Lecture 10 Flashcards

1
Q

Regarding case 10, what was the initial clinical finding that 3 of 4 kids and their mother developed? What is the pathogen that usually causes this symptom?

A

Sore Throat Group A strep

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2
Q

Regarding case 10, what was the skin finding that 2 children developed? What were the 3 potential causes for this finding?

A

Sun burn like rash Strep scarlet fever Strep TSS Staph TSS

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3
Q

Regarding case 10, when assumed that the pharyngitis was caused by strep, the drug chosen to treat was _. Why?

A

Penicillin G Majority of Group A strep strains are penicillin sensitive

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4
Q

Regarding case 10, the infecting organism was _ hemolytic. What were 2 other characteristics of the cultured colonies?

A

Beta hemolytic Highly mucoid and bacitracin sensitive

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5
Q

Regarding case 10, what strain was found to cause the family’s illness? What is its virulence factor?

A

M18 Group A strep Superantigen SPE-C

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6
Q

What type of inflammatory disease is associated with M18 Group A strep? This organism produces superantigen SPE-C. What is another name for the super antigen?

A

Rheumatic fever Scarlet fever toxin type C

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7
Q

What is the criteria for rheumatic fever?

A

Repeated group Astreptococcal infection with the last one approximately 10 days ago, carditis, arthritis, and shaking palsy known as Sydenham’s chorea

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8
Q

What is the neurological disease associated with group A strep?

A

PANDAS

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9
Q

What are the 2 drugs that are used to treat M18 group A strep?

A

Augmentin Clindamycin

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10
Q

Why must all group A strep be treated with antibiotics?

A

Prevents progression to rheumatic fever

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11
Q

What are the 4 medically significant beta hemolytic streptococci? Which causes 90% of all infections?

A
  • Group A (β-hemolytic) S. pyogenes (90%)
  • Group B (β-hemolytic) S. agalactiae
  • Group C (β-hemolytic) S. equisimilis
  • Group G (β-hemolytic) S. dysgalactiae
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12
Q

What are the 2 members of group D strep? What type of hemolysis do they display?

A

Enterococcus, S. bovine

-hemolytic

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13
Q

What is the major criteria by which streptococci are categorized?

A

Acid extractable C carbohydrates allow placements in various groups

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14
Q

What usually alpha hemolytic streptococcus is usually part of the normal flora of the throat?

A

Viridans

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15
Q

Group A strep are typed based on their M proteins. How many of these M proteins exist? How do they assist virulence?

A

Over 150 M proteins Form antiphagocytic surface proteins (MSCRAMM)

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16
Q

In the presence of oxygen, what mediates beta hemolysis for group A strep? What about in the absence of oxygen?

A

In O2 - Streptolysin S

W/out O2 - Streptolysin O and S

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17
Q

What is the most common infection caused by group A strep? What are 2 ways it is transmitted?

A

PharyngitisDroplet and Direct contact

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18
Q

What is the major skin infection transmitted by Group A strep? How is it transmitted?

A

Impetigo Direct Contact

19
Q

Undet what conditions is group A strep able to cause invasive disease?

A

It needs to get through breaks in skin

20
Q

What are the 5 cell surface virulence factors associated with Group A strep?

A
M protein
C5a peptidase 
Hyaluronic acid capsule 
Fibronectin binding proteins 
IgG and IgA Fc binding proteins
21
Q

What cell surface virulence factors of group A strep is associated rheumatic fever? How?

A

M proteinAntibodies to M protein cross react with hear myosin and tropomyosin

22
Q

What is the cell surface virulence factor of group A strep that repels PMNs and macrophages?

A

Hyaluronic acid capsule

23
Q

What virulence factors of Group A strep are associated with necrotizing tissue damage?

A

Streptolyin S Streptokinase Cysteine Protease

24
Q

What Group A strep virulence factor is diagnostic by antibody testing?

A

Streptolysin O

25
Q

What are the serotypes of streptococcal superantigen? How do they cause illness?

A

SPE A, C, G-L, SMEZ, and SSA

Cause massive cytokine production and TSS

26
Q

Inflammatory throat infection with fever, involving the tonsils. This is a description of _. This is associated with high or low M types of group A strep?

A

Pharyngitis Low M types

27
Q

Inflammatory skin infection, usually with fawn-coloredpatches around mouth and nose. This is a description of _. This is associated with high or low M types of group A strep?

A

Impetigo High M types

28
Q

Subcutaneous, highly inflammatory infection; usuallyhighly marginated and having high fever. This is a description of _.

A

Erysipelas

29
Q

When group A strep causes invasive infections, what are the 2 descriptions of likely disease provided in the notes?

A

– Sepsis without hypotension ± necrotizing fasciitis and myositis
– TSS with hypotension ± necrotizing fasciitis and myositis

30
Q

What is the cause of rash associated with scarlet fever? What region of the US is more associated with scarlet fever like rash?

A
  • Delayed hypersensitivity to strep antigens and the superantigens
  • More common in Northern US
31
Q

Strawberry tongue is a finding associated with _

A

Scarlet fever

32
Q

Under what conditions can superantigen cause a blunted immune response?

A

When it is produced in overwhelming quantities

33
Q

What are the 5 diseases discussed as part of the delayed sequelae associated with Group A strep?

A

Rheumatic fever Acute Glomerulonephritis Guttate Psoriasis Erythema nosodum PANDAS

34
Q

Development of rose-petal shaped lesions in geneticallysusceptible persons following group A strep infection describes _

A

Guttate psoriasis

35
Q

A disease of valves and veins, with painful nodular lesions, usually on arms and legs due to immune complex disease following group A strep infection describes _

A

Erythema nodosum

36
Q

Neuropsychiatric disorder that develops followng group A strep infection refers to _

A

PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococci)

37
Q

Carditis, fever, arthritis, Sydenhams chorea are all associated with _. This is cause by high or low type group A strep? How is it diagnosed?

A
  • Rheumatic fever

- Low type, especially M18-ASO (antistreptolysin O) antibody titer

38
Q

How long before the manifestation of group A strep delayed sequelae diseases?

A

Occur 10-15 days following last infection

39
Q

A immune system kidney disease associated with hypertenstion, proteinuria or hematuria that develops after group A strep Infection is likely _. Is this disease associated with high or low levels of complement in the blood? What 2 antibodoes are diagnostic?

A

Acute glomerulonephritis Low circulating complement levels Antibodies against DNase B or ASO

40
Q

What type of disease is associated with a aschof bodies? Where are they found?

A

Rheumatic fever Found in heart tissue

41
Q

Beyond penicillin, what is another drug that can be used to treat acute pharyngitis, impetigo and erysipelas?

A

Azithromycin

42
Q

What are the 5 steps needed for the treatment of sever invasive diseases caused by group A strep?

A
  • Multiple antibiotics (clindamycin to shut off exotoxins)
  • Supportive care for hypotension
  • Tissue debridement for necrotizing diseases
  • IVIG for TSS
  • Activated protein C for purpura fulminans.
43
Q

For children who develop rheumatic fever, how long are they treated with antibiotics? What other type of drug can be used for their treatment?

A

Antibiotics till 21

Also use anti-inflammatories

44
Q

What are the 4 secreted exotoxins associated with group A strep?

A

Hemolysin
Streptokinase
Streptococcal pyrogenic exotoxin
Cysteine protease