Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Winter course I > Microbiology and parasitology > Flashcards

Microbiology and parasitology Flashcards

1
Q

what is the definition of microbial resistance?

A

decreased susceptibility of a fungal strain to an antifungal agent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

why can microbial resistance occur?

A

intrinsic resistance or acquired resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the definition of clinical resistance?

A

therapeutic failure; a patient responds inadequately to an antifungal drug following administration of a standard dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the mode of action of polyenes?

A

bind to ergosterol and form aqueous pores in the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

name the 3 mechanisms of acquired resistance for polyene

A
  1. reduced amounts of ergosterol in cell membrane
  2. alteration of fungal cell membrane
  3. alteration of the fungal cell wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the mode of action of azoles?

A

inhibit the biosynthesis of ergosterol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

name the 5 mechanisms of azole resistance

A
  1. target is changed; reduced drug-target interaction
  2. increase in target copy number
  3. reduction of intracellular drug concentrations mediated via drug efflux transporters and reduced uptake
  4. modification of other ergosterol biosynthesis pathway elements
  5. biofilms and persistor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the mode of action of echinocandins?

A

inhibit the synthesis of B-glucan in fungal cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

name the 4 fungal drivers of resistance

A
  1. stress pathways
  2. generate tolerate cells
  3. mutations rise
  4. stable resistant isolates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

name the 3 mechanisms of echinocandin resistance

A
  1. target is changed
  2. increase in target copy number
  3. biofilms and persistor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the difference between intrinsic and acquired resistance?

A

intrinsic resistance is natural resistance to anti-fungal drugs without any previous exposure and acquired resistance is resistance acquired through genetic mutation and passage of these resistant genes after exposure to drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

name the 3 types of Staphylococcus aureus carriers and describe them

A
  1. non carriers; resistant to colonization of S. aureus
  2. intermittent carriers; colonization with unique S. aureus genotype
  3. persistent carriers; colonization with one unique strain and resistant to colonization with different strain of S. aureus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which type of S. aureus carriers are at high risk for endogenous S. aureus infections?

A

persistent carriers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

which microbial factor is involved in the nassal carriage of S. aureus?

A

staphylococcal protein A (SpA) is positively correlated with carriage duration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

name the 4 characteristics of a pneumococcal co-infection with influenza virus

A
  1. epithelial damage
  2. decreased mucociliary velocity
  3. reduced CCL2 expression
  4. reduced macrophage functionality
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does the pneumococcal capsule contribute to disease?

A

capsule virulence factor is resistant against phagocytosis

17
Q

what is competence in S. pneumoniae?

A
  • horizontal gene transfer; transformation
  • competence is induced by environmental signals (high cell density, stress)
  • competence leads to killing neighboring cells
  • competence stimulating peptide (CSP) secreted by competent cells
18
Q

which proteins are essential for niche adaptation?

A

ATP binding cassette (ABC) transporters for nutrient transport

19
Q

what is the function of pneumolysin?

A

toxin that form pores to induce inflammation for faster clearance and increased transmission

20
Q

name the 3 prominences of S. pneumoniae as a cause of disease

A
  1. high carriage rates
  2. genetic adaptibility
  3. ability to shift from commensal to a pathogenic interaction with its host
21
Q

name the 2 adaptations that is needed for niche adaptation

A
  1. metabolic adaptation; maintenance of metal levels, different carbon sources
  2. immunological adaptation; from non-sterile to sterile site
22
Q

name the 3 limitations of current pneumococcal vaccines

A
  1. protection against a limited number of serotypes
  2. pneumococcal vaccines are designed based on prevalence in US and Europe
  3. expensive and complex from a development and manufacturing perspective
23
Q

name the 5 requirements for an improved pneumococcal vaccine

A
  1. broadly protective
  2. affordable
  3. target groups: infants and elderly
  4. focus on reduction of carriage
  5. potential novel vaccine antigens based on conserved proteins required for colonization
24
Q

name the 3 current pneumococcal vaccines

A
  1. conjugate vaccines (PCV); purified capsular polysaccharides conjugated to carrier proteins
  2. PPV23; purified polysaccharides
  3. adjuvanted with aluminium phosphate; Th2 adjuvant to increase antibody response
25
Q

what is the mode of action of B-lactam antibiotics?

A

interrupt cell wall synthesis by binding to penicillin-binding proteins (PBPs) that are essential for peptidoglycan crosslinking

26
Q

name the 3 mechanisms of resistance of B-lactam antibiotics

A
  1. impaired permeability of outer membrane
  2. mutated penicillin binding proteins (PBPs) with changed affinity
  3. enzymatic hydrolysis of the B-lactam ring
27
Q

what is the mode of action of aminoglycosides antibiotics?

A

inhibit protein synthesis by binding to the 30S ribosomal subunit

28
Q

name the 3 mechanisms of resistance of aminoglycosides

A
  1. aminoglycoside-modifying enzymes
  2. alteration in uptake
  3. change in ribosomal binding sites (methyltransferases)
29
Q

name the mode of action of quinolones antibiotics

A

inhibit DNA synthesis; the activity of DNA gyrase and topoisomerase IV

30
Q

name the 5 mechanisms of resistance of quinolones

A
  1. mutations in DNA gyrase and topoisomerase IV
  2. decreased porine-expression
  3. activation of efflux pumps
  4. inability of the quinolone to bind to the gyrase by hindering of the interfering protein encoded by qnrA
  5. degradation by acteyltransferases aac(6’)-1b-cr
31
Q

name the 7 risk factors for acquiring ESBL-E amongst travellers

A
  1. traveller’s diarrhoea
  2. antibiotic use during travel
  3. travelled to South Asia
  4. behaviour during travel
  5. food consumption during travel at street food stalls
  6. male gender
  7. older age
32
Q

what is the definition of ESBL?

A

extended-spectrum beta-lactamase; beta-lactamases capable of conferring bacterial resistance to antibiotics by hydrolysis of these antibiotics

Winter course I (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions