Mechanisms of Bacterial Pathogenesis Flashcards Preview

Unit 1: Micro > Mechanisms of Bacterial Pathogenesis > Flashcards

Flashcards in Mechanisms of Bacterial Pathogenesis Deck (33)
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1
Q

List 3 terms to describe an infection where the host defenses clear the pathogen before any disease symptoms are noted.

A

Asymptomatic, subclinical, or inapparent

2
Q

What term describes an infection that can be passed from host to host?

A

Communicable

3
Q

What term describes a highly communicable infection?

A

Contagious

4
Q

What term describes an infection that comes from the environment, not from a previous host?

A

Noncommunicable

5
Q

Are Botulism and Legionnaires disease examples of communicable, contagious, or noncommunicable infections?

A

Noncommunicable

6
Q

What term describes a host that survives an infection but continues to shed the pathogen?

A

Chronic carrier

7
Q

What term describes an infection where the disease symptoms subside, but the microbe remains in the body and can later reactive?

A

Latent infection

8
Q

What term describes microbes (like viruses) that require host cells to reproduce?

A

Obligate intracellular parasites

9
Q

What term describes microbes that can reproduce either inside or outside of host cells?

A

Facultative intracellular parasites

10
Q

What is the difference between an ID50 and LD50?

A

Infectious dose is the dose at which 50% of people will become sick; Lethal dose is the dose at which 50% of people will die.

11
Q

Which has higher virulence: an ID50 of 30 or an ID50 of 300?

A

30

12
Q

Which has higher virulence: an LD50 of 10 or an LD50 of 100?

A

10

13
Q

A Bacterium that has Mid-Low Pathogenicity and a Low Infectious Dose is most likely what?

A

An opportunistic pathogen

14
Q

Is pH tolerance a virulence factor that helps bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Survival in extreme environments

15
Q

What is the term for a bacteria that can steal iron from the hemoglobin of RBCs?

A

Siderophore

16
Q

Are curli a virulence factor that helps bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Adherence to host surfaces

17
Q

Is IgA protease a virulence factor that helps bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Adherence to host surfaces and immune evasion

18
Q

What does serum resistance allow bacteria to do?

A

Disrupt the complement cascade, evade the immune system

19
Q

Is antigenic variation a virulence factor that helps bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Immune evasion

20
Q

Are capsules and M proteins virulence factors that help bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Immune evasion

21
Q

LPS, LOS, and teichoic acids are all examples of what?

A

Endotoxins

22
Q

Which bacteria is best known for its actin polymerization “rockets”?

A

Listeria monocytogenes

23
Q

What term describes an inanimate object or substance capable of transferring infectious organisms between hosts?

A

A fomite

24
Q

Are endosome escape pathways virulence factors that help bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Intracellular survival

25
Q

Are type 3&4 secretion systems virulence factors that help bacteria: survival in extreme environments, adherence to host surfaces, immune evasion, intracellular survival, or poison the host?

A

Poison the host/host cell takeover - T3SS and T4SS can inject genes and exotoxins into a host cell.

26
Q

How does Legionella survive after it is taken up by phagocytosis?

A

It prevents the phagosome from fusing with a lysosome, or else inhibits the phagosome from acidifying

27
Q

Coagulase is a Staph. aureus virulence factor that does what?

A

Break down fibrinogen to form a fibrin clot around S. aureus

28
Q

Superantigens belong to what class of bacterial molecules that can also interfere with signal transduction and depolymerize actin?

A

Exotoxins

29
Q

Endotoxins cause an inflammatory immune response that is dominated by what 2 cytokines?

A

TNF and IL-1

30
Q

Are vaccines more useful against endotoxins or exotoxins?

A

Exotoxins - vaccines cannot help against endotoxins

31
Q

In a typical infectious disease timeline, what is the name for the stage dominated by nonspecific immunogenic symptoms like fever and fatigue?

A

Prodrome period

32
Q

In a typical infectious disease timeline, what is the name for the stage where pathogen-mediated symptoms emerge most strongly?

A

Specific-illness period

33
Q

Name the 4 steps of a typical infectious disease timeline.

A

Incubation - Prodrome - Specific-illness - Convalescence/recovery