III - Infection Biology Flashcards Preview

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Flashcards in III - Infection Biology Deck (58)
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1
Q

Microbes that can cause disease

A

pathogens

2
Q

Pathogens that cause disease only in the immunocompromised

A

opportunistic pathogens

3
Q

Measure of a microbe’s ability to cause disease

A

virulence

4
Q

Virulence is determined by

A

virulence factors - capsule, endotoxin, exotoxin

5
Q

Number of organisms required to cause disease in 50% of the population

A

ID50

6
Q

Presence of microbes, symptoms of disease

A

infection

7
Q

Mechanisms of Bacterial Disease

A

production of toxins, induction of inflammation

8
Q

Human-Human Bacterial Transmission

A

sexual, fecal-oral, inhalation, transplacental, blood

9
Q

Non-Human-Human Bacterial Transmission

A

soil, water, animal, vector, feces, fomites

10
Q

Mediates attachment of bacteria

A

pili

11
Q

Mediates strong adherence to the surface of human cells

A

glycocalyx

12
Q

Surface protein of Salmonella and E. coli that mediate binding to endothelium and to extracellular proteins such as fibronectin

A

curli

13
Q

Bacterial Invasion: Spread through subcutaneous tissue

A

collagenase, hyaluronidase

14
Q

Bacterial Invasion: Accelerates formation of a fibrin clot coating the organisms with a layer of fibrin

A

coagulase

15
Q

Bacterial Invasion: Allows adherence to mucous membranes

A

IgA protease

16
Q

Bacterial Invasion: Destroys both neutrophilic leukocytes and macrophages

A

leukocidin

17
Q

Bacteria with IgA Protease

A

Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Neisseria gonorrhoeae

18
Q

Protects against phagocytosis

A

polysaccharide capsule

19
Q

Anticapsular antibodies allow more effective phagocytosis to occur

A

Opsonization

20
Q

Antiphagocytic cell wall protein of S. pyogenes

A

M Protein

21
Q

Cell wall protein of S. aureus that prevents complement activation

A

Protein A

22
Q

Exotoxin: Source

A

gram (+), gram (-)

23
Q

Exotoxin: Secreted from cell?

A

yes

24
Q

Exotoxin: Chemical Compound

A

polypeptide

25
Q

Exotoxin: Location of Genes

A

plasmid, bacteriophage

26
Q

Exotoxin: Toxicity

A

high

27
Q

Exotoxin: Antigenicity

A

high

28
Q

Exotoxin: Vaccine

A

toxoids

29
Q

Exotoxin: Heat Stability

A

destroyed at 60°C (except Staphylococcal enterotoxin)

30
Q

Exotoxin: Typical Diseases

A

tetanus, botulism

31
Q

Endotoxin: Source

A

gram (-)

32
Q

Endotoxin: Secreted from cell?

A

no

33
Q

Endotoxin: Chemical Compound

A

lipopolysaccharide

34
Q

Endotoxin: Location of Genes

A

bacterial chromosome

35
Q

Endotoxin: Toxicity

A

low

36
Q

Endotoxin: Antigenicity

A

low

37
Q

Endotoxin: Heat Stability

A

stable at 100°C for 1 hour

38
Q

Endotoxin: Typical Diseases

A

meningococcemia

39
Q

Polypeptides secreted by certain bacteria that alter specific cell functions resulting in the symptoms of disease

A

exotoxins

40
Q

Exotoxins: Active subunit, toxic, less toxic in toxoids

A

A subunit

41
Q

Exotoxins: Binding subunut

A

B subunit

42
Q

All exotoxins are heat-labile except

A

Staphylococcal enterotoxin

43
Q

MoA of Exotoxins: Diphtheria, cholera, E.coli heat-labile toxin, pertussis

A

ADP-ribosylation

44
Q

MoA of Exotoxins: Toxic Shock Syndrome, Staphylococcal enterotoxin, erythrogenic toxin

A

Superantigen

45
Q

MoA of Exotoxins: Tetanus, botulinum, lethal factor of anthrax toxin, Scalded Skin toxin

A

Protease

46
Q

MoA of Exotoxins: Clostridium perfringens alpha toxin

A

Lecithinase

47
Q

Can elicit widespread activation of the complement and coagulation cascades

A

Superantigens

48
Q

Lipoplysaccharides located in the outer membrane of gram (-) bacteria

A

endotoxins

49
Q

Toxic component of LPS

A

Lipid A

50
Q

Induces the overproduction of cytokines such as TNF and IL-1, activates the complement and coagulation cascade resulting in disseminated intravascular coagulation

A

Lipid A

51
Q

All bacteria have cell walls composed of peptidoglycan except

A

Mycoplasma pneumoniae

52
Q

Only gram (+) bacteria with endotoxin

A

Listeria monocytogenes

53
Q

All bacterial capsules are composed of polysaccharide except

A

Bacillus anthracis

54
Q

All exotoxins are heat-labile except

A

Staphylococcal enterotoxin

55
Q

Determine whether antibodies are present in a patient’s serum, detect the antigens of the organism in tissues or body fluids, at least a fourfold increase in titer between the acute and convalescent samples, IgM antibody for acute infection

A

Serologic Tests

56
Q

Nucleic acid amplification tests, nucleic acid probes, nucleic acid sequence analysis

A

Molecular Tests

57
Q

Highly specific, sensitive, faster than culture

A

Molecular Tests

58
Q

Useful for bacteria that are difficult to culture such as Chlamydia and Mycobacterium

A

Molecular Tests