L14 ( Lecture numbers are wrong btw ) : streptococci

Question 1

what classification of bacteria is streptococci and how are they arranged ?

Answer 1

gram positive bacteria in chains

Question 2

how does streptoccoci react to :
coagulation test
catalase test

Answer 2

negative on both

Question 3

in what aerobic conditions do streptococci grow?

Answer 3

they are facultative anaerobes meaning they grow both in the presense of oxygen and in its absence

Question 4

bacteria are subdivided based on ___

Answer 4

C-carbohydrate antigen on their cell wall (A-U)

Question 5

which bacteria falls under group A Beta-hymolytic streptococci ?

Answer 5

S. pyogenes

Question 6

which bacteria falls under group B Beta-hemolytic streptococci ?

Answer 6

S. Agalacitae

Question 7

which streptococci species is responsible for 90% of pharyngitis cases?

Answer 7

S. pyogenes

Question 8

what component of S.pyogenes is responsible for inhibition of opsonization and cell lysis ?

Answer 8

M-protein

Question 9

which components of S. pyogenes are responsible for adhesion ?

Answer 9

lipoteichoic acid
factor F ( fibronectin binding proteins )

Question 10

which components of S.pyogenes are responsible for spread of organism through tissue ?

Answer 10

streptokinase
hyloronidase

Question 11

SPE-A + SPE-C Result in___

Answer 11

fever , and red rassh seen in scarlet fever

Question 12

SPE-A causes ____

Answer 12

toxic shock syndrome

Question 13

SPE-B is present in -

Answer 13

“flesh eating “ necrotizing fascites

Question 14

what cytolytic toxin of streptococci induces formation of anti-bodies?

Answer 14

Streptolysin O

Question 15

what cytolytic toxin of streptococci is responsible for hemolysis ?

Answer 15

Streptolysin S

Question 16

pathogenicity of S.pyogenes ::

Answer 16

pharyngitis
tonsillitis
sinusitis
otis media

cellulitis
necrosing fascitis
polydermal impetigo and eryspl—

Question 17

what is the most common strep disease?

Answer 17

strep/sore throat

Question 18

describe impetigo

Answer 18

honey colored crusts

Question 19

how is strep throat spread?

Answer 19

saliva / nasal secretions

Question 20

what is the incubation period of strep throat ?

Answer 20

2-4 days

Question 21

S. pyogenes also causes:
-endocardidits (puerperal fever )
-myositis
-acute rheumatic fever ( 2 weeks after infection )
-glomerulonephritis (2-3 weeks after infection )

Question 22

glomerulonephritis developed 2-3 weeks after s.pyogenes infection is an example of which type of hypersensitivity ?

Answer 22

type III hypersensitivity ( antibodies against streptolysin O )

Question 23

what lab test can differentiate S.pyogenes from S.agalactiae?

Answer 23

sensitivity test against bacitracin :

S.pyogenes is sensitive while S. agalactiae is resistant

Question 24

which streptococcal bacteria is part of normal flora of vagina and lower GIT ?

Answer 24

S. agalactiae (5-30% of women )

Question 25

what component protects S.agalactiae bacteria from phagocytosis ?

Answer 25

polysaccharide capsule

Question 26

pathogenicity of S. agalactiae ::

Answer 26

neonatal meningitis purperal sepsis pneumonia

Question 27

S. agalactiae is CAMP test ____

Answer 27

positive

Question 28

Group D streptococcal bacteria can be categorized into 2 groups , which are ?

Answer 28

enterococcus non-enterococcal

Question 29

examples of enterococcal bacteria :

Answer 29

S. fecalis S. faecium (UTI , intra-abdominal infections , pelvic infections ) they are normal flora in the GIT lower tract (opportunistic/ nosocomial infections )

Question 30

example of non enterococcal bacteria :

Answer 30

S. Bovis (S. gallocyticus)---causes endocarditis especially in patients with colon carcenoma

Question 31

Give examples if alpha hemolytic streptococcal bacteria .

Answer 31

S. pneumoniae S. viridans

Question 32

what's the shape /arrangement of S.pnumoniae ?

Answer 32

Lanceloale capsulated bicocci normal inhabitants of 5-40% of peoples upper resparatory tract

Question 33

give an example of a virulence factor of S. Pnumoniae .

Answer 33

IgA protease ( to protect itself since in enters through respiratory tract which contains a lot of secretions and therefore , IgA)

Question 34

Which streptococci could be non-hemolytic as well as alpha hemolytic ?

Answer 34

S. viridans

Question 35

where are S. VIRIDANS USUALLY FOUND IN NORMAL FLORA?

Answer 35

oral cavity and nasopharengeal flora

Question 36

what is the most common cause of sub-acute bacterial endocarditis >?

Answer 36

S. viridans

Question 37

which streptococci involves brain absesses ?

Answer 37

S. viridans and peptostreptococci

Question 38

which streptoccoci are involved in dental caries ?

Answer 38

S. viridans

Question 39

what lab test can differentiate between S. viridans and S. pnumoniae ?

Answer 39

sentitivity to optochin : S.. viridans are resistant while S.pnumoniae is sensitive

Question 40

give an example of an anaerobic streptoccoi ?

Answer 40

peptostreptococci ( grows in microarophillic conditions as well

Question 41

where are peptostreptococci normally present ?

Answer 41

normal flora of mouth , gut , and female genital tract