Bacterial Pathogenesis Redemption Deck

Question 1

what are the three main mechanisms of pathogenicity?

Answer 1

establish infection

avoiding defenses

damage to the host (disease)

Question 2

how to establish infection? (3)

Answer 2

AIM: adhere, invade, multiply

adhere, multiply, invade by breaching barriers

Question 3

how to avoid defenses? (3)

Answer 3

HAAP

hide, avoid phagocytosis, avoid antibodies

Question 4

how to cause damage to the host? (2)

Answer 4

directly, via toxins or cell damage, or indirectly, via the immune system

Question 5

what are five ways pathogens can adhere to cells?

Answer 5

surface proteins

capsules

slime layers

biofilms

causing changes in host cells

Question 6

Type III secretion systems, aka

Answer 6

Injectisomes, aka

Question 7

What do type three secretion systems do?

Answer 7

deliver effector proteins to induce changes in the host cell

Question 8

what special molecules do pili/cell surfaces use to bind to host cell receptors?

Answer 8

adhesins

Question 9

what are adhesins?

Answer 9

special molecules that pili/cell surfaces use to bind to host cell receptors

Question 10

what are three mechanisms that pathogens use to establish infection?

Answer 10

penetrating skin (cuts, bites, wounds)

directed uptake by an epithelial cell (membrane ruffling by GN bacteria)

exploiting antigen-sampling processes (Shigella uses M cells to gain entry into host tissue, move cell to cell)

Question 11

what are the four main ways that pathogens avoid host defenses?

Answer 11

hide the MAP from the host.

1. avoid antibodies
2. hide within a host cell
3. avoid MACs by complement proteins
4. avoid destruction by phagocytes

Question 12

how do pathogens “avoid antibodies”? (4)

Answer 12

• shed antigens
• produce IgA protease
• change antigens
• mimic self (invisibility cloak)

Question 13

what is the term for shedding antigens? what’s an example of that?

Answer 13

phase variation. pili.

Question 14

what is the term for changing antigens?

Answer 14

antigenic variation

Question 15

what is an example of a pathogen mimicking self (invisibility cloak)

Answer 15

LOS of Neisseria gono

Question 16

what does it mean to be serum resistant? what’s one type of cell that is serum resistant?

Answer 16

cannot be killed by MACs (membrane attack complexes). some gram negative cells.

Question 17

how do some pathogens avoid MACs by complement proteins?

Answer 17

hijack host regulatory protein and prevent MAC formation

Question 18

what are three general ways that pathogens avoid destruction by phagocytes?

Answer 18

the same way I did in the Institute today: prevent encounters, avoid recognition, and if you have to talk to him, just survive the convo.

1. prevent encounters with phagocytes
2. avoid recognition and attachment
3. survive within phagocytes.

Question 19

what are two structures that help in preventing encounters with phagocytes?

Answer 19

• C5a peptidase
• Cytolytic toxins

Question 20

what are three structures that help in avoiding recognition and attachment?

Answer 20

• capsules
• M protein
• Fc receptors

Question 21

what are three mechanisms to survive within the phagocytes?

Answer 21

• escape from the phagosome
• prevent phagosome-lysosome fusion
• survive within the phagosome

Question 22

if a pathogen causes disease, they are causing direct damage to the host. what are the four mechanisms of causing disease?

Answer 22

• Production of toxins that are then ingested
• Colonization of mucous membrane, followed by toxin production
• Invasion of host tissues
• Invasion of host tissues, hollowed by toxin production

Question 23

what are three types of exotoxins?

Answer 23

1. A-B toxins
2. membrane-damaging toxins
3. superantigens

Question 24

why wouldn’t you use a vaccine on an endotoxin?

Answer 24

they are lipid based

Question 25

Injectisomes, aka

Answer 25

Type III secretion systems, aka

Question 26

1. A-B toxins
2. membrane-damaging toxins
3. superantigens

Answer 26

what are three types of exotoxins?