Brainscape's Knowledge GenomeTM

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


See full index

Micro > Week 14 Exam 4 > Flashcards

Week 14 Exam 4 Flashcards

1
Q

Goal of Antimicrobial chemotherapy

A

administer a drug to an infected person that destroys the infective agent without harming the hosts cell

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

a drug must be able to:

A
  • be easy to administer and able to reach the infectious agent anywhere in the body
  • be toxic to the infectious agent and nontoxic to the host
  • remain active in the body as long as needed and be safe and easily broken down and excreted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

prophylaxis

A

use of a drug to prevent infection of a person at risk

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

antimicrobials

A

all-inclusive term for any antimicrobial drug

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

antibiotics

A

inhibit or destroy bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

semisynthetic drugs

A

drugs that are chemically modified in the lab

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

synthetic drugs

A

drugs produced entirely in the lab

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

narrow-spectrum (limited spectrum)

A

antimicrobials effective against a limited array f microbial types
-a drug effective mainly against gram positive bacteria

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

broad-spectrum (extended spectrum)

A

antimicrobials effective against a wide variety of microbial types
-a drug effective against both gram positive and negative bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what factors must be known before antimicrobial therapy can begin?

A
  • the identity of the microorganism causing the infection
  • the degree of the microorganisms susceptibility (or sensitivity) to various drugs
    • disc-diffusion test: kirby bauer & E-test
    • tube-diffusion test: MIC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Disk Diffusion Test

A
  • surface of an agar plate is spread with test bacterium
  • small discs containing a prepared amount of antibiotic are placed on the plate
  • zone of inhibition surrounding the discs is measured and compared with a standard for each drug
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Tube dilution test

A
  • antimircobial is diluted serially in tubes of broth
  • each tube is inoculated with a small uniform sample of pure culture, incubated and examined
  • minimum inhibitory concentration MIC: smallest concentration (highest dilution) of drug that visibly inhibits growth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q
  • broad-spectrum:

- narrow-spectrum:

A
  • broad-spectrum: effective against more than one group of bacteria
  • narrow-spectrum: target a specific group
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how do bacteria in biofilms behave?

A
  • often unaffected by antimicrobials
  • antibiotics often cannot penetrate the sticky extracellular material surrounding biofilms
  • bacteria in biofilms express a different phenotype and have different antibiotic susceptibility profiles than free living bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

treating fungal infections

A

fungal cells are eukaryotic, present special problems in chemotherapy:

  • drugs designed to act on bacteria are ineffective against fungi
  • similarities between fungal and human cells mean that drugs toxic to fungi will harm human tissues
  • only a few agents with special anti fungal properties have been developed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

treating protozoal infections

A
  • anti-malarial drugs

- ameobicies

17
Q

treating helminth infections

A
  • flukes, tapeworms, and roundworms are larger parasites.
  • theri physiology is much more similar to humans
  • blocking reproduction doesn’t effect adult worms
  • most effective drugs immobilize, disintegrate, or inhibit the metabolism of all stages of the life cycle
18
Q

treating viral infections

A
  • infectious agent relies on a host cell for the vast majority of its metabolic functions
  • disrupting viral metabolism requires disruption of cellular metabolism of host
  • inhibition of virus entry: receptor/fusion/uncoating
  • inhibition of nucleic acid synthesis
  • inhibition of viral assembly/release
19
Q

antimicrobial resistance:

A

-adaptive response in which microorganisms begin to tolerate an amount of drug that would normally be inhibitory

due to genetic versatility & adaptability of microbial populations
microbes become newly resistant to a drug after one of the following occurs:
-spontaneous mutations in critical chromosomal genes
-acquisition of entire new genes or sets of genes via horizontal transfer from another species

20
Q

replacing normal flora terms;

  • probiotics:
  • prebiotics:
  • fecal transplants:
A
  • probiotics: preparations of live microorganisms fed to animals and humans to improve intestinal biota
  • prebiotics: nutrients that encourage the growth of beneficial microbes in intestine
  • fecal transplants: transfer of feces from a healthy patient via colonoscopy
21
Q

drugs can adversely affect the following organs:

A
  • liver (hepatotoxic)
  • kidneys (nephrotoxic)
  • GI tract
  • respiratory tract
  • nervous system (neurotoxic)
  • skin
  • bones and teeth
  • cardiovascular system and blood forming tissues (hemotoxic)
22
Q

Allergic reactions to antimicrobials

A
  • drugs act as an antigen that stimulates an allergic reation
  • can be provoked by the intact molecule or by metabolic alteration of the drug
  • allergies have been reported for every major drug
  • penicillin is most common
  • sensitization occurs during the first contact with the drug
  • second exposure can lead to hives, respiratory inflammation, or anaphylaxis
23
Q

what should every health care professional be critically aware of?

A

admirable & utilitarian nature of antimicrobials and of their limitations

24
Q

flu virus

A
  • segmented RNA genome
  • orthomyxoviridge
  • 3 types: A, B, C
  • enveloped with hemagglutinin & neuraminidase glycoproteins
25
Q

flu replication

A
  1. attach to militated epithetical cells via HA protein
  2. entry by endocytosis
  3. uncoating occurs in endosome &mediated by drop in pH
  4. synthesis in nucleus by RNA dependent transcriptase, cap snatching allows for translation by host cell machinery
  5. assembly of genome and capsomeres in nucleus
  6. release by budding through cytoplasmic membrane
26
Q

flu symptoms and treatment

A
  • fever, muscle aches, lack energy, sore throat, nasal congestion, cough
  • incubation period 1-2 days
  • vaccines are 80-90% effective
  • amantadine and rimantadine prevent type A but no type B, target viral uncoating
  • neuraminidase inhibitors (zanmivir and aseltamivir) are effective against both A & B
27
Q

flu endemics

A
  • genetic drift: mutation in genes for viral surface proteins, typically HA/Na
  • makes immunity from previous flu infections less effective: epidemics
  • antigenetic drifts: reassert of genomes, 2 different strains of flu infect same cell and incorporated into new capsid

Micro (8 decks)

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