Pathogenesis And Virulence

Question 1

What are the 5 types of symbiotic relationships

Answer 1

Mutualism, amensalism, commenalism, neutralism, parasitism

Question 2

How is either population effected in a mutualism symbiotic relationship

Answer 2

Both populations are benefited

Question 3

How is either population effected in an amensalism symbiotic relationship

Answer 3

One population is harmed and the other is unaffected

Question 4

How is either population effected in a commensalism symbiotic relationship

Answer 4

One benefits the other is unaffected

Question 5

How is either population effected in a neutralism symbiotic relationship

Answer 5

Both are unaffected

Question 6

How is either population effected in a parasitism symbiotic relationship

Answer 6

One benefits and the other is harmed

Question 7

Define pathogenicity

Answer 7

The ability to produce pathologic changes or disease

Question 8

Define pathogen

Answer 8

disease producing microorganism

Question 9

Define Virulence

Answer 9

measure of pathogenicity. Also, involves invasiveness and
pathogenicity

Question 10

Define toxigenicity

Answer 10

ability to produce toxins

Question 11

What ways do foetus acquire normal flora

Answer 11

Mouth and nose populated from birth canal,

• skin populated by transfer from parents/ doctors
• intestine and gut flora develops after first meal

Question 12

What are the differences between primary and opportunity pathogens

Answer 12

• primary causes diseases regardless, whereas opportunistic the disease is caused in compromised hosts

Question 13

What are the 3 main steps in pathogenic bacteria infection

Answer 13

Exposure, adherence, invasion

Question 14

What does the exposure stage of pathogenic bacteria infection include

Answer 14

Direct contact surfer from the environment or vectors

• main entry point is mucous membranes

Question 15

What are the 4 main areas of exposure

Answer 15

Direct contact
From the environment
From vectors
From fomites (inanimate objects)

Question 16

What does the adhesion stage of pathogenic bacteria infection include

Answer 16

Biofilm formation
- adhesins

Question 17

What does the invasion stage of pathogenic bacteria infection include

Answer 17

Production of lytic substances that alter host tissue

• penetration of deeper tissues and continued dissemination

Question 18

What are some main classes of exoenzymes

Answer 18

Nucleases, glycohydrolases, phospholipases, proteases

Question 19

What is the function of glycohydrolases

Answer 19

Degrades hyaluronic acid that cements cells together to promote spreading through tissues

Question 20

What is the function of nucleases

Answer 20

Degrades DNA released by dying cells

Question 21

What is the function of phospholipases

Answer 21

Degrades phospholipid bilayer of host cells

Question 22

What is the function of proteases

Answer 22

Degraded collagen in connective tissue to promote spread

Question 23

What are the main aspects of endotoxins

Answer 23

They’re released on bacteria death
- they’re heat stable

Question 24

What systemic effects are produced by endotoxins

Answer 24

Fevers
- intestinal haemorrage
- inflammation
- stimulates the immune system

Question 25

What are the main aspects of exotoxins

Answer 25

Soluble - produced within bacteria ( mainly gram positive) - may travel away from the site of infection

Question 26

What are the four types ’ of endotoxins

Answer 26

AB toxins (tetanus, cholera) - site specific (neurotoxins) - membrane disrupting (haemolysin) - superantigens (staphylococcal enterotoxin)

Question 27

What is the composition difference between endotoxins and exotoxins

Answer 27

Endotoxins are lipid A components whereas exotoxins are made of proteins

Question 28

What is the source difference between endotoxins and exotoxins

Answer 28

Endotoxins come from gram negative bacteria whereas exotoxins come from primarily gram positive

Question 29

What is the difference in heat stability between endotoxins and exotoxins

Answer 29

Endotoxins are heat stable whereas exotoxins are more heat liable

Question 30

What is the difference in the effect on hosts between endotoxins and exotoxins

Answer 30

Endotoxins - General systemic symptoms of inflammation and fever Exotoxins - specific damage to cells dependant upon receptor mediated targeting of cells

Question 31

What is the difference in LD50 between endotoxins and exotoxins

Answer 31

. Endotoxins are high whereas exotoxins are low

Question 32

What are the 3 types of pathogen multiplication

Answer 32

Local, focal, systemic

Question 33

What is local pathogen multiplication

Answer 33

- small area near entry site - extensive tissue damage but still localised

Question 34

What is focal pathogen multiplication

Answer 34

Spreads to a secondary location / which leads to a secondary infection

Question 35

What is systemic pathogen multiplication

Answer 35

Spreads throughout the body

Question 36

What are the main characteristics of diseases

Answer 36

signs (objective) - body temp 98.2f - heart rate 60-100 - blood pressure 90/60 and 120/80 Symptoms - subjective Nausea, loss of appetite

Question 37

What are the main classifications of diseases

Answer 37

Infectious Iatrogenic Nosocomial Zoonotic Non communicable Non infectious

Question 38

What are the five periods of disease

Answer 38

Incubation, prodromal, illness, decline, convalescence

Question 39

Do incubation periods have a variable length

Answer 39

Yes

Question 40

What are the features of the incubation period

Answer 40

No signs or symptoms Variable length

Question 41

What are the features of the prodromal period

Answer 41

- Multiplication continues - common signs + symptoms ( too general to diagnose a specific disease

Question 42

What are the features of the illness period

Answer 42

- Very severe - most evident - lack of immune response

Question 43

What are the features of the decline period

Answer 43

- decrease in the number of pathogens - decrease in signs and symptoms - potential to acquire secondary infection

Question 44

What are the features of the convalescence period

Answer 44

- Patient recovers - tissue repair leads to normal function - length of time depends on damage severity, nature of pathogen, and the site of infection

Question 45

During which periods are infectious diseases contagions

Answer 45

All 5

Question 46

What is acute infection

Answer 46

- Symptoms develop quickly - brief typically resolves in less than 6 months

Question 47

What is chronic infection

Answer 47

Slow onset of symptoms and can worsen over time - persists beyond 6 months

Question 48

Which membrane serves as the main portal of entry for pathogens

Answer 48

Mucous

Question 49

In which disease period does the patient start to get better

Answer 49

Convalescence

Question 50

What is the name given to infections/diseases acquired from the hospital

Answer 50

Nosocomial

Question 51

What are exotoxins primarily made up of

Answer 51

Proteins

Question 52

Lipid A is a type of what toxin

Answer 52

Endotoxins

Question 53

Tetanus toxin prevents the release of what?

Answer 53

Acetylcholine

Question 54

Which toxin lyses red blood cells

Answer 54

Haemolysins

Question 55

What is the name of a disease that’s contracted due to a medical procedure

Answer 55

Latrogenic

Question 56

What is the measure of pathogenicity

Answer 56

Virulence

Question 57

What type of infection develops quickly

Answer 57

Acute

Question 58

Toxic shock is the most characterised……

Answer 58

Superantigen

Question 59

What enzyme breaks down collagen

Answer 59

Collagenase