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29 terms

Microbiology Exam 3-answers

Which bacterium causes peptic (stomach) ulcers?
Heliobacter pylori
Which bacterium can cause pelvic inflammatory disease?
Neisseria gonorrrhoeae, Chlamydia trachomatis.
Septicemia could be used to describe the condition when _____________ are detected in the blood stream.
Yersinia pestis cells, botulinum toxin molecules, Human Immunodeficiency Virus particles
Vibrio cholerae.........
is a bacterium that causes extreme diarrhea
Which of the following can opsonize bacteria?
Antibodies & C3b
How can complement be activated (according to our discussions and your notes in class)?
Bacteria opsonized with antibodies can activate complement.
Gram negative bacteria release lipid A (part of lipopolysaccheride) from their cell wall when they die. What do we call this released lipid A?
Which causes typhoid fever?
Salmonella Typhi
Which are the signal molecules used for communication between cells of the immune system?
Which immune cell type(s) that we discussed contribute to allergies?
T helper 2 (Th2) cell & Basophils & mast cells
An animal that transmits a disease agent to humans or other animals is termed a ______________?
disease vector
Which immune cells are the professional phagocytes that quickly appear at the site of an infection in large numbers?
Treponema species can cause....
Trench mouth & Syphilis
Severe diarrhea with mucous and blood is termed....
Macrolides inhibit
the prokaryotic ribosome
Which is/are examples of A-B toxin(s)?
The toxin produced by Corynebacterium diphtheriae & Cholera toxin
Briefly explain the basic principle of a vaccine.
The principle of a vaccine is exposing an animal to antigens from a particular pathogen to generate a primary immune response to those antigens. The goal of a vaccine is to provide protection to that organism by generating immunological memory. Memory immune responses happen more quickly and 'strongly' and can prevent the 'host' from every experiencing symptoms or prevent them from becoming infected at all. An example from our video would be neutralizing antibodies that prevent a virus from entering host cells.
What is an aerosol and why is it significant in understanding disease transmission?
Aerosols are tiny microscopic droplets that contain a disease agent, often respiratory. They can promote disease transmission because they can easily spread pathogens to uninfected persons when infected persons sneeze or cough and generate aerosols.
List two ways that the causative agent of "whooping cough" causes severe coughing.
Bordetella pertussis kills ciliated cells in the lungs and increases mucus production.
Why don't sulfa drugs affect human cells (explain with as much correct information as you can remember)?
Humans and bacteria need folic acid to make aromatic molecules like nucleotides and some amino acids. Humans absorb folic acid (aka folate) from the environment as part of their diet. Folate is a B-vitamin. Bacteria must synthesize their own folic acid. Sulfa drugs don't affect human cells because they inhibit an enzymatic pathway responsible for making folic acid.
List 3 phenotypic changes that can allow bacteria to resist anti-microbial drugs
1) Bacteria can mutate gene encoding the drug target so that the drug can no longer bind to the target, 2) Bacteria can destroy or alter the drug with, 3) Bacteria can express pumps with expel the drug
List three ways the native flora inhibit growth of pathogenic bacteria
1) They compete for space. 2) They compete for nutrients. 3) They actively secrete anti-bacterial.molecules (ex. bacteriocins & anti-biotics).
List 3 factors that contribute to the emergence or re-emergence of rare pathogens?
Microbial evolution, changes in technology, complacency and breakdown of public health.
B-cell activation: Describe 4 things (2 are cellular 2 are molecular) required for B-cell activation and where it generally happens. Make sure to indicate the status of any cells involved & how they achieved that status. Make sure to indicate on which cells (in this interaction) you find any molecules you describe. What is the function of an activated B-cell?
Where does it happen? Lymph node. Cell 1 (required to prepare cell #2) - Activated/mature antigen presenting cell (ex. dendritic cell). It became activated by detecting pathogens in the peripheral tissues. Cell 2 - Activated T-helper cell that became activated by recognizing its antigenic destiny being displayed on the surface of a mature dendritic cell. Molecular requirement examples:cytokines, TCR on T-helper cell must recognize its destined antigen on APC surface. BCR on surface of B-cell must recognize is destined antigen floating by in the lymph node. TCR on ACTIVATED T-helper cell must recognize antigen presented on surface of B-cell that found its antigenic destiny.
Function of activated B-cells
Produce antibodies
What is one mechanism the human body uses to limit the numbers of bacteria which colonize its surfaces (other than microbial flora)?
It regularly sheds cells from its surfaces; like the outer layer of skin cells falling off and being replaced by new cells.
What is an example of a body surface that is less effective than most other body surfaces at controlling colonization by microbes and therefore requires frequent mechanical removal of bacteria?
List the genus & species of the bacteria that the DTP vaccine protects against
Corynebaterium diptheriae, Bordetella pertussis, Clostridium tetanii.
List the genus and species of a corresponding disease agent for each disease below: A)Pneumonia, B) Periodontal disease (genus only), C) Syphilis D) Gonorrhea, E) Urinary bladder cystitis, F) Dental caries
A) Streptococcus pneumoniae, Haemophilus influenzae. B) Porphyromonas. C) Trepnema pallidum. D) Neisseria gonnorhoeae. E) Escherichia coli. F) Streptococcus mutans.