pathogens

Question 1

—— have been a major cause of mortality throughout history

Answer 1

infectious diseases

Question 2

pathogen

Answer 2

microbial parasites that are able to cause infections

Question 3

infection

Answer 3

situation in which a microorganism is established and growing in a host, causing damage

Question 4

disease

Answer 4

damage or injury to the host that impairs host fxn

Question 5

pathogenicity

Answer 5

the ability of a parasite to inflict damage to the host

Question 6

virulence

Answer 6

measure of pathogenicity

Question 7

opportunistic pathogen

Answer 7

cause disease only in the absence of normal host resistance. the normal microbiome contains opportunistic pathogens (e.g. if the microbiome of the got enters the urinary tact, it’ll cause disease)

Question 8

different species have different —— properties

Answer 8

virulence

Question 9

a pathogen is usually identified by the:

Answer 9

set of virulence genes that are carried and expressed

Question 10

name and describe the two factors that determine virulence

Answer 10

1) invasiveness: the ability of a microorganisms to become established in the host to overcome the host defensives and to spread in the tissues
2) toxigenicity: the capacity of the microorganism to produce substances known as toxins that damage specific tissues of the host

Question 11

name the different factors used by pathogens to become invasive

Answer 11

• adhesins
• capsule
• enzymes that destroy host tissues
• invasins

Question 12

adhesins

Answer 12

promote specific attachment to the host cell surfaces

- one adresin type is usually able to attach to one r a few cell types, determine the site of colonization

Question 13

——- form loose attachments (adhesins)

while ——- mediate close attachments (adhesins)

Answer 13

fimbriae, pilli,

afrimbial adhesins, surface proteins (not filaments)

Question 14

(T/F)

capsules are produced by some bacterial pathogens

Answer 14

true

Question 15

function of capsules

Answer 15

prevents the pathogen from being destroyed by hist cell immune system (phagocytes, complement, etc)
- also mediates attachment to host cells and to other bacteria

Question 16

capsules are essential virulence factors for :

Answer 16

1) streptococcus pneumoniae

2) haemophilus influenzae

Question 17

(T/F) the capsule is always a virulence factor

Answer 17

false

Question 18

invasiveness is essential to get —- in the tissues and …

Answer 18

depper, consume nutrients

Question 19

pathogens often use —- to enter

Answer 19

wounds

Question 20

through —–, penetration would be easier. explain

Answer 20

mucosa. because there is a single layer of cells with mucous. so if the pathogen manages to destroy the cell they may be Abe to enter or they can enter the cels and grow there

Question 21

loos connective tissue is also called

explain its function and location

Answer 21

extracellular matrix
this is underneath the cell layer. gue around cells made of collagen fibres, hyalouonic acid, fibronection –> structural components that makes it like gue

Question 22

Extracellular enzymes

Answer 22

NOTES

Question 23

invasins

Answer 23

surface proteins, or injected proteins that allow micro-organism to enter cells

• invasion of the host cells, including phagocytes, protect the bacteria; pathogens against the host immune system
• the bacterium grows inside the host ** good source of nutrients

Question 24

—– are major virulence factors of intracellular pathogens

Answer 24

invasins

Question 25

name some pathogens that rely on invasins

Answer 25

• salmonella
• listeria
• chlamydia
• mycobacterium

Question 26

toxigenicity is often a result of —–

Answer 26

invasion

Question 27

extracellular enzymes causing damage are —–

Answer 27

toxins

Question 28

(T/F) toxin production is not always necessary for an organism to be highly virulent. often host’s immune response may result in damage

Answer 28

true

Question 29

bacterial pathogens are associated with 2 distinct categories of diseases, explain them:

Answer 29

1) infectious diseases: result from the pathogen’s growth

2) intoxications: realist from the presence of a specific toxin

Question 30

toxins are divided into 2 categories, explain them:

Answer 30

1) exotoxins: secreted into the surroundings as the bacterial pathogen grows
2) endotoxins: part of the bacterial pathogen