Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Microbes and humans > Flashcards

Microbes and humans Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q
  1. Microflora/microbiota

2. Microbiome

A
  1. everyday microbes of a person
  2. collective genomes of all microorganisms that live on a person

(used interchangeably)

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

Microbes colonize human surfaces

3 points

A
  1. in contact with the ‘outside world’ (respiratory tract, nose, mouth, gut, skin, gut lumen)
  2. In healthy people microbes don’t enter internal tissues. Inside of bodies relativley sterile
  3. If microbes enter beyond surface = possible disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Microbes at birth

4 points

A
  1. Babies born relatively sterile (some bacteria may be passed from placenta)
  2. Hours after birth gut colonised by microbes from mothers, nurses, bedding etc. [some picked up from birthing canal]
  3. Microbial community established by 3 yrs old (adult like) [diversity is increasing from birth to 3 yrs]
  4. Established gut microbiota contributes to overall health, gut physiology and immune system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The skin microbiota

2 points

A
  1. Average human skin 2m2

2. Many of 1012 bacteria on skin are commensals or transient [not long lasting, get washed off] microbes

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

Skin is unsuitable for many microbes

5 points

A
  1. pH slightly acidic
  2. High concentration of sodium chloride
  3. Often very dry
  4. Contains antimicrobial properties
  5. Variable temperatures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Mouth Microbiota

2 points

A 
1. Good environment
Lots of water 
Lots of nutrients 
Neutral pH
Stable optimal temperature
  1. However
    Bacteria must adhere/attach strongly to gums and teeth or they will be washed away

Tolerate antimicrobial properties of saliva e.g. lysozyme

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

Microbiota

4 points

A
  1. linked with various disesases, diabetes, IBD, obesity
  2. Involved in development of immune system. Dysbiosis [microbiota isnt healthy] is linked to allergies
  3. 2 main phyla - firmicutes & bacteroidetes [which break down indigestible polysaccharides]
  4. Gut microbiome has large capacity for degrading complex carbohydrates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Human Pathogens and disease

4 points

A
  1. Human associated microorganisms mostly commensals benefit but don’t affect or mutualists both benefit
  2. Some may cause harm - disease
  3. Microbes (bacteria fungi, viruses) that cause disease called pathogens (pathos =greek for suffering) larger organism is host
  4. Opportunistic pathogens - microbes that become pathogens in compromised host (e.g. open wound, trauma, cancer, impaired immune system, antibiotics)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Disease

A

An injury to a host organism, caused by a pathogen or other factor, that affects host function

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

Pathogenicity

A

The ability to cause disease

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

Virulence

A

The severity/extent of disease

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

Infection

A

Refers to the multiplication of a pathogen in a host

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

Vector

A

Another organism that transfers the pathogen to the host (eg. ticks, mosquitoes)

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

Endemic

A

A disease that is common to a particular area

eg. Malaria in endemic in some parts of Africa

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

Epidemic

A

when the disease occurs higher than expected in a localised area over a short period of time (eg. Seasonal Flu in Western world, Ebola in Africa 2014)

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

Epidemic –Pandemic

A

a epidemic that has spread over a very large area over a longer period of time (small pox, tuberculosis, black death, AIDS is currently pandemic)

17
Q

Human pathogen 3 examples

A
  1. Fungal - skin disease - dermatophyte
  2. Bacterial - food poisoning - Ecoli 0157
  3. Virus - haemorrhagic fever - ebola
18
Q

Fungal dermatophytes

4 points

A
  1. Common fungal pathogens
  2. Grow dead skin cells and nails
  3. Conditions such as ring worm, athletes foot
  4. Several species of dermatophytes cause similar symptoms
19
Q

Fungal dermatophytes - ring worm

5 points

A
  1. Feed on outer non living layer of epidermis [skin]
  2. Like other fungi they are saprotrophs feeds on/derives nourishment from decaying organic matter
  3. Secrete proteases onto skin to digest keratin (keritinase)
  4. Metabolic by-products cause irritation and inflammation = red, itchy areas
  5. Grow from point of inoculation active hyphae form growing ring
20
Q

bacterial pathogens
E.Coli 0157
8 points

A
  1. Some strains aquired virulence factors that make them pathogenic [aquired from other sources]
  2. E.coli food posioning usually due to strain E. coli 0157 (outbreaks in resteraunts, kids nurseries etc.)
  3. E.coli (EHEC) can colonise cattle without causing infection (asymptomatic no symptoms). Cattle is likely reservoir
  4. Cattle manure on salads [not washed appropriately] undercooked beef common sources
  5. EHEC attaches strongly to epithelial cells of gut [has to get through other microbes and mucus layer that sits on top of epithelial cells]
  6. Stays on outside of epithelial gut & injects its own receprot through type 3 secretion
  7. Other injected proteins (effector proteins) disrupt gut physiology =diarrhoea & vomiting
  8. Secrete Shiga toxins inhibit protein synthesis and target kidney and blood vessels [serious infection]
21
Q

Ebola Virus

3 points

A
  1. Cause by Ebola filovirus
  2. Endemic in african countries
  3. Recent epidemic in africa due to highly virulent strain = 1000s deaths
22
Q

Ebola Virus - signs and symptoms

A
  1. Patients may suffer from ‘post-Ebola syndrome’ can last for yrs as virus can hide in body [can reoccur]
23
Q

Ebola Virus Genome codes for 7 proteins

A
  1. Polymerase L plus VP35 - replicates viral RNA in cytoplasm
  2. Nucleoprotein - encapsulates RNA
  3. VP30 - transcription factor
  4. Glycoprotein (GP) - thought to be responsible for attachment to host cells
  5. Viral proteins VP24, Matric VP40 and GP associate with cell membrane

After RNA coated by nucleoprotein buds out through cell membrane gaining outer lipoprotein coat from cell [hides from immune system

24
Q

How ebola causes disease

4 points

A
  1. Enters body through mucosal surfaces (eye, mouth, gut etc.) [human, animal contact]
  2. Targets most tissues including immune cells - inhibits immune system
  3. Quickly travels through body - replicates quickly \
  4. Destroys tissues by interfering with cell-cell adhesion of endothelial cells liing blood vessels > massive internal bleeding (Haemorrhagic fever [fever & lots of bleeding]
25
Q

Ebola a Zoonotic disease

5 points

A
  1. Ebola is a zoonotic disease can be transmitted from animals to man [key]
  2. Reservoir host unlikely to be monkey/ape as often die
  3. Bats appear to be natural resevoir as can be carriers without disease (asymptomatic)
  4. Transmission between human to human - fluid secretions

Microbiology (13 decks)

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