
• When the reactants are in optimal proportion, the ratio of antigen to antibody is such that cross-linking and lattice formation are extensive. Thus when antigen and antibody are at equivalent concentration, maximal precipitation occurs. This makes option (c) as the right choice.
• Hence, the correct answer is option (c) antigen and antibody, are at equivalent concentrations.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4SA

• Precipitation tests are one of the simplest serologic tests, which rely on the fact that when antigens and antibody are mixed in proper proportions, they form huge, insoluble, and lattice-like complexes called precipitates.
• Precipitation tests are often performed in clear gels this is called “immunodiffusion.” In immunodiffusion technique, the antigen and antibody are placed in wells that diffuse out through the agar, where they meet in optimal proportions, and a line of precipitation forms.
• Another type of precipitation reaction is called “radial immunodiffusion.” In this technique, antigen in solution diffuses from a well into agar, which contains a known concentration of specific antibodies. The diameter of the ring of precipitate that forms around the antigen in the well is directly proportional to the concentration of antigen in the well.
• Not all antigens are soluble proteins that can be precipitated by antibody. Because of their multiple antigen-binding sites, antibodies can also cross-link particle. Such as whole bacteria (or) antigen-coated latex beads causing agglutination.
• “Agglutination” involves the clumping of insoluble particles, whereas precipitation involves the aggregation of soluble molecules. Agglutination reactions are easy to visualize and interpret with the unaided eye.
• Agglutination reaction is caused by “IgM antibodies,” more efficiently than IgG. Hemagglutination is a type of agglutination reaction, used to determine blood type in humans.
• Another use of agglutination is in a type of test that determines the concentration of antibodies in a clinical sample. The amount of these antibodies, called the titer, is measured by diluting the serum in a process called titration.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 4TF
Enzyme-linked immunosorbent assay (ELISA) has become a test of choice for many diagnostic procedures, such as determination of HIV infection. They are a family of simple serologic tests that can be automated efficiently and read easily, either by direct observation (or) by machine.
The ELISA technique mainly employed in three different methods: Indirect method, sandwich method, competitive method. In these methods the ultimate color product measured by using a spectrophotometer machine. The formed color product is proportional to the antibody present in the serum.
Hence, the given statement, ELISA is very easily automated is TRUE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5CT
Cross-reactive antibodies occasionally produce false positive results, when they are used in serological assays. Since, antigens from different sources are similar enough that antibodies reactive to one antigen will also react with the other antigen. Hence, serological test might give a false positive result.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5M
Subunit vaccine uses antigen fragments:
Explanation
Subunit vaccines are a type of inactivated vaccines. They are produced from antigenic fragments of microbes. However, subunit vaccines are safer than live attenuated vaccines. Thus, it could be ascertained that subunit vaccines could be associated with uses antigen fragments.
Therefore, the statement, “uses antigen fragments,” matches with the term, “subunit vaccine.”
Hence, the correct option is C. Subunit vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5MC

• Anti-antibodies are antibodies directed against other antibodies. An anti-antibody is used as secondary antibody to bind with primary antibody bound to an antigen. Hence, option (a) is incorrect.
• If antibody is not agglutinating then there is no use of using an anti-antibody, because it cannot go and bind to primary antibody. They would be washed off. Hence, option (b) is incorrect.
• An antibody does not activate complement. Anti-antibody is not used when an antibody does not activate complement. Hence, option (c) is incorrect.
• When antigen is insoluble, anti-antibodies are not used to make it soluble. Anti-antibodies bind only to primary antibody. Hence, option (d) is incorrect.
• It is possible to make an antibody that is directed against the antigen binding site of another antibody. This type of antibody is called anti-antibody, which is similar in structure to the original antigen.
• They both recognize the same antibody. This makes option (e) as the right choice. Hence, the correct answer is option (e) the antigen is an antibody.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5SA
Human chorionic gonadotropin is a hormone that is released during the early days of pregnancy. The HCG hormone act as biological marker used for the detection of pregnancy.
This hormone is produced only by an embryo (or) fetus. Increased levels of this hormone are found in all pregnant women. Immunochromatographic assay are faster and easier method used for pregnancy testing, which tests for human chorionic growth hormone.
The pregnancy test can be done by taking both urine and serum as samples. This test uses a monoclonal antibody that is specific for the ß sub unit of human chronic gonadotropin.
These monoclonal antibodies detect the enzyme labeled human chronic gonadotropin, and give the products either in color (or) luminescent form.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 5TF
A variation of the ELISA is the western blot test, which is used to detect antibodies against multiple antigens in a mixture. Western blot tests are currently used to verify the presence of antibodies against HIV in the serum of individuals, who are antibody-positive by ELISA. Compared to other tests, western blot tests can detect more types of antibodies and are less subjected to misinterpretation.
The western blotting involves the various techniques, like Electrophoresis, blotting, and ELISA. We can use the western blotting test for the diagnosis and confirmation of infection with HIV and diagnosis of Lyme disease. Hence, the given statement, ELISA has basically replaced the western blot test is FALSE.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6CT
A test to distinguish between B cells and T cells makes use of antibodies against surface antigens common to all B cells (BCR or other B cell specific molecule) and (or) to T cells (TCR, or other T cell specific molecule).
For example, a fluorescent molecule covalently attached to the constant region of antibodies specific for TCR, added to the mixture of lymphocytes and viewed with a fluorescence microscope. It would illuminate T cells only. The T cells are made visible because of the fluorescent molecule attached to them.
If the test requires both cell types be seen at the same time, two differently colored fluorescent dyes could be used, one on T cells specific antibodies, and the other on the B cell specific antibodies. As long as the antibody concentration is too low for agglutination and no complement factors are present, the T and B cells will not be killed in the process.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6M
Attenuated viral vaccine uses attenuated microbes:
Explanation
Attenuation is the process of reducing virulence. The most common method for attenuating viruses involves rising for numerous generations in tissue culture cells, until the viruses lose the ability to produce disease. However, attenuated viral vaccines contain attenuated microbes, which cause mild infections, but do not have serious disease under normal conditions. Additionally, attenuated viruses in a vaccine infect host cells and replicate; the infected cells then process endogenous viral antigens. Thus, it could be ascertained that attenuated microbes could be associated with attenuated viral vaccine.
Therefore, the statement, “uses attenuated microbes,” matches the term, “Attenuated viral vaccine.” Hence, the correct option is A. Attenuated viral vaccine.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6MC

• An anti-antibody test is used to measure the concentration of a specific human antibody. Antibodies directed against other antibodies are called anti-antibodies. Hence, option (a) is incorrect.
• A complement fixation test is a complex assay used to determine the presence of specific antibodies in an individual’s serum. The test can detect the presence of small amounts of antibody. Hence, option (b) is incorrect.
• A soluble antigen reacts with antibody to form huge, insoluble, lattice-like complexes called precipitin. Precipitation occurs when antigens are antibodies are in proper proportions. Hence, option (c) is incorrect.
• An agglutination test involves clumping of particulate antigen with antibody. Many different proteins in serum cannot be analyzed by agglutination test. Hence, option (d) is incorrect.
• An immunodiffusion test is used to indicate exposure to complex mixture of antigens. When multiple antigens and antibodies are placed in a well, multiple lines of precipitation show antigen-antibody combinations. This makes option (e) as the right choice. Hence, the correct answer is option (e) an immunodiffusion test.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 6SA
Herd immunity is the protection, provided all individuals in a population due to the inability of a pathogen to effectively spread, when a large proportion of individuals of more than 75% are resistant. It is important that patients follow the recommended immunization schedule, not only to protect themselves but also to provide society with herd immunity. Herd immunity only applicable to the diseases which shows contagious patterns.
Pathogens in the attenuated vaccines are weakened so that they no longer cause disease, though they are still alive (or) active and can provide contact immunity in unimmunized individuals who are associated with immunized people.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 7CT
Three ways of genetic recombinant techniques used to develop safer and effective vaccines:
Explanation
Genetic recombinant vaccines provide more effective, cheaper, and safer vaccines. They have been made to improve new vaccines, against pathogens that have been difficult to protect. Using recombinant method, the virulent genes are deleted selectively from pathogen, producing an irreversibly attenuated microbe that cannot revert to virulent pathogen.
The technique used to develop safer and effective vaccines are:

1. The genetic recombinant technique is used to produce large quantities of pure viral or bacterial antigens in vaccines. In this process, scientists isolate the gene that codes for an antigen and insert it into a bacterium, yeast, or other cell, which expresses the antigen.
2. Hepatitis B vaccine is manufactures using recombinant yeast cells. Alternatively, a genetically altered microbial cell or virus may itself be used as a live recombinant vaccine.
3. Another innovative method of immunization involves injection not of antigens, but instead of DNA that codes for antigen. For example, the DNA coding for a pathogen’s antigen can be inserted into a plasmid vector, which is then injected into the body.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 7MC

• In direct fluorescent antibody test, the serum used is not inactivated by heat. Instead, the sample containing suspected antigen is flooded directly with labeled antibody. Hence, option (a) is incorrect.
• The serum containing suspected antigen is flooded with fluorescent dye labeled antibody. If the suspected antigen is specific to labeled antibody, it fluoresces when observed under fluorescent microscope. The serum is not labeled with fluorescent dye, instead antibodies are labeled. Hence, option (b) is incorrect.
• Direct fluorescent antibody test are performed to determine specific antigen when labeled antibodies are flooded over it. It requires a fluorescent dye. Hence, option (c) is incorrect.
• A direct fluorescent antibody test does not require heated plasma. Here, antigen is directly flooded with fluorescent dye labeled antibodies. Hence, option (d) is incorrect.
• Fluorescent labeled antibodies are those chemically linked to a fluorescent dye. The test can be direct and indirect fluorescent antibody tests. In direct fluorescent antibody tests, tissue sample containing suspected antigen are flooded with labeled antibody and observed under fluorescent microscope. If suspected antigen is present, it fluoresces. This makes option (e) as the right choice.
• Hence, the correct answer is option (e) antibodies against the antigen.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 8CT
Difference between toxoid vaccine and attenuated vaccine:
Explanation
The following table depicts the difference between toxoid vaccine and attenuated vaccine:

Microbiology with Diseases by Taxonomy Chapter 17 Answers 8MC

• ELISA is abbreviated as Enzyme-Linked Immunosorbent Assay. It uses enzyme labeled antigen-antibody, which binds to antibodies attached to the antigen of interest. The intensity of color indicates positive test when the enzyme labeled antigen-antibody reacts with its substrate. This makes option (a) as the right choice.
• ELISA is abbreviated as Enzyme-Linked Immunosorbent Assay. Instead of a dye, enzyme is used which reacts with substrate to produce a colored product. a radioactive anti-antibodies are not used in ELISA. Hence, option (b) is incorrect.
• Complement is not used in ELISA test. Only enzyme labeled antibody is used which reacts with antibody-antigen complex and produces color. Hence, option (c) is incorrect.
• In ELISA test the well is coated with performed antigen which reacts with sample containing antibody against the specific antigen. Antigen-antibody labeled with an enzyme was added later. Hence, option (d) is incorrect.
• Antibody present in the sample reacts with antigen, which is already coated in well. When Antigen-Antibody labeled with an enzyme reacts with substrate then Ab binds to Ag, and produces color. An enzyme is labeled with antigen-antibody and not with antibody present in sample. Hence, option (e) is incorrect.
• Thus, the correct answer is option (a) an enzyme-labeled anti-antibody.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 9CT
Health organizations promote breast feeding of newborns to provide natural immunity.
Explanation
Breast feeding is very important for newborns. There are specific and innate immune factors present in mother’s milk to provide specific protection against pathogens in infants. In addition, immune factors in milk provide protection against microbial infections such as Haemophilus influenzae, Streptococcus pneumoniae, Vibrio chlorae, Escherichia coli, and rotavirus.
Hence, health organizations promote breast feeding of newborns because mother’s milk provide natural immunity to baby.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 9MC

• Direct fluorescent antibody test is performed to determine the presence of suspected antigen, which is specific to labeled antibody. When flooded with fluorescent labeled antibody to tissue sample containing suspected antigen, fluorescence indicate that antigen is specific to labeled antibody. This makes option (b) as the right choice.
• Direct fluorescent antibody test is used to detect the presence of suspected antigen. The fluorescent labeled antibody gives fluorescence, if the labeled antibody is specific to antigen. Haemagglutination is the clumping of red blood cells. Hence, option (a) is incorrect.
• Direct fluorescent antibody test is used to detect the presence of tissue sample containing specific antigen. It is not done to detect the presence of antibody. Hence, option (c) is incorrect.
• Complement is a heat-liable serum protein. In complement fixation test, we detect the presence of specific antibodies in an individual’s serum. Hence, option (d) is incorrect.
• Antigen-antibody complexes are not precipitated in direct fluorescent antibody test, instead they fluorescence since we label antibody with a fluorescent dye. When this labeled antibody binds to specific antigen it fluoresces. Hence, option (e) is incorrect. Hence, the correct answer is option (b) specific antigens.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 10CT
Contrast between hemagglutatination tests with viral hemagglutination inhibition test:
Explanation
The below table depicts the differences between hemagglutatination tests with viral hemagglutination inhibition test:

Microbiology with Diseases by Taxonomy Chapter 17 Answers 10MC

• Agglutination test is done to detect pregnancy and to diagnose salmonellosis, brucellosis, gonorrhea, rickettsial infection, mycoplasma infection, yeast infection, typhoid fever, meningitis caused by Hemophilus. Hence, option (a) is incorrect.
• Hemagglutination inhibition is performed to diagnose viral infections like influenza, but it is not used to detect rabies virus in the brain of a dog. Hence, option (b) is incorrect.
• Virus neutralization is performed to diagnose infections by specific strains of virus, but not specifically to detect rabies virus in the brain of a dog. Hence, option (c) is incorrect.
• Western blot is performed to verify the infection HIV and to diagnose lyme disease. Hence, option (d) is incorrect.
  • Direct immunofluorescence test is performed to detect rabies virus in the brain of a dog. The fluorescent dye labeled antibody binds to specific antigen in tissue sample and it fluoresces. This makes option (e) as the right choice. Hence, the correct answer is option (e) direct immunofluorescence.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 11CT
Medical personnel have eliminated the problem by switching on to inactivated polio vaccine:
Explanation
Attenuated oral polio vaccine (OPV) is very effective, as it causes clinical poliomyelitis, for every 1 in 2 million recipients or close contacts. However, attenuated viruses occasionally cause disease. It is not only found in fetuses and immunosuppressed patients, but also in healthy children and adults. Hence, medical personnel have eliminated the problem by switching on to inactivated polio vaccine (IPV).

Microbiology with Diseases by Taxonomy Chapter 17 Answers 11MC

• The virulence of the pathogen is reduced so, that the pathogen no longer causes disease. Attenuation is the process of reducing virulence by raising them for numerous generations in tissue culture cells until the virus loses the ability to produce disease. This makes option (a) as the right choice.
• Attenuation is the process of reducing virulence. It is not a necessary step in vaccine manufacture. Hence, option (b) is incorrect.
• A thin scraping from recovered children is injected into deliberately infecting young children, this procedure is called variolation. It is different from attenuation procedure. Hence, option (c) is incorrect.
• Adjuvants are substances that enhance antigenicity. Adjuvants are entirely different from attenuation since, attenuation is done to reduce virulence of a particular pathogen. Hence, option (d) is incorrect. Attenuation is (a) the process of reducing virulence.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 12MC

• An anti-antibody is an antibody often labeled with an enzyme that binds to primary antibody. Antiserum is different from antibody because antiserum binds to antigen, which triggers immune response. Hence, option (a) is incorrect.
• An inactivated vaccine (or) killed vaccine is where the antigen is killed and given as vaccine, which provides immunity to that particular antigen. Antiserum is different from inactivated vaccine, since it is produced in our body against particular antigen. Hence, option (b) is incorrect.
• Antiserum is blood serum containing polyclonal antibodies. Monoclonal antibodies are secreted by clones originated from a single plasma cell. Scientists have overcome the limitations of antisera by developing monoclonal antibodies. Hence, option (c) is incorrect.
• An antiserum is the liquid portion of blood which is otherwise called as “immune serum.” Antisera are typically collected from human blood plasma when exposed to an antigen. Antiserum contains polyclonal antibodies; they are particularly effective against pathogens which are capable of evading the immune system. This makes option (d) as the right choice.
  An antiserum is (d) the liquid portion of blood used for immunization.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 13MC

• Hybridomas are developed by fusing myeloma cells and antibody-secreting plasma cells. Each hybridomas divides continuously to produce clones of itself, and each clone secretes large amounts of a single antibody molecules. These identical antibodies are called monoclonal antibodies because they are secreted by clones originating from a single plasma cell. This makes option (a) as the right choice.
• Monoclonal antibodies are identical antibodies secreted by clones of single plasma cell. Each clone secretes large amount of a single antibody molecules. This makes option (b) as the right choice.
• Hybridomas are maintained in tissue culture to produce the antibodies needed for passive immunotherapy. Monoclonal antibodies are used to treat newborns infected with respiratory syncytial virus. Thus, monoclonal antibodies can be used for passive immunization. This makes option (c) as the right choice.
• Monoclonal antibodies are produced by fusion of myeloma cells with plasma cells results in hybridomas, the source of monoclonal antibodies. They are identical antibodies secreted by clones of single plasma cell. Monoclonal antibodies produced are used in passive immunization. This makes option (d) as the right choice. Monoclonal antibodies (d) all the above.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 14MC

• Attenuation is the process of reducing virulence. This process used in the vaccine production. It is not the study of antibody-antigen interactions in blood. Hence, option (a) is incorrect.
• Agglutination tests involve the clumping of insoluble antigenic particles by antibodies. Hence, option (b) is incorrect.
• Precipitation test involves mixing of soluble antigens with antibody in proper proportions, they form huge, insoluble, and forms lattice-like complexes called precipitates. Hence, option (c) is incorrect.
• Serology is the study and use of immunological tests to diagnose and treat disease and to identify “antibody-antigen interactions” in the blood. This makes option (d) as the right choice. The study of antibody-antigen interaction in the blood is (d) serology.

Microbiology with Diseases by Taxonomy Chapter 17 Answers 15MC

• Anti-human antibody antibodies are not found in immunocompromised individuals. Immunocompromised individuals are susceptible to various diseases since their immunity will be low. Antibodies against human antibodies are called anti-human antibody antibodies. Hence, option (a) is incorrect.
• Direct fluorescent antibody tests identify the presence of small amount of antigen in patient’s tissue. Labeled antibody is flooded over the antigen and examined under fluorescent microscope. Hence, option (b) is incorrect.
• When purified human antibodies are injected into a rabbit stimulate the rabbit to produce rabbit antibodies against the human antibodies. Such antibodies directed against other antibodies are called anti-antibodies. Hence, anti-human antibody antibodies are formed by animals reacting to human immunoglobulins. This makes option (c) as the right choice.
• ELISA is a simple test that can be readily automated and read by machine. These tests are among the most common serologic tests used. It is not an alternative method for anti-human antibody antibodies. Hence, option (d) is incorrect. The correct answer is option (c) formed by animals reacting to human immunoglobulins.