19- Streptococcus

Is Streptococcus gram-positive or gram-negative?

Gram-positive

Is Streptococcus facultative anaerobes or aerobes?

Anaerobes

Is Streptococcus catalase positive or negative?

Negative

What are the major classes of Streptococci?

- Streptococcus
- Enterococcus
- Peptoniphilus

Are Streptococcus usually motile?

No

Are Streptococcus usually hemolytic?

Yes

Where are most Streptococcus species commensal of?

- Upper respiratory tract
- Lower urogenital tract

True or false:
Streptococcus are capsulated

True

Classify the following strains as either alpha-hemolytic or beta-hemolytic:
A. S. pneumoniae
B. S. equi
C. S. pyogenes
D. S. suis
E. S. agalactiae
F. S. zooepidimicus
G. S. dysgalactiae
H. S. uberis
I. S. porcinus
J. S. canis

Alpha-hemolytic: B, C, E, F, I, J
Beta-hemolytic: A, D, G, H

Describe the 3 categories of hemolysis

- Alpha-hemolysis: partial destruction of RBCs, produces greenish color
- Beta-hemolysis: complete destruction of RBCs, clearing around growth
- Gamma-hemolysis: no destruction, no change in the media

What are methods to differentiate Streptococcus species?

- Lancefield grouping
- PCR
- Molecular typing

What are the most important specific infections from Streptococcus?

- Strangles in horses
- Pneumonia/meningitis in porcine
- Mastitis in bovine

What kind of Lancefield group and hemolytic group is Streptococcus agalactiae?

- Group B
- Beta-hemolytic

What kind of Lancefield group and hemolytic group is Streptococcus dysgalactiae?

- Group C
- Alpha-hemolytic

What kind of Lancefield group and hemolytic group is Streptococcus uberis?

- Unassigned group
- Alpha-hemolytic

What does S. agalactiae cause in cattle?

Bovine mastitis

What does S. dysgalactiae cause in cattle?

Bovine mastitis

What does S. uberis cause in cattle?

Bovine mastitis

What Streptococcus species cause bovine mastitis?

- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

Which of the following Streptocci species that cause bovine mastitis have beta-hemolysis:
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

S. agalactiae

Which of the following Streptocci species that cause bovine mastitis have alpha-hemolysis:
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

Which of the following Streptocci species that cause bovine mastitis are CAMP-positive?
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

S. agalactiae

Which of the following Streptocci species that cause bovine mastitis are CAMP-negative?
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

Which of the following Streptocci species that cause bovine mastitis have aesculin hydrolysis on Edwards medium?
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

- S. uberis
- Enterococcus faecalis

Which of the following Streptocci species that cause bovine mastitis grow on MacConkey agar?
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

Enterococcus faecalis

What are the Lancefield groups of the following Streptocci species that cause bovine mastitis?
- S. agalactiae
- S. dysgalactiae
- S. uberis
- Enterococcus faecalis

- B
- C
- Not assigned
- D

What group of antibiotics is bovine mastitis very susceptible to?

Beta-lactams

What Streptococcus species causes strangles in horses?

S. equi subspecies equi

What are clinical signs of strangles?

- Nasal discharge
- Decreased appetite
- Fever
- Swelling of lymph nodes that may obstruct the airway
- Puss secretion from abscesses

What other Streptococcus species must S. equi equi be distinguished from to diagnose strangles?

- S. equisimilis
- S. zooepidemicus

What are the Streptococcus species that are Lancefield group C?

- S. equisimilis
- S. equi
- S. zooepidemicus

How is S. equi induced strangles differentiated from S. equisimilis and S. zooepidemicus? What should S. equi show that makes it stand out?

- Sugar fermentation
- Negative for fermentation for everything but maltose

What antibiotic can be used for strangles? When should this antibiotic not be given?

- Penicillin
- Don't give if external lymph nodes affected

Is there a vaccine for strangles?

Yes

What Streptococcus species affects pigs?

S. suis

True or false:
S. suis is zoonotic

True

What does S. suis cause in pigs? What is the main disease?

- Meningitis: main
- Arthritis
- Septicemia
- Bronchopneumonia

What can S. suis cause in humans?

- Meningitis
- Septicemia
- Streptococcal toxic shock-like syndrome

What kind of Lancefield group and hemolytic group is Streptococcus suis?

- Group D
- Alpha-hemolytic

Is there a vaccine for S. suis?

Yes

What drugs can be used against S. suis?

- Penicillin
- Ampicillin

What species does Streptococcus pyogenes affect?

Humans

What are the types of S. pyogenes? What does each cause?

- Suppurative: Skin/soft tissue disease
- Non-suppurative: rheumatic fever
- Superantigen medicated: scarlet fever

What species does S. pneumoniae affect? What does it cause?

- Humans
- Pneumonia
- Septic meningitis

What drug can be used against S. pneumoniae?

Penicillin

Is there a vaccine for S. pneumoniae?

Yes