Download 221 exam 4

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Exam 4
Name ______________________________
Multiple choice. (1 point each) Choose the one best answer to each of the following questions.
____ A compound such as alum that is added to a vaccine to stimulate the immune response to vaccine components.
A. antiserum
B. antigen
C. adjuvant
D. epitope
____ A cell that recognizes microbial antigens displayed on a macrophage MHCII complex eventually leading to stimulation
of antibody production.
A. cytotoxic T cell
B. B cell
C. macrophage
D. T helper cell
____ Class of antibodies that is typically the first to appear in response to the presence of an infecting microbe.
A. IgA
B. IgE
C. IgG
D. IgM
____ Class of antibodies that primarily consists of two monomers linked together by a J chain and which is involved in binding
microbes to the mucin layer.
A. IgA
B. IgE
C. IgG
D. IgM
____ Small portion of a protein antigen that is recognized by antibody antigen-binding sites and is displayed by the antigenpresenting cell.
A. adjuvant
B. antibody monomer
C. complement
D. epitope
____ Vaccines are successful in preventing disease due to
A. the production of large quantities of antibodies that remain in the bloodstream and attach subsequent invading microbes.
B. production of long-lived "memory" cells that can quickly respond to invading microbes.
C. production of additional neutrophils that can seek out and destroy invading microbes.
D. production of more complement proteins that can increase the bodies response to subsequent invading microbes
____ Vaccine generated by fusing a polysaccharide to an immunogenic protein.
A. subunit vaccine
B. conjugate vaccine
C. toxoid
D. toxinoid
____ Why is Salmonella typhimurium being used for the development of a recombinant vaccine against Cholera?
A. Salmonella typhimurium is non-pathogenic.
B. Salmonella typhimurium closely resembles Vibrio cholera
C. Salmonella typhimurium targets the same tissues as Vibrio cholera.
D. Salmonella typhimurium is not being considered for recombinant vaccine development
____ A person who is infected with an organism but does not develop any symptoms is described as a(n)
A. nosocomial carrier
B. asymptomatic carrier
C. virulence factor
D. iatrogenic carrier
____ Which of the following is not an exotoxin?
A. tetanus toxin
B. pertussis toxin
C. diphtheria toxin
D. lipopolysaccharide
____ Diphtheria toxin attacks heart muscle cells and Tetanus toxin attacks neurons. If you fused the B portion of the tetanus
toxin to the A portion of the diphtheria toxin, what type of cell would the hybrid toxin attack?
A. heart muscle cells
B. neurons
C. neurons and heart muscle cells
D. none of the above
____ The component of the LPS of gram negative bacteria that is responsible for the effects of the toxin is the
A. core polysaccharide
B. lipid A
C. O-polysaccharide
D. dideoxysugar
____ Which of the following is an example of an arthropod borne disease?
A. Staphylococcus aureus food poisoning carried by a house fly.
B. Infant botulism carried by a bee that introduces Clostridium botulinum spores into its honey.
C. Rocky mountain spotted fever introduced by a tick while taking a blood meal.
D. All of the above are arthropod borne diseases.
____ Long lived T or B cells produced during an initial immune response that can respond quickly to subsequent infections.
A. macrophages
B. antigen presenting cells
C. cytotoxic cells
D. memory cells
____ A patient is suspected of having a viral infection and you need to quickly determine if viral particles are present in the
bloodstream. Which of the following protocols would you use?
A. ELISA – start with viral antigens bound to the wells of a microtiter dish, add patient serum, wash, add enzyme linked
secondary antibody, wash, add enzyme substrate for detection of antibody-antigen complexes indicating presence of virus.
B. ELISA – start with virus specific antibodies bound to the wells of a microtiter dish, add patient serum, wash, add enzyme
linked secondary antibody, wash, add substrate for detection of antibody-antigen complexes indicating presence of virus.
C. Western blot – Separate viral proteins by gel electrophoresis, transfer to a solid support membrane, add patient serum, wash,
add enzyme linked secondary antibody, wash, add enzyme substrate for detection of antibody-antigen complexes indicating
presence of virus.
D. It is not possible to detect viral particles in a patient’s serum.
____ Portion of an antibody molecule that is highly variable in amino acid sequence.
A. J chain
B, Fab fragment
C Fc fragment
D. phagocyte receptor binding site
Short answer. (1 point each)
A number of patients at PCRMC come down with infections all caused by a new emerging pathogen - Salmonella miner. DNA
from each isolate was subjected to Pulsed Field Gel Electrophoresis and the results are shown in panel A. Salmonella miner
was also isolated from a number of hospital sources. DNA from each hospital isolate was subjected to Pulsed Field Gel
Electrophoresis and the results are shown in panel B.
Which hospital source is the likely source of the outbreak?
How do you explain the result for patient F?
The figure on the left illustrates the results of a test to
determine the Minimal Inhibitory Concentration (MIC) of an
antibiotic that stops the growth of a strain of Streptococcus
pyogenes isolated from a patient. After incubation gray
indicates growth and colorless indicates no growth. What is
the MIC of this antibiotic for this particular strain of
Streptococcus pyogenes?
Is this strain of Streptococcus pyogenes sensitive,
intermediate or resistant to this antibiotic or is there not
enough information to classify its sensitivity?
List Koch's postulates.
Describe two roles for antibodies in fighting infection.
Why are nursing home patients particularly susceptible to nosocomial infections?
Describe one example of passive immunization.
Why doesn’t passive immunization confer long-term immunity?
What is herd immunity?
Some pathogenic microorganisms have distinct regions of their chromosomes, referred to as pathogenicity islands, that are
associated with virulence. Often these regions have a significantly different G:C content compared to the rest of the microbe’s
genome. Give one possible explanation for the differences in G:C content of the pathogenicity island.
Why is anthrax a “popular” choice for biological weapons?
A researcher studying Yersinia pseudotuberculosis suspects that a surface protein (YopZ) is responsible for colonization
leading to infection. The researcher develops a strain that lacks YopZ. To determine if YopZ is involved in infection she
determines the ID50 for the wild-type and mutant strains. The above graph illustrates the results of this experiment. Assuming
the researcher’s hypothesis is correct (YopZ is responsible for colonization leading to infection) label the above graph,
indicating which ID50 graph is for the wild-type strain and which is for the mutant strain.
The figure on the left illustrates the action of a specific type of
toxin. What type of toxin is it?
Name an organism that produces this type of toxin or a
disease associated with this type of toxin.
Short Essay Questions. Please answer four of the following five short essay questions (6 points each - 6 bonus points possible
for answering all 5 questions)
Our textbook describes several arthropod-borne diseases. Describe one advantage and one disadvantage to the microbe that
results from being transmitted by an arthropod vector. Select any of the described arthropod borne diseases and describe how
it is transmitted and how spread of the disease can be controlled.
List and describe four different types of vaccines, briefly discussing advantages and disadvantages of each.
Describe six factors of modern times that encourage the spread of infectious disease or that lead to "new" or re-emerging
diseases.
What are the possible consequences of nosocomial infections? (hint - also consider non-health related consequences)
Describe the mechanism by which an antigen presenting cell stimulates antibody production by B cells. Be sure to include all
necessary interactions.