Review Lesson 9: Streptococcus pyogenes Flashcards

1
Q
1.	Know the following characteristics about each disease studied:
Genus and species name
Gram reaction
Cell shape
Disease name
Transmission
Virulence factors
Clinical symptoms of disease
Treatment
A
Genus name: Streptococcus
species name: pyogenes
Gram reaction: +
Cell shape: coccus
Disease name:
Transmission:
Virulence factors:
Clinical symptoms of disease:
Treatment:
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2
Q
  1. Be able to translate the organism’s genus and species name into the English language as given in class.
A

Chain former, pus generating

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3
Q
  1. What are the three hemolytic reactions for classifying Strep bacteria?
A

Strep Classification by Hemolytic Reaction
Alpha(α) – hemolysis: partial destruction of RBC; greenish color on blood agar
Beta(β) – hemolysis: complete destruction of RBC; clear zone around bacteria
Gamma(γ) – hemolysis: no reaction with RBC

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4
Q
  1. What is the hemolytic reaction for: S.aureus and S.pyogenes?
A

Beta hemolytic

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5
Q
  1. On what characteristic of the bacteria cell is Rebecca Lansfield’s system of classifying Strep bacteria based?
A

Rebecca Lansefield Classification of Strep
Based on distinct cell wall Ags
Each Ag is designated with a letter (A – O)
(Lansefield devoted much of her life research to studying Strep bacteria)

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6
Q
  1. The M protein protects S.pyogenes from what host resistant mechanism?
A

M protein:
located in cell wall
interferes with phagocytosis

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7
Q
  1. What is Hyaluronidase?
A

Hyaluronidase: destroys hyaluronic acid; leads to tissue penetration

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8
Q
  1. What is Otitis Media?
A

Middle ear infection

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9
Q
  1. What is the source of the erythrogenic toxin of Scarlet fever?
A

Source: Prophage(virus) genome integrated into bacterial chromosome

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10
Q
  1. What category of virulence factors does erythrogenic toxin belong?
A

Exotoxins

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11
Q
  1. After recovery of Scarlet fever, does permanent immunity occur (listen to the audio lecture)?
A

Complete immunity for life

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12
Q
  1. What is a prophage?
A

Virus

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13
Q
  1. Why is a prophage involved in the symptoms of Scarlet fever?
A

Refer to handout

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14
Q
  1. If the prophage is removed from S. pyogenes, does the bacteria still cuase disease? If so, what disease?
A

Yes, strep throat

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15
Q
  1. What are the two late sequelae of Streptococcal pharyngitis?
A

Rheumatic Heart Disease, Acute Glomerulonephritis

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16
Q
  1. Is Scarlet fever a late sequelae? Why or why not?
A

No it’s not. It happens at the same time.

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17
Q
  1. Why has there been a dramatic decline in Rheumatic Heart Disease cases in the USA?
A

Early detection, antibiotics available,

18
Q
  1. Why is Rheumatic Heart Disease described as an Autoimmune disorder?
A

Antibodies will attack heart valves along with S. pyrogens

19
Q
  1. Is Rheumatic Heart disease caused by a bacteria infection to the heart?
A

Complications of a Strep throat infection

20
Q
  1. What valve of the heart is damaged the most in rheumatic heart disease by antibody attack?
A

Mitral valve

21
Q
  1. What percentage of patients have Carditis from Rheumatic Heart Disease?
A

50%

22
Q
  1. Between what 2 chambers of the heart is the Mitral valve located?
A

Left atrium and left ventricle

23
Q
  1. Can antibiotics be used to treat the symptoms of Rheumatic Heart disease? Why or why not?
A

Yes

24
Q
  1. Is Rheumatic Heart disease contagious?
A

No it’s not contagious

25
Q
  1. Why do patients recovering from Rheumatic Heart disease need to be on long term antibiotics if the disease is not caused by a bacteria infection?
A

They are more susceptible to getting and if they get it, it can mutate and be harder to treat.

26
Q
  1. Is Acute glomerulonephritis a common or rare disease?
A

Rare

27
Q
  1. What causes damage or even complete destruction to the glomerulus of the nephron kidney unit?
A

Complete stoppage like drain, due to immune complex disease

28
Q
  1. What is edema?
A

Swelling

29
Q
  1. Would you expect the blood pressure to initially increase or decrease because of a failure of the kidney nephron system in acute glomerulonephritis?
A

Increase due to all the pressure

30
Q
  1. Is Acute glomerulonephritis contagious? Why or why not?
A

No

31
Q
  1. Is Acute glomerulonephritis more common in males or females?
A

Male

32
Q
  1. What is hematuria?
A

Blood in urine

33
Q
  1. What is the best prevention to decrease chances of a late sequelae developing from a Strep throat infection?
A

Early detection, complete antibiotic treatment

34
Q
  1. Define necrotizing.
A

Dead tissue
No blood supply
Anaerobic

35
Q
  1. Define fasciitis.
A

White/ gray, connective tissue, thick or thin

Inflammation of

36
Q
  1. What are the 2 virulence factors involved in the aggressive tissue damage associated with necrotizing fasciitis?
A

Pyrogenic exotoxin A

Exotoxin B

37
Q
  1. What is a super antigen?
A

Bacteria exotoxin
Not processed intracellular by MØ for presentation to T-cells
Bind directly to T-cells without specificity
Effects 2 – 20% of T-cell population
Many T-cells die from excessive stimulation

38
Q
  1. Why are antibiotics not very effective in treating necrotizing fasciitis?
A

Drug therapy: Penicillin (early) but no effect on toxins or on bacteria in necrotic tissue

39
Q
  1. Is there a blood supply to necrotic tissue?
A

No

40
Q
  1. If a surgeon debrides away necrotic tissue, what is he/she doing?
A

Remove dead tissue until they get to healthy pink. That way antibiotic can help treat

41
Q
  1. What would be the reason behind removal of necrotic tissue to effect a cure?
A

Relieve pressure of swollen tissue

Amputation may be necessary

42
Q
  1. Which S.pyogenes infection did we study that doesn’t involve strep throat as a primary infection?
A

Necrotizing Fasciitis