Exam 4 Chapter 15

Question 1

virulence def.

Answer 1

pathogen’s disease-causing ability

Question 2

T/F
High Virulency = high pathogenicity

Answer 2

True

Question 3

virulence factors def

Answer 3

the attributes of a microbe that enable it to cause disease (aka virulence determinants)

Question 4

T/F
immune system does not need to be completely overcome

Answer 4

True
Only long enough to multiply and leave host

Question 5

(4) ways a pathogen causes disease

the four steps

Answer 5

1) Production of toxins are ingested
2) Colonization of surface of host followed by toxin production
3) Invasion of host tissue
4) Invasion of host tissue followed by toxin production

ingestion/colonization/invade/invade+toxins

Question 6

Toxin Ingestion virulence factor

leads to what?

Answer 6

Toxin production

Question 7

Colonization of surface host followed by toxin production virulence factor are mechanisms that allow what?

Answer 7

attachment to host cells AND to deliver toxin

Question 8

Invasion of host tissues virulence factors (3)

steps microbe will take in invading

Answer 8

-Penetration of barriers and multiply in tissues
- Attach to host cells
-Avoid destruction by macrophages

ex.salmonella

Question 9

Adherence proteins on bacterial cells are called:

Answer 9

adhesins (tip of pili or fimbriae)

Question 10

alternative method for adhesion

Answer 10

slime layers or capsules

Question 11

secretory antibodies (IgA) func.

Answer 11

bind to adhesins to prevent attachment

Question 12

siderophores func.

Answer 12

iron-binding molecules; compete with host proteins for circulating iron

Question 13

penetration of mucous membranes mechanisms (2)

Answer 13

Directed uptake
Changes in surface molecules via antigen variation

Question 14

Directed uptake func.

Answer 14

deliver molecules directly into host cell

used by gram negative bacteria

Question 15

antigen-sampling: M cells act as a

Answer 15

a conduit between intestinal lumen and lymphoid tissue

Question 16

actin tails

Answer 16

pathogen ability to propel using actin tails

Question 17

Avoiding Complement Proteins

complement proteins act in a system to produce three outcomes:

Answer 17

inflammation
lysis of foreign cells (MAC)
Opsonization

Question 18

T/F
Gram-neg bacteria are susceptible to the membrane-attack complex

Answer 18

True, outer membrane serves as a target

Question 19

How can pathogens avoid the membrane attack complex (MAC)

Answer 19

by binding the host’s own regulatory proteins

Question 20

preventing opsonization: capsule

inactivates complement how?

Answer 20

capsule proteins bind to complement regulatory proteins = inactive complement

Question 21

preventing opsonization

: M protein func.

binds to what to inactivate complement proteins?

Answer 21

binds to complement regulatory proteins

Question 22

preventing opsonization:

what role do Fc receptors play in binding of antibodies?

Answer 22

region where antibodies can attach to pathogen in opposite direction

Question 23

Surviving within the Phagocyte

mechanisms include:

mechanisms used to survive within phagocyte (3)

escape/prevent/survive

Answer 23

escape from phagosome
preventing phagosome-lysosome fusion
surviving within phagolysosome

Question 24

Surviving within the Phagocyte: mechanism:

escaping from phagosomes allows bacteria to do what?

Answer 24

bacteria to multiply in the cytoplasm

Question 25

# Surviving within the Phagocyte: mechanism: surviving within phagolysosome allows the pathogen to do **delay** what?

Answer 25

Delay fusion(of phagolysosome) to allow organism time to equip itself for growth/survival within phagosome

Question 26

# Avoiding Antibodies mechanisms (3) | Cleaves what bonds? Antigenic variation = how disguise self?

Answer 26

Cleave Peptide bonds via IgA protease Change surface molecules viaAntigenic variation mimicking host molecules

Question 27

# Avoiding Antibodies antigenic variation func.

Answer 27

alteration of surface molecules (antigens)>>antibody >>allows bacteria to stay ahead of antibody production

Question 28

# Avoiding Antibodies mimicking host molecules func.

Answer 28

pathogens can cover themselves with molecules that resemble normal host "self" molecules

Question 29

# Damage to the Host in order to cause disease, the pathogen must cause what?

Answer 29

damage

Question 30

# Damage to the Host damage facilitiates what once it happens? | coughing/diarrhea why?

Answer 30

dispersal of organisms | vibrio cholerae causes diarrhea ## Footnote bordetella petussis causes coughing

Question 31

# Exotoxins exotoxins are secreted by :

Answer 31

bacterium | or leak into surrounding fluids following cell lysis

Question 32

exotoxins are made by:

Answer 32

protein ## Footnote makes them heat labile; and good toxoids

Question 33

xFunctional categories of exotoxins (** know examples**)

Answer 33

Neurotoxins Enterotoxins Cytotoxins

Question 34

Neurotoxins damage what? | example?

Answer 34

damage to nervous system >>ex. tetanus toxin

Question 35

Major symptom of a neurotoxin

Answer 35

paralysis

Question 36

Enterotoxins def | example? (bloody diarrhea)

Answer 36

Damage to intestines and tissues of digestive tract >>ex. shiga toxin -> bloody diarrhea

Question 37

Cytotoxins def/func

Answer 37

Damage to various cells; inteference with cell function or lysis >>ex. trachael cytotoxin

Question 38

Exotoxins STRUCTURAL categories

Answer 38

A-B Toxins Membrane-damaging toxins Superantigens

Question 39

Two parts of A-B toxins

Answer 39

A and B

Question 40

A-Toxin

Answer 40

A subunit is the toxic or active part

Question 41

B-Toxin

Answer 41

B subunit binds to specific receptors on cells ex>> shiga toxin | the receptor

Question 42

Membrane-Damaging Toxins func.

Answer 42

disrupts plasma membranes | aka hemolysins or cytolysins

Question 43

phospholipases func.

Answer 43

remove the polar head of phospholipids >>Destabilizes the membrane causing it to rupture ex. C. perfrinigens

Question 44

superantigens func.

Answer 44

cause over-stimulation of helper T cells >>stimulates 1 in 5 T cells versus 1 in 10,000 T cells

Question 45

Helper T cells release _________ that induce immune response.

Answer 45

cytokines

Question 46

toxic shock syndrome def.

Answer 46

systemic shock leading to the failure or organ systems, circulatory collapse and death

Question 47

Endotoxins are all gram-______ cells

Answer 47

negative

Question 48

# Endotoxins T/F Endotoxins are heat stable

Answer 48

true; not suitable for use as toxoids

Question 49

# Endotoxins what lipid (a/b) is responsible for toxic properties?

Answer 49

Lipid A

Question 50

# Endotoxins what toxin is responsible for septic shock?

Answer 50

endotoxins; endotoxic shock

Question 51

# Endotoxins other bacterial ____ ____ components can act as endotoxins

Answer 51

cell wall

Question 52

endotoxic shock symptoms

Answer 52

fever, drop in blood pressure

Question 53

How are viruses taken up into cells once attached?

Answer 53

receptor mediated endocytosis or membrane fusion

Question 54

# Avoiding immune responses inteferon func.

Answer 54

alter regulatory responses of cells in event of viral infection; limits viral replication

Question 55

how viruses interrupt inteferon inhibition

Answer 55

by encoding specific proteins

Question 56

viruses and host damage: viruses enter the host and then what?

Answer 56

enter, replicate, and burst releasing copies to infect new cells

Question 57

why would a virus block apoptosis?how?

Answer 57

to avoid immune response, blocks p53

Question 58

why would a virus induce apoptosis?

Answer 58

limits inflammatory response and stimulation of immunity

Question 59

apoptosis is regulated by a protein called ____

Answer 59

p53

Question 60

T/F antibodies interact with extracellular viruses only

Answer 60

true; viruses develop mechanisms to directly transfer from one cell to neighbor to avoid antibody exposure

Question 61

syncytium def. | viruses create this why?

Answer 61

virus method to avoid immune response; forces cells to fuse | remains intracellular

Question 62

syncytium vs biofilm

Answer 62

syncytium is a fuse of natural human cells biofilm is a merge of multiple organisms

Question 63

# Viruses can use antibody to enhance infectability what portion does the virus attach to of an antibody

Answer 63

Fc; initiates Fc-mediated uptake of viral-antibody complex by macrophages

Question 64

t/f viruses replicate faster than antibodies

Answer 64

true; can rapidle alter surface antigens

Question 65

# Eukaryotic Pathogenesis: fungi saprophyte def.

Answer 65

an organism that feeds on decaying matter

Question 66

fungi that cause disease are generally:

Answer 66

opportunistic; *candida albicans*

Question 67

most serious fungal infections are caused by

Answer 67

dimorphic fungi

Question 68

how does infection begin in fungal eukaryotic pathogensis

Answer 68

inhalation of airborne spores>>spores lodge in lung tissues

Question 69

T/F spores then live inside macrophages

Answer 69

True; undergo morphological change

Question 70

mycotoxins damage what?

Answer 70

liver

Question 71

eukaryotic parasites main pathogenesis method:

Answer 71

via bite of arthopod

Question 72

what fungal species can enter directly through skin?

Answer 72

*Schistisoma*

Question 73

# Eukaryotic pathogenesis: fungi extent of damage:(3) | ; what kind of damage?

Answer 73

compete for host nutrients blockages of intestines/other organs enzymes digest host tissues