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46 Cards in this Set
- Front
- Back
What are the six important environmental factors for gene regulation?
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pH
oxygen nutrients iron availability osmolarity temperature |
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Bordetella pertussis morphology
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gram-negative coccobacilli
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What disease does Bordetella pertussis cause?
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pertussis (whooping cough)
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What demographic is an important reservoir for Bordetella pertussis?
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adults
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What demographic is most strongly effected by Bordetella pertussis infection?
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children under 5 years of age
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What is the host range of Bordetella pertussis?
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humans
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Does Bordetella pertussis survive in the environment?
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no
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What is the mode of transmission of Bordetella pertussis?
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aerosols or direct contact
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What are the four major virulence factors of Bordetella pertussis?
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adhesins (particularly for ciliated cells)
several toxins (ie pertussin) LPS tracheal cytotoxin (a peptidoglycan fragment) |
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___ ___toxin is a peptidoglycan fragment from Bordetella pertussis
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tracheal cytotoxin
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B. pertussis attaches to ___ cells of the ___ by an adhesin called ___
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epithelial cells
URT filamentous hemagglutinin A (FHA) |
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B. pertussis enters the cell after epithelial attachment (T/F)
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F. It stays attached to surface.
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Bordetella pertussis produces a ___toxin called ___ which induces synthesis of cAMP in the host cell.
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exotoxin
pertussin |
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What is the function of pertussin in Bordetella pertussis infection?
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induces cAMP synthesis in host cell
causes more production of receptors for FHA |
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How is pertussin similar to cholera toxin?
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both induce cAMP production
similar in structure as well |
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What Bordetella pertussis toxin leads to more attachment of bacteria?
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pertussin production -> ++cAMP -> ++receptor for FHA -> B. pertussis attachment with FHA adhesin -> pertussin production
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What does Bordetella pertussis tracheal cytotoxin do?
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specifically kills ciliated cells, leading to extrusion from epithelium
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What does Bordetella pertussis adenylate cyclase toxin do?
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triggers increased mucous production, which inhibits leukocyte movement and phagocytosis
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What does Bordetella pertussis dermonecrotic toxin do?
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causes hemorrhage of blood vessels -> cell death, tissue destruction
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What is the length of the Bordetella pertussis incubation period?
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7-10 days
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Are disease symptoms present during Bordetella pertussis incubation?
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no
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What is the first stage of Bordetella pertussis infection called?
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catarrhal phase
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What is the second stage of Bordetella pertussis infection called?
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paroxysmal phase
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What is the only certain method for making a pertussis diagnosis?
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isolation of B. pertussis from nasopharyngeal swabs or secretions, and subsequent growth and identification with specific antisera
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Why are polymerase chain reaction and serology identification methods not used for Bordetella pertussis identification?
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lack of standardization
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Bordetella pertussis virulence factors are regulated by the "___" sensor-regulator system
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bvg
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The ___ (___) protein detects changes in environment, then phosphorylates the ___ protein
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sensor (kinase)
regulator |
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How does the regulator protein regulate virulence factor expression?
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transcriptionally activates FHA, pertussis toxin, adhesins etc. by binding DNA in promoter regions of each of the operons for the virulence factors
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T/F: In Bordetella pertussis the bvg system is always 'on'
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T
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T/F: Bordetella pertussis is found in the environment
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F
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Why is it advantageous for Bordetella pertussis to always express its virulence genes?
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not found in environment (only humans)
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Define operon
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a group of key nucleotide sequences including an operator, a common promoter, and one or more genes
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Define coccobacillus
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a baccilus (rod-shaped) that is so short it appears to be a cocci (sphere shaped)
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Bordetella pertussis evades host defences by colonizing a certain area. Describe this.
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preferential binding to ciliated cells between the entrance to the airway and the beginning of the lungs
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Describe Bordetella pertussis treatment
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primarily supportive
sometimes antibiotics |
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Describe the Bordetella pertussis vaccine (3 key components)
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purified antigens (pertussin toxoid, filamentous hemagglutinin, pertactin)
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What is pertactin?
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an adhesin molecule of Bordetella pertussis
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Are whole-cell preparations of Bordetella pertussis used in vaccination?
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no
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Why is it advantageous for Bordetella pertussis to always express its virulence genes?
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not found in environment (only humans)
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Define operon
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a group of key nucleotide sequences including an operator, a common promoter, and one or more genes
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Define coccobacillus
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a baccilus (rod-shaped) that is so short it appears to be a cocci (sphere shaped)
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Bordetella pertussis evades host defences by colonizing a certain area. Describe this.
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preferential binding to ciliated cells between the entrance to the airway and the beginning of the lungs
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Describe Bordetella pertussis treatment
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primarily supportive
sometimes antibiotics |
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Describe the Bordetella pertussis vaccine (3 key components)
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purified antigens (pertussin toxoid, filamentous hemagglutinin, pertactin)
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What is pertactin?
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an adhesin molecule of Bordetella pertussis
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Are whole-cell preparations of Bordetella pertussis used in vaccination?
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no
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