Pneumonia, Rheumatic Fever, Endocarditis

Question 1

Gram positive cocci are observed under a microscope. They are catalase negative. What type of cocci are they?

Answer 1

Streptococci

Question 2

A streptococcus was identified and hemolytic classification was performed. The blood agar is shown below. The bug is alpha hemolytic and bile sensitive. What is the bug?

Answer 2

Streptococcus pneumoniae

Question 3

What are the virulence factors of S. pneumoniae?

Answer 3

Capsule and Leukocidin

Question 4

Is there a vaccine available for pneumococcus? Who is it generally administered to? What does it contain?

Answer 4

Yes; Children and elderly; Polysaccharide capsule in polyvalent vaccine.

Question 5

What is the traditional Tx for pneumonia? Alternate? What is an important test to perform in determining Tx?

Answer 5

Penicillin/Erythromycin; Vancomycin; AB sensitivity/resistance testing

Question 6

What are other important pathogens that cause pneumonia?

Answer 6

• Group B streptococci (S. agalactiae)
• Klebsiella
• S. aureus
• HACEK group of gram negative rods (Haemophilus, Actinobacillus actiomcetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella species)

Question 7

What strains of bug cause Rheumatic Fever?

Answer 7

• Group A streptococci (S. pyogenes) - M3, M5, M13 strains

Question 8

What are the clinical features of Rheumatic Fever?

Answer 8

• Fever
• Polyarthris
• Endocarditis
• Myocarditis (Murmur)

Question 9

A patient presents with rheumatic fever. A heart biopsy is performed and the following morphology is found. What is this?

Answer 9

Aschoff body

Question 10

How is rheumatic fever Dx?

Answer 10

• IgM anti-Streptolysin O Ab
• Lesions/joints are sterile

Question 11

What are serious complications of Rheumatic fever? What can these complications predispose a patient to?

Answer 11

Fibrosis/calcification of endocardium, permanent valve distortion; Life-long risk of endocarditis

Question 12

What is the Tx for rheumatic fever?

Answer 12

Aspirin/steroids to treat Syx

Question 13

What are preventative measures for those who have Hx of RF?

Answer 13

Aggressive AB Tx (Penicillin/Erythromycin)

Question 14

Blood is taken from a patient with endocarditis and cultured. The bug is alpha hemolytic and bile resistant. What is the bug? Where

Answer 14

Streptococcus viridans

Question 15

What bug is expected to cause endocarditis in patients with IV lines or drug abusers?

Answer 15

S. aureus

Question 16

What are the typical lesions found in endocarditis? What is a major problem with treatment of endocarditis?

Answer 16

Vegetations; ABs don’t penetrate vegetation well

Question 17

A patient with endocarditis shows the following lesions. What are they?

Answer 17

Splinter hemorrhages caused by fragments of septic vegetations

Question 18

What are the preventative measures undergone by patients at risk for endocarditis?

Answer 18

Prophylactic ABs at the time of dental Tx, Catheterization

Question 19

What type of organisms are catalase positive? How effective is the Pneumovax vaccine against these organisms?

Answer 19

Staphylococcus; Not at all. Pneumovax only protects patients from pneumococcus (catalase negative)

Question 20

Why is bacterial pneumonia more common in the winter?

Answer 20

Viral coughs and colds predispose patients to pneumonia and are more common in the winter

Question 21

What is the value of penicillin in the management of Rheumatic Fever?

Answer 21

Can prevent a recurrent attack in a patient with a history of the condition.

Question 22

In which of the following conditions is the bug likely to be found in the blood?

• Streptococcal phryngitis
• Pneumococcal pneumonia
• Bacterial Endocarditis
• Rheumatic Fever

Answer 22

Penumococcal pneumonia and Bacterial endocarditis

Question 23

Which of the following conditions is the anti-streptolysin Ab assist the Dx?

• Streptococcal pharyngitis
• Pneumococcal pneumonia
• Bacterial endocarditis
• Rheumatic fever

Answer 23

Rheumatic fever