Strep Review for Exam 1

Question 1

Which Lancefield group is S. suis?

Answer 1

Group D

Question 2

Which 2 virulence factors are required for virulence in type 2 disease of S. suis?

Answer 2

1. Muramidase-released protein
2. Extracellular protein factor

Question 3

Suilysin is a cholesterol-binding hemolysin of which organism?

Answer 3

Strep suis

Question 4

Is there a vaccine for Strep suis?

When would a vaccine be most effective?

Answer 4

Yes

Give vaccine to SOW prior to farrowing

Question 5

Which organism has zoonotic potential and causes similar disease in both the animal and human being?

What are those similar disease processes?

Answer 5

Strep suis

Septicemia, meningitis, arthritis, bronchopneumonia

Question 6

Which type of hemolysis does S. agalactiae have?

Answer 6

Narrow zone beta hemolysis

Question 7

S. agalactiae is an obligate pathogen of which environment?

Answer 7

Intramammary

Question 8

1. What makes S. agalactiae so easy to manage?
2. How do you treat?

Answer 8

1. It’s an obligate intramammary pathogen
2. Infuse penicillin into the mammary

Question 9

What Lancefield group is S. dysgalactiae a part of?

Answer 9

Group C

Question 10

How might S. dysgalactiae gain entry and cause disease?

Answer 10

Gains entry into the streak canal via wounds and sores involving the teat orifice

Question 11

What happens in alpha hemolysis that gives it the “green” appearance?

Answer 11

RBCs are still present, but the hemoglobin has been converted to methemoglobin, which has a green color to it

Question 12

Describe the Lancefield test…

Answer 12

An unknown streptococcal species is heated or treated with an acid to destroy the protein antigens present. The cell wall carbohydrates present are used to place the streptococci into groups.

Question 13

Which Lacefield group has a capsule composed of hyaluronic acid?

Answer 13

Group A

Question 14

Within Group A stretococci, there is a capsule composed of hyaluronic acid. How does this work to protect the organism?

Answer 14

This mimics the host tissues, protecting the organism from phagocytosis

Question 15

What are the (5) toxins involved in streptococcus infections?

Answer 15

1. Streptolysin O
2. Streptolysin S
3. Streptokinase
4. DNase
5. Hyaluronidase

Question 16

What are the characteristics of Streptolysin O?

Answer 16

1. Very antigenic
2. Leukotoxic
3. Attacks RBCs (complete hemolysis)
4. Thiol-activated cytolysin
5. Oxidizable
6. Toxic to platelets & fibroblasts

Question 17

What are the characteristics of Streptolysin S?

Answer 17

1. Less toxic
2. Non-antigenic
3. Stable in O2

Question 18

Which Lancefield group is S. pyogenes a part of?

Answer 18

Group A

Question 19

What type of vaccine is available for S. pyogenes?

Answer 19

M-protein vaccine

Question 20

Which Lancefield group is S. equi a part of?

Answer 20

Group C

Question 21

Which strep species produce a mucoidal colony?

Answer 21

1. Strep equi
2. Strep zooepidemicus

Question 22

Which organism is an obligate parasite of Equidae?

Answer 22

Strep equi

Question 23

How can Strep equi be transmitted?

Answer 23

1. Contact
2. Fomites
3. Droplet

Question 24

Where on the body can Strep equi NORMALLY be found?

Answer 24

Horse: upper respiratory tract & reproductive tract

Question 25

1. Name 2 toxins of Strep equi. 2. What is their function?

Answer 25

1. M-protein * Antiphagocytic 2. Cytotoxin * Produces a cytotoxin that damages phagocytic cells

Question 26

Explain the disease progression of strangles in a horse. Do not forget to mention what the causitive agent is of this disease.

Answer 26

Strep equi starts an upper respiratory infection with a serous nasal discharge, which eventually turns purulent. Abscessation of the head and neck lymph nodes interferes with breathing and/or causes nerve damage. Animal can become septicemic and die.

Question 27

Explain the disease progression of Purpura. Do not forget to mention what the causitive agent is of this disease.

Answer 27

Strep equi causes this disease process. To begin, this disease is associated with a delayed immune response. The horse builds up high serum IgA titiers. The IgA forms immune complexes with the M-protein. These complexes cause many problems: fever, edema, hemorrhage, **vasculitis**, and **necrosis of blood vessel walls**.

Question 28

Which organism is most often associated with metritis in a horse?

Answer 28

Strep zooepidemicus

Question 29

The immunity following an infection with Strep equi is good. Why is this? What is providing this good immunity?

Answer 29

Protection against the infection is provided by **M-protein-specific IgA** on the surface of the **nasal epithelium**

Question 30

How might you treat an infection of Strep equi in a horse?

Answer 30

1. Penicillin 2. Lance abscess

Question 31

Which organism is the causitive agent of hemorrhagic pneumonia in dogs?

Answer 31

Strep zooepidemicus

Question 32

What types of disease can Strep equi cause in horses?

Answer 32

1. Purpura 2. Strangles 3. Reptroductive tract infections

Question 33

Which organism is most likely to be in a wound infection of a horse?

Answer 33

Strep zooepidemicus

Question 34

What are the natural habitats of Strep zooepidemicus?

Answer 34

1. Skin 2. Tonsillar/pharyngeal lymph nodes 3. Upper respiratory mucosa

Question 35

Which organism is associated with metritis and cervicitis in sows?

Answer 35

Strep equisimilis

Question 36

Which lancefield group is Strep equisimilis a part of?

Answer 36

Groups C, G, L

Question 37

Which lancefield group is Strep canis a part of?

Answer 37

Group G

Question 38

Which types of diseases can Strep canis cause in dogs?

Answer 38

1. Tonsillitis 2. Metritis 3. Umbilical infections 4. Septicemia 5. Wound infections

Question 39

What is are the (3) natural habitats of Strep uberis?

Answer 39

1. Skin 2. Bedding 3. GI tract