Cardiac Microbiology (FREITAS) Flashcards

1
Q

Discuss Bacteremia:

  • Define bacteremia:
  • What can cause bacteremia? (6)
  • What symptoms are present in bacteremia?
A

Bacteremia:

  • Presence of bacteria in the bloodstream
  • Possible Causes:
    • Vigorous tooth brushing
    • Dental or medical procedures
    • Periodontal disease
    • Infections such as pneumonia or UTI
    • Artificial joint or heart valve
    • Heart valve abnormalities
  • Bacteremia is asymptomatic
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2
Q

Discuss Septicemia:

  • Define septicemia:
  • What is “sepsis of the blood”?
  • What are the 3 symptoms associated with Septicemia?
A

Septicemia

  • Bacteremia (bacterial invasion) + Toxin production = septicemia
  • “Sepsis of the blood” is blood poisoning by bacteria
  • Symptoms: Fever, rapid heart rate and difficulty breathing
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3
Q

Discuss Septic Shock:

  • Results as a complication of severe infection and ______.
  • What can it cause?
  • Who are the most at risk?
A

Septic Shock

  • Results as complication of severe infection and sepsis
  • It can cause multiple organ failure
  • Affects: children, elderly and immunocompromised
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4
Q

Inflammatory reaction mediated by cytokines and chemokines. Eg. viral, bacterial infection, pacemaker infection.

A. Direct invasion

B. Indirect damage

C. Effect of circulating toxins

D. All of the above

A

A. Direct invasion

Direct invasion = viral, bacterial infection, pacemaker infection

Indirect damage = Rheumatic carditis

Effect of circulating toxins = Diphtheria

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5
Q

Cell damage (eg. Diphtheria) describes which of the following?

A. Direct invasion

B. Indirect damage

C. Effect of circulating toxins

D. All of the above

A

C. Effect of circulating toxins

Direct invasion = viral, bacterial infection, pacemaker infection

Indirect damage = Rheumatic carditis

Effect of circulating toxins = Diphtheria

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6
Q

Autoimmune mechanisms through molecular mimicry. (eg. Rheumatic carditis)

A. Direct invasion

B. Indirect damage

C. Effect of circulating toxins

D. All of the above

A

B. Indirect damage

Direct invasion = viral, bacterial infection, pacemaker infection

Indirect damage = Rheumatic carditis

Effect of circulating toxins = Diphtheria

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7
Q

Discuss Myocarditis:

  • Define Myocarditis:
  • What is the most common etiology of Myocarditis?
A

Myocarditis

  • Myocarditis: Acute or chronic inflammation of the myocardium
    • Inflammatory cells infiltrate
    • Myocytes necrosis or degeneration
    • Viral is the most common cause of Myocarditis
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8
Q

All of the following are DNA viruses that cause Myocarditis EXCEPT:

A. Adenoviruses

B. Cytomegalovirus

C. Epstein-Barr virus

D. Herpes virus

E. Influenza viruses

A

E. Influenza viruses

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9
Q

What are the 4 DNA viruses of Myocarditis?

A

Adenoviruses, Cytomegalovirus, Epstein-Barr virus and Herpes virus

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10
Q

What are the 3 phases of viral myocarditis?

A
  1. Phase 1 (Viremia): initial myocardial injury; innate immune response
  2. Phase 2 (Viral Cleaning): activation of adaptive immunity
  3. Phase 3: Acute myocarditis could lead to chronic dilated cardiommyopathy, fibrosis, cardiac dilation and heart failure
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11
Q

What are the 4 bacteria associated with bacterial myocarditis?

A
  1. S. aureus
  2. Streptococcus
  3. Mycobacterium Tuberculosis
  4. C. diphtheria
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12
Q

What are the 3 predisposing factors for bacterial myocarditis?

A
  • Immunosuppress state
  • Infected prosthesis
  • Correlated with endocarditis
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13
Q

Discuss Rheumatic Myocarditis:

  • Define Rheumatic myocarditis:
    • What bacteria is associated?
  • What is the characteristic lesion of Rheumatic Myocarditis?
A

Rheumatic Myocarditis

  • Rheumatic fever is a nonsuppurative complication of S. Pyogenes pharyngitis
  • Is a chronic condition resulting from rheumatic fever
  • Aschoffs nodules
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14
Q

What are the 2 parasites associated with myocarditis?

A

T. cruzi and Tichinella spiralis

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15
Q

Discuss Pericarditis:

  • Define it:
  • Discuss the fluid in between the layers of the pericardium and how it contributes to pericarditis:
  • What are the 4 types of pericarditis?
  • Pericarditis usually co-exists with ______.
  • What is the most common infection cause?
  • What are the 5 symptoms associated with pericarditis?
A

Pericarditis:

  • When the pericardium becomes inflamed, the amount of fluid between the two layers of pericardium increases - pericardial effusion
  • Types of Pericarditis
    • Fibrinous
    • Serous
    • Caseous
    • Purulent or suppurative pericarditis
  • Pericarditis usually co-exists with endocarditis
  • Viral infections are the most common cause
  • Symptoms
    • Chest pain
    • palpation
    • pain when swallowing or breathing
    • fever
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16
Q

Exudative inflammation caused by trauma:

A. Fibrinous pericarditis

B. Serous pericarditis

C. Caseous pericarditis

D. Purulent or Suppurative pericarditis

A

A. Fibrinous pericarditis

Fibrinous = Exudative inflammation caused by trauma

Serous = Viral infection or due to autoimmune disease

Caseous = TB in origin

Purulent or Suppurative = invasion of pericardial space by microbes

17
Q

Tuberculous in origin:

A. Fibrinous pericarditis

B. Serous pericarditis

C. Caseous pericarditis

D. Purulent or Suppurative pericarditis

A

C. Caseous pericarditis

Fibrinous = Exudative inflammation caused by trauma

Serous = Viral infection or due to autoimmune disease

Caseous = TB in origin

Purulent or Suppurative = invasion of pericardial space by microbes

18
Q

Viral infection or due to autoimmune diseases (rheumatoid arthritis, SLE):

A. Fibrinous pericarditis

B. Serous pericarditis

C. Caseous pericarditis

D. Purulent or Suppurative pericarditis

A

B. Serous pericarditis

Fibrinous = Exudative inflammation caused by trauma

Serous = Viral infection or due to autoimmune disease

Caseous = TB in origin

Purulent or Suppurative = invasion of pericardial space by microbes

19
Q

Invasion of the pericardial space by microbes:

A. Fibrinous pericarditis

B. Serous pericarditis

C. Caseous pericarditis

D. Purulent or Suppurative pericarditis

A

D. Purulent or Suppurative pericarditis

Fibrinous = Exudative inflammation caused by trauma

Serous = Viral infection or due to autoimmune disease

Caseous = TB in origin

Purulent or Suppurative = invasion of pericardial space by microbes

20
Q

_______ is the most common form of pericardial infections.

A

Viral pericarditis

21
Q

All of the following bacteria are associated with bacterial pericarditis EXCEPT:

A. Staphylococcus

B. Streptococcus

C. Pneumococcus

D. C. Diphtheria

E. M. Tuberculosis

A

D. C. Diphtheria

Diphtheria = Myocarditis (bacterial)

22
Q

What are the most common viruses associated with viral pericarditis?

A
  • Echo and Coxsackie viruses A/B
  • Cytomegalovirus in immunocompromised
23
Q

All of the following parasites are associated with parasitic pericarditis EXCEPT:

A. Toxoplasmosis

B. Toxoplasma gondii

C. Echinococcosis

D. Trypanosoma cruzi

A

D. Trypanosoma cruzi

Myocarditis = T. cruzi and T. spiralis

24
Q

Discuss Endocarditis:

  • Define Endocarditis
  • What are the two predisposing factors?
  • What are the 2 types of Endocarditis?
  • What are the 4 main bacteria involved in endocarditis?
A

Endocarditis:

  • infection of the endocardium (inner lining of the heart chambers and heart valves)
  • Predisposing conditions: endocardial abnormality and bacteremia
  • Two types of Endocarditis:
    • Acute: appears suddenly and can be fatal
    • Sub-acute: develops slowly aand may cause death within a year
  • Bacteria involved in endocarditis:
    • S. aureus
    • S. pyogenes
    • S. epidermidis
    • Viridian group
25
Q

Which of the following are associated with Vegetations?

A. Myocarditis

B. Pericarditis

C. Endocarditis

D. all of the above

A

C. Endocarditis

  • In infective endocarditis, vegetations refer to bacteria in blood stream that adhere to the thrombi (platelets and fibrin form due to endothelial damage)
  • Vegetations constitutes the primary pathology of infectious endocarditis
26
Q

________ constitutes the primary pathology of infective endocarditis.

A

Vegetations

27
Q

Discuss the 6 steps in the pathogenesis of infectious Endocarditis:

A

1. Endothelial damage

  • breach of the endocardium

2. Thrombosis formation

  • platelet aggregates on the breached endocardium, detach and embolize

3. Microorganism adhere

  • organisms circulating in blood attach to thrombotic endocardium

4. Vegetation formation

  • platelet-fibrin-bacterial mas
    5. once the organisms are attached to the lesion, they multiply and colonize this site
28
Q

In Rheumatic Endocarditis small vegetations called _______ are visible along the mitral valve leaflet.

A

Verrucae

29
Q

What are the 5 specific signs of Rheumatic Endocarditis?

***may be exam Q***

A
  1. Roth spots
  2. Petechiae
  3. Splinter hemorrhages
  4. Janeway lesions
  5. Olser node
30
Q

All of the following are signs of Rheumatic Endocarditis EXCEPT:

A. Roth spots

B. Petechiae

C. Janeway lesions

D. Aschoffs nodules

E. Osler node

A

D. Aschoffs nodules

Rheumatic Myocarditis = Aschoffs nodules

Rheumatic Endocarditis = Osler node