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Microbiology 386 > Streptococcus > Flashcards

Flashcards in Streptococcus Deck (43):
1

  1. Are staphs catalase + or -?
  2. Are streps catalase + or -?

  1. Staphs are catalse +
  2. Streps are catalase -

2

What change in the RBCs contributes to alpha hemolysis?

RBCs are still present in the media but the hemoglobin has been changed to methemoglobin

3

  1. What are the groups used to group the streptococci?
  2. How are they grouped?

  1. Lancefield groups
  2. Cell wall carbohydrates

4

Streptococcus capsule:

Important with some streptococcual groups, especially ____ which have a capsule composed of ____ ____.  This not only masks the organism but mimics ____ ____.  Protects from ____.

Streptococcus capsule:

Important with some streptococcal groups, especially group A which have a capsule composed of hyaluronic acid.  This not only masks the organism but mimics host tissues.  Protects from phagocytosis.

5

List 5 toxins of Streptococcal species:

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

6

What toxin is being described?

Leukotoxin

Attacks RBCs

Causes complete hemolysis

Toxic to platelets and fibroblasts

Very antigenic

Streptolysin-O

7

Which toxin is being described?

Less toxic

Non-antigenic

Produces the hemolysis that is usually seen

Streptolysin-S

8

Which toxin is being described?

In addition to lysing fibrin, this enzyme is able to cleave C3.

Streptokinase

(fibrinolysin)

9

All strains of Group A streptococci produce at least one ___ that assists in ____.

All strains of Group A streptococci produce at least one nuclease that assists in liquefaction of pus and obtaining nutrients.

10

Hyaluronidase breaks down ____ ____ in tissues and is considered to be a ____ ____.

Hyaluronidase breaks down hyaluronic acid in tissues and is considered to be a spreading factor.

11

Group A streptococcus is synonymous with what?

Strep pyogenes

12

  1. What is the natural habitat of strep pyogenes?
  2. True or False: most children have been infected with this organism by the time they are 10.
  3. True or False: different M-protein types tend to circulate through susceptible populations.

  1. Human pharyngeal and tonsillar areas
  2. TRUE
  3. TRUE

 

13

What is the major virulence facotr of Group A streptococci?

M-proteins

14

What does Group A strep cause in humans?

Strep throat

Scarlet fever

Sinusitis

Heart valve lesions

Glomerulonephritis

Rheumatic fever

Erysipelas

Necrotizing fasciitis

15

What toxins produce the rash and fever in scarlet fever?

Erythrogenic toxins

16

Which organism(s) is/are in lancefield group C?

Strep equi subspecies equi

Strep equi subspecies zooepidemicus

17

How is strep equi transmitted from horse to horse?

Fomite

Contact

Droplet

18

Where is Strep equis habitat?

Horse upper respiratory tract and reproductive tract

19

From the respiratory tract, how does strep equi cause disease in a horse?

In the respiratory tract, the organism enters through the nasal epithelial cells and tonsils and travels via the lymph to the submandibular and other lymph nodes of the head and neck.

20

Which virulence factor is part of strep equi and serves an antiphagocytic purpose?

M-protein

21

Which is the most common cause of metritis in horses?

Strep zooepidemicus

22

What has been responsible for recent outbreaks of hemorrhagic pneumonia is dogs?

Strep zooepidemicus

23

What is the cause of "alpaca fever" in South America?

Strep zooepidemicus

24

What is the natural habitat of strep zooepidemicus?

Skin

Upper respiratory mucosa

Tonsillar & phyarngyeal lymphoid tissues

25

What is the most common cause of wound infections in horses?

Strep zooepidemicus

26

What is the most common cause of uterine and cervical infections in mares?

Strep zooepidemicus

27

What is associated with metritis and cervicitis in sows?

Strep equisimilis

28

What else does Strep equisimilis cause?

Suppurative arthritis in pigs

Vegetative valvular endocarditis

Repro tract infections in dogs

29

What makes up lancefield group G?

Strep canis

30

Name 3 conditions strep canis causes in dogs.

(There are 5)

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

31

What is the natural habitat of strep canis?

Male dog genital tract

32

What is strep canis most likely to cause in cats?

Wound infections

33

What makes up lancefield group E?

Strep porcinus

34

What conditions does strep porcinus cause?

Jowl abscesses in pigs

Genitourinary infections in women

35

What lancefield group is Strep suis?

Group D

36

What are the 3 virulence factors for strep suis?

Muramidase released protein

Extracellular protein factor

Suilysin

37

What is suilysin?

A cholesterol-binding hemolysin

38

How does strep suis enter into the body of say a human being?

Cuts

Abrasions

Conjunctiva

39

Which age of pig does strep suis affect?

Young pigs:

At birth OR shortly after

40

What types of disease does strep suis cause in piglets?

Meningitis

Arthritis

Septicemia

Bronchopneumonia

41

What diseases does strep suis cause in human beings?

Meningitis

Pneumonia

Arthritis

Endocarditis

Toxic shock syndrome

Hearing loss

42

Which lancefield group is strep dysgalactiae in?

Group C

43

Camp test for :

Strep agalactiae?

Strep dysgalactiae?

Strep uberis?

Strep agalactiae (+)

Strep dysgalactiae (-)

Strep uberis (15% +)