Principles Of Infection I

Question 1

What are microorganisms?

Answer 1

Bacteria, virus, fungi that are too small to be seen by the naked eye
They can exist as a single cell or in a colony of cells

Question 2

Classifications of microorganisms.

Answer 2

Helminths = Animals 
Fungi = Fungi 
Algae = Algae
Protozoa = Protozoa 
Archer = crenachaeota

Question 3

What is the definition of Infection?

Answer 3

A transmissible, communicable form of disease which is caused by microorganisms (Including Viruses)

Question 4

What are the five stages of infection?

Answer 4

Incubation
Prodromal 
Illness
Decline 
Convalescence

Question 5

Give examples of different sub-types of infection

Answer 5

Viral
Fungal
Parasitic
Bacterial

Question 6

What cell type is a bacterial cell?

Answer 6

Eukaryotic

Question 7

What type of infection is easier to treat/Kill with antibiotics?

Answer 7

Gram positive

Question 8

What are the key features of bacterial cells?

Answer 8

There is no nucleus
They have a peptidogyclan cell wall.
Have circular DNA
Lack of membrane bound organelles

Question 9

What are the two gram stains that can be achieved?

Answer 9

Gram positive

Gram negative

Question 10

What is the innate immune system?

Answer 10

Non-specific defence system which can act quickly; within minutes and hours
Present from birth
innate immune responses are the first line of defence​ against invading pathogens.

Question 11

What are anatomical barriers?

Answer 11

Tough/ intact barriers which prevent entry and colonisation of many microbes

Question 12

List Examples of anatomical barriers

Answer 12

Skin
Mucous membranes
Bony encasements

Question 13

What are antimicrobial peptides?

Answer 13

Very small and can kill bacteria directly

Question 14

What is the first line of defence of all multicellular organisms?

Answer 14

Antimicrobial peptides

Question 15

What are the different types of white blood cells

Answer 15

Neutrophils
Basophils 
Eosinophils 
Monocytes 
Lymphocytes

Question 16

What is the mechanism of the innate immune system?

Answer 16

Skin
Chemicals in the blood
Immune system. cells attack foreign cells in the body

Question 17

What is the adaptive immune system?

Answer 17

Highly specialised systems that take longer to produce (time) to produce antigens within the body.

Question 18

Give some examples of antimicrobial peptides?

Answer 18

Cationic peptides
noncationic peptides
Glycopeptide vancomycin

Question 19

What are cationic peptides?

Answer 19

Short peptides secreted by the immune/ epithelial cells

Question 20

What cells are involves in cell mediated response?

Answer 20

T - cells

Question 21

What cells does the humeral response involve?

Answer 21

Antimicrobial peptides, antibodies

B cells/ antibodies

Question 22

What are the 2 responses antibodies are involved in?

Answer 22

Primary & secondary response

Question 23

What does the primary response involve?

Answer 23

Memory cells are low in levels, slower response

Question 24

What does the secondary response involve?

Answer 24

Memory cells are high in levels

Much faster response

Question 25

What is human microbiota?

Answer 25

All microorganisms living in and on a human

Question 26

What is a microbiome?

Answer 26

All genes of all microbiota

Question 27

List infections caused by bacterial cells.

Answer 27

Cholera Tuberculosis Syphilis Bacterial meningitis

Question 28

What is the difference between gram negative & gram positive stains

Answer 28

Gram positive keeps the purple stain | Gram negative loses the purple stain (turns pink)

Question 29

Why does the gram negative cell lose the purple stain?

Answer 29

Due to the presence of the peptidoglycan cell wall

Question 30

What is the structure of a gram negative cell?

Answer 30

Thin layers of peptidoglycan walls but there are two; outer and inner lipid membranes which makes it harder to penetrate the cell wall

Question 31

What is the structure of gram positive cell

Answer 31

Thick layer of peptidoglycan wall but there is no outer lipid membrane Has one inner plasma membrane and this can be penetrated easily by antibiotics

Question 32

What is easier to kill with antibiotics?

Answer 32

Gram positive

Question 33

What are the main bacterial shapes?

Answer 33

Cocci - spherical bacteria Bacilli - rod shaped bacteria Spirilla - spiral shaped bacteria Vibrio - curved bacteria

Question 34

What are the three main types of bacteria in regards to oxygen?

Answer 34

Faculatative anaerobes Anaerobic organisms Aerobic organisms

Question 35

What are the stages of viral reproduction?

Answer 35

``` Attachment Penetration Uncoating Replication of nucleic acid and synthesis of protein coats Assembly Release ```

Question 36

What are the 4 stages of infection?

Answer 36

Transmission Infection Pathogenicity Virulence

Question 37

What is the transmission stage of infection?

Answer 37

Host acquires the organism

Question 38

What is the infection stage of infection?

Answer 38

Organism has to reproduce inside the host

Question 39

What is the pathogenicity stage of infection?

Answer 39

Interacting with the host in a way that causes disease

Question 40

What is the virulence stage of infection?

Answer 40

This is the severity of the disease

Question 41

What are the main factors of virulence?

Answer 41

Adhere to and invade host tissues Evade host defences Proliferate in the host Cause damage = produce toxins

Question 42

What does virulence factors allow to take place?

Answer 42

Enables the host to replicate and spread within a host

Question 43

How do we evade host defences

Answer 43

Can be achieved by entering the bloodstream

Question 44

What is the name given to the production of toxins?

Answer 44

Toxigenicity

Question 45

What is an antigenic drift?

Answer 45

Small changes in viral antigens due to point mutations in genes. It makes the virus harder for adaptive immune system to recognise.

Question 46

What is antigenic shift?

Answer 46

Major changes in viral antigens due to gene reassortment. | Makes virus much harder for adaptive immune system to recognise.

Question 47

How do virulence factors arise?

Answer 47

Encoded and translated for genes in chromosomal DNA

Question 48

State some infections due to virus.

Answer 48

Flu Smallpox Common cold HIV/AIDS