Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MicroImmuno > Pathogenesis and Host Resistance > Flashcards

Pathogenesis and Host Resistance Flashcards

1
Q

Define pathogen.

A

Organism that typically causes disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define opportunistic pathogen.

A

Organism that typically causes disease in immunocompromised people.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define nonpathogen.

A

Organism that typically does not cause disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define avirulent organism.

A

Organism that does not cause disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define virulence.

A

Quantitative measure of pathogenicity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does ID50 mean in terms of virulence? What is the amount needed for shigella? For salmonella?

A

The number of organisms needed to infect 50% of hosts

Shigella <100; Salmonella~10^5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define infection.

A

Pathogenic organism present and multiplying in host.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Define infectious disease.

A

Pathogenic organism causes damage to host or host tissues.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What’s the difference between a communicable disease and a contagious disease?

A

Communicable disease is transmissible by infection directly or through the agency of a vector while a contagious disease is a very communicable disease (spreads directly or indirectly).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What outweighs what in a host when infectious diseases occur?

A

When the infectious organism outweighs the host defenses
Dose, Virulence > Innate, Acquired defenses

???

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What’s the difference between local infection and systemic infection?

A

Local occurs in a certain area of the host, while systemic occurs across all organs/systems of the host.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What’s the difference between acute and chronic infections?

A

Acute is abrupt and short lived; chronic is long lived.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What’s the difference between subclinical infections and asymptomatic infections?

A

Subclinical infections are not apparent by clinical examinations. Asymptomatic Infections do not show any symptoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define latent infections.

A

An asymptomatic infection capable of manifesting symptoms under particular circumstances or if activated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the stages of pathogenesis?

A
  1. Transmission
  2. Evasion of primary host defenses
  3. Adherence/Colonization
  4. Disease symptoms caused by invasion or toxin production
  5. Host response (during 3 & 4)
  6. Progression or resolution of infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What’s the difference between an exogenous infection and an endogenous infection?

A

Exogenous is transmitted by an external source. Endogenous is transmitted by one’s own normal flora.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are 3 ways for exogenous infections for humans?

A

From other humans, animals and organisms in the environment.

Soil – Clostridium
Water – Legionella

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the term for new infections often found in patients after being admitted to hospitals?

A

Nosocomial infections.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are a few ways for direct human to human infections?

A

Sexual contact (HIV, syphilis)
Skin/urine/blood
Tranplacental (rubella, cytomegalovirus)
At birth (Hep. B, HIV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How about indirect human to human infections?

A

Airborne respiratory droplets.
Fecal contamination of food/water.
Vectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define reservoir.

A

Host/carrier that harbors pathogenic organisms without injury to self and serves as a source from which others can be infected.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define vector.

A

The mechanism that transmits pathogenic organisms FROM reservoir TO source.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In Malaria (indirect human to human) what is the vector and what is the reservoir?

A

Humans are the reservoir.

Mosquitos are the vectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In what way is infection directly transmitted from animal to humans?

A

Biting.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

In what way is infection indirectly transmitted from animal to humans?

A

Airborne respiratory droplets.
Fecal contamination of food/water.
Vectors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In Bubonic plague, reservoir + vector?

A

Rats are reservoir. Fleas are vectors.

27
Q

In Lyme disease, reservoir + vector?

A

Mice are reservoir. Ticks are vectors.

28
Q

During the colonization/adherence stage, organisms must evade what 2 types of immune defenses?

A

Innate (non-specific early defense with no memory) and acquired defenses (highly specific, delayed with long term memory).

29
Q

What physical barriers act as our innate defense?

A

Skin, ciliated mucous membranes, stomach pH and normal flora.

30
Q

What cellular components act as our innate defense?

A

Phagocytes, complements, lysozymes.

31
Q

List a few ways that organisms evade our immune defenses.

A
  1. IgA protease
  2. Surface structures that prevent phagocytosis (capsules, protein A, M protein)
  3. Antigenic Variation
  4. Intracellular state
  5. Colonization of foreign bodies (artificial heart valves)
32
Q

What do organisms need to do first in order to multiply and cause disease?

A

They need to adhere to the host’s cell surfaces.

33
Q

How do organisms attach to cell surfaces?

A

Adherence factors such as pili, cell wall components (teichoic acid), slime layer (glycocalyx) in Strep. Mutans.

34
Q

What happens after adherence, basically how do organisms cause disease?

A
  1. Inflammation (organs presence and produce enzymes that degrade tissue – collagenase, hyaluronidase, coagulase, lecithinase, hemolysins)
  2. Toxin production (exo/endotoxin) and
  3. Immunopathogenesis (Ab’s against infectious agent damage normal tissue)
35
Q

What organism causes Gas Gangrene? How does it cause this?

A

Clostridium perfringens, produces many enzymes (proteases, lipases); lecithinase, degrades the host cell membranes.

36
Q

What are the pros and cons of acute inflammation?

A

Defensive response that fundamentally protects host, but can be responsible for clinical manifestations of an infection.

37
Q

What initiates the inflammatory response in acute inflammation?

A

Presence of foreign bodies including microorganisms.

38
Q

What cells are involved in acute inflammation?

A

Macrophages and neutrophils (PMNs).

39
Q

What mediators are involved in acute inflammation?

A

Cytokines, chemokines, histamine, bradykinin.

40
Q

What are the two types of toxins produced by bacteria? What type of bacteria (gram stain) produces each toxin?

A

Endotoxin: Part of cell wall of gram (-) bacteria with LPS in outer membrane

Exotoxin: Produced by both gram (+/-) and secretes proteins

41
Q

Which toxin has a high toxicity

A

Exotoxin

42
Q

Are there any vaccines for endotoxins?

A

No

43
Q

What are the effects of endotoxin?

A 
IL-1 Fever.
Tumor Necrosis Factor.
Nitric Oxide (vasodilation, hypotension).
Hageman Factor (DIC). 
Complement (alternative pathway).
44
Q

What toxin and mediator causes septic shock? What organism? What’s the fatality rate? Cases/year?

A

Endotoxin by Tumor Necrosis Factor. Meningococcal meningitis; 30-50% fatality; 500,000 cases/year

45
Q

How do exotoxins produce their toxicity?

A

Through proteins (polypeptides) consisting of 2 subunits (A and B).

46
Q

Through proteins (polypeptides) consisting of 2 subunits (A and B).

A

A: Toxic activity
B: Binds to cell target, delivers toxin

47
Q

Through what process do exotoxins act?

A

ADP-ribosylation of target protein

48
Q

What is an exotoxin of neurological cells called? Of the stomach cells? Of skin cells?

A 
Neurological = Neurotoxins
Stomach = Enterotoxins
Skin = Exfoliatins
49
Q

What type of vaccine is there for exotoxins?

A

Toxoid vaccine

50
Q

What causes choleragen?

A

Vibrio cholera

51
Q

What causes toxic shock syndrome toxin?

A

Staphylococcus aureus

52
Q

What causes tetanus toxin?

A

Clostridium tetani

53
Q

What causes botulinum toxin?

A

Clostridium botulinum

54
Q

What causes diphtheria toxin?

A

Corynebacterium diphtheriae

55
Q

How does acute rheumatic fever occur?

A

Antibodies that cross react with joint, heart, and brain tissues.

56
Q

How does acute glomerulonephritis occur?

A

Antigen-antibody complexes form that activate complement and cause inflammation.

57
Q

What are the stages of an infectious disease?

A
  1. Incubation period - time between acquisition of organism and the beginning of symptoms.
  2. Prodrome period - time of non-specific symptoms such as fever, malaise, anorexia.
  3. Specific illness period - characteristic signs, symptoms of disease.
  4. Recovery period - illness abates
58
Q

Name Koch’s postulates

A
  1. The organism must be isolated from every patient who has the disease.
  2. The organism must be grown in pure culture.
  3. The pure organism must cause disease in a healthy susceptible animal.
  4. The organism must be recovered from the inoculated animal.
59
Q

Which postulates are problematic with today’s knowledge of science?

A

Some organisms can’t be grown in pure culture, and did the organism actually cause the disease?

60
Q

What are the two types of vaccinations? Describe each.

A

Active: developed because the organisms immune system has produced antibodies after an infection or inoculation

Passive: Immunity acquired by the transfer from another animal of antibody or sensitized lymphocytes

61
Q

What are 3 ways to induce active immunization?

A
  1. Toxoid vaccines (Tetanus, diphtheria)
  2. Subunit vaccines (Capsular - H. influenzae, S. pneumoniae)
  3. Whole bacteria - not in use much, original pertussis vaccine
62
Q

How is passive immunization produced?

A

Neutralize toxins

63
Q

What are 3 major strategies for disease prevention?

A
  1. Public health sanitation.
  2. Immunization.
  3. Sterilization/antisepsis.

MicroImmuno (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions