Clinical Samples

Question 1

Most likely organism?

Gram pos. / Catalase neg. / pharyngitis

Answer 1

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 2

Most likely organism?

Gram pos. / Catalase neg. / UTI

Answer 2

Enterococci

Question 3

Most likely organism?

Gram pos. / Catalase neg. / salt-resistant

Answer 3

Enterococci

Question 4

Most likely organism?

Gram pos. / Catalase neg. / salt-sensitive

Answer 4

S. Bovis

Question 5

Most likely organism?

Gram pos. / Catalase neg. / CAMP + / Hippurate +

Answer 5

S. agalactaie

Question 6

Most likely organism?

Gram pos. / Catalase neg. / endocarditis

Answer 6

Viridans is the most common, but others include…

1) S. Mutans
2) S. bovis
3) Enterococci
4) S. pyogens (from Rheumatic Fever)

Question 7

Most likely organism?

Gram pos. / Catalase neg. / neo-natal sepsis

Answer 7

S. agalactaie (a.k.a. Group B strep)

Question 8

Most likely organism?

Gram pos. / Catalase neg. / acute glomerulonephritis

Answer 8

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 9

Most likely organism?

Gram pos. / Catalase neg. / circumoral palor

Answer 9

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 10

What are the 4 major signs of Scarlet Fever?

What organism causes this?

Answer 10

1) circumoral palor (red cheeks but white ring around lips)
2) Pastia’s lines (red lines around creases of skin)
3) blanching sandpaper rash
4) Strawberry tongue

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 11

What are the signs of the Jones Criteria?

Answer 11

Jones Criteria: 2 Major + 1 minor OR 1

Major

1) Polyarthritis: migrating upwards.
2) Carditis: especially if new heart murmur.
3) Subcutaneous nodules: Painless, firm collections of collagen fibers over bones or tendons.
4) Erythema marginatum: spread outward and clear in the middle to form rings,
5) Sydenham’s chorea (St. Vitus’ dance): rapid movements without purpose of the face and arms. late sequalle

Minor:

1) Fever
2) Arthralgia: Joint pain without swelling
3) Raised sedimentation rate OR C reactive protein
4) Leukocytosis
5) ECG heart block, such as a prolonged PR interval
6) Previous episode of rheumatic fever or inactive heart disease

(Minor symptoms cannot be included if similar major symptoms are included = i.e no duplicates)

Question 12

Most likely organism?

Gram pos. / Catalase neg. / circumoral palor

Answer 12

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 13

What are the signs of the Jones Criteria?

What is it used for?

Answer 13

Jones Criteria: 2 Major + 1 minor OR 1 Major and 2 Minor
Used to DIAGNOSE RHEUMATIC FEVER.

Major

1) Polyarthritis: migrating upwards.
2) Carditis: especially if new heart murmur.
3) Subcutaneous nodules: Painless, firm collections of collagen fibers over bones or tendons.
4) Erythema marginatum: spread outward and clear in the middle to form rings,
5) Sydenham’s chorea (St. Vitus’ dance): rapid movements without purpose of the face and arms. late sequalle

Minor:

1) Fever
2) Arthralgia: Joint pain without swelling
3) Raised sedimentation rate OR C reactive protein
4) Leukocytosis
5) ECG heart block, such as a prolonged PR interval
6) Previous episode of rheumatic fever or inactive heart disease

(Minor symptoms cannot be included if similar major symptoms are included = i.e no duplicates)

Question 14

What organism causes Rheumatic fever?

Answer 14

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 15

What organism causes Rheumatic fever?

Answer 15

Streptococcus pyogenes (a.k.a. Group A Strep)

Question 16

List some key features of…

Streptococcus Pneumoniae

Answer 16

Gram POSITIVE 
catalase NEGATIVE
oxidase NEGATIVE 
bile SOLUBLE (sensitive) 
optochin SENSTITIVE 
ALPHA HEMOLYTIC 
(CSF uses latex aggulination test to confirm meningitis) 

Treatment: 
penecillin G (severe)
Penicillin V (moderate to mild infection)  

Prevention:
polysaccharide vaccine available