Brainscape's Knowledge GenomeTM

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


See full index

Essential Medical Science (UoL, Medicine) > EMS Microbiology > Flashcards

EMS Microbiology Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards Biology 101 flashcards
1
Q

What are Koch’s Postulates?

A

Causative organism must be isolated from every sufferer
Organism must be cultivated in pure culture
Typical symptoms must result in an individual inoculated
Organism must be recoverable from individuals infected

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

What are koch’s postulates for genes?

A

The gene encoding the trait of interest should be present and transcribed/translated in a virulent strain

The gene encoding the trait should not be present or should be silent in a strain that does not cause disease

Disruption of the gene should result in the formation of a strain that is incapable of causing disease

Introduction of the gene into a strain that did not cause disease should make it cause disease

Gene must be expressed in infection

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

What are some problems with Koch’s postulates?

A

Difficulty to isolate organisms
Ethical obligations
Animal models may be sufficient

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

What are some characteristics of viruses?

A

Intracellular parasites
Nucleic acid core wrapped in a protein coat made of capsomeres
Some have an envelope
Retroviruses are unusual

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

What are some characteristics of microfungi?

A 
Eukaryotic
Cell wall made up of chitin
Hairy growths are moulds
Moulds have tiny filaments known as hyphae that form mycelia
Mycelia subdivided by septa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 4 classes of protozoa?

A

Apicomplexa
Flagellate Protista
Ciliate protista
Amoeba

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

Name some infections caused by protozoa?

A

Toxoplasmosis
Amoebic Meningitis
Malaria
Amoebic dysentery

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

What is mutualism?

A

Both organisms, in a symbiotic relationship, benefit

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

What is neutralism?

A

Neither organism, in a symbiotic relationship, derives benefit or harm

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

What is commensalism?

A

In a symbiotic relationship, one organism benefits and the other derives neither benefit nor harm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is parasitism?

A

One organism, in a symbiotic relationship, benefits at the expense of the host

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

What is the difference between sterile and non sterile sites?

A

Sterile sites have no normal flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How is sterility maintained?

A

Surface cleaning
Barriers that allow unidirectional flow
Physical separation from non sterile sites

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

What are some examples of sterile sites?

A 
Lower RT
Upper GT
Spinal cord
Meninges
Middle Ear
Urinary Tract
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Coagulase Negative Staphylococci
Staphylococcus aureus
Propionibacterium acnes
Corynebacterium spp

Are examples of what?

A

Normal skin flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is the skin difficult to colonise?

A

Variable temp
Dry
Aerobic environment
Nutrient Poor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Viridians
Oral strep
Anaerobes gram -ve and +ve
Candida spp

Are examples of what?

A

Normal mouth flora

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are cavities in the mouth easy to colonise?

A

Constant temp
Moist
Rich nutrient source
Few physical challenges

19
Q

What organisms make up the normal nasopharyngeal flora?

A

Same as skin flora

20
Q

What organisms make up the normal flora of the pharynx?

A 
S. pyogenes
H. influenza
S. pneumonia
N. meningitides
S. aureus
M. catarhallis
21
Q

When does the flora of the vagina change?

A

Puberty

Addition of Lactobacillus spp to the normal skin flora

22
Q

What does lactobacillus spp do?

A

Ferment glycogen and maintain a pH of around 3

23
Q

What is the make up of flora in the stomach?

A

Low pH inhibits bacterial growth
Acid tolerant lactobacilli
H. pylori

24
Q

What happens to the amount of organisms as you descend through the GI?

A

They increase in number

25
Q

What are some characteristics of the flora of the large intestine?

A

Mostly anaerobes
Some aerobic bacteria such as enteric gram -ve bacilli
Milleri spp. also present

26
Q

What are the benefits of normal flora?

A

Synthesis and excretion of vitamins
Colonisation resistance
Induction of cross reactive antibodies

27
Q

Define pathogenicity

A

The capacity of an organism to cause infection

28
Q

What key factors does an organism require in order to cause an infection?

A

Transmissibility
Establishment in or on a host
Harmful effects
Persistence

29
Q

What are the 6 stages of infection?

A 
Pathogenic organism
Reservoir
Exit
Transmission
Entry
Susceptible host
30
Q

What is virulence?

A

The degree to which an organism can cause disease

31
Q

What is infectivity?

A

The ability of an organism to become established on or in a host via a microbial ligand or host cell receptor

32
Q

What is the virulence factor for bacteria?

A

Endotoxins

33
Q

What are some characteristics of endotoxins?

A

Components of the gram negative cell wall
Released from damaged/dead cells
Active component is lipopolysaccharide
Induce a range of uncontrolled host cell responses after binding to host cell receptors

34
Q

What is the host response to endotoxins?

A 
Systemic inflammatory response
Uncontrolled T Lymph response
Cytokine release
DIC
Cardiac and renal failure
35
Q

Botulism is a type of which virulence factor?

A

Exotoxin

36
Q

What is the mechanism of action of Clostridium botulinum?

A

Blocks ACh receptor and release of ACh causing a neuromuscular blocking effect

37
Q

What is the clinical presentation of botulism?

A 
Diplopia
Dysphagia
Dysarthria
Dry mouth
Death due to respiratory failure
38
Q

What exotoxin is produced in tetanus?

A

tetanospasmin

39
Q

What is the mechanism of action in tetanus?

A

Tetanospasmin binds to nerve synapses and inhibits the release of inhibitory neurotransmitters in the CNS causing a loss of inhibitory action on motor and autonomic neurons

40
Q

Cholera, diphtheria, C.diff, whooping cough - are all examples of what?

A

Exotoxin mediated infections

41
Q

Which virulence factors cause the following?

Break down of connective tissue
Inactivation of complement component C5a
Lyse blood cells

A

Hyaluronidase and streptokinase
C5a peptidase
Streptolycin -O and -H

42
Q

How does S. progenies evade the immune system?

A

M-protein binds fibrinogen and masks the bacterial surface which blocks complement binding and opsonisation

43
Q

This organism has a polysaccharide capsule which inhibits opsonisation and therefore phagocytosis

A

S.Pneumonia

Essential Medical Science (UoL, Medicine) (9 decks)

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