Ch 3 : Streptococci

Question 1

Faculative anaerobic , nonmotils , arranged in long chain

Answer 1

Streptococci

Question 2

How many species to streptococci?

And how is dying?

Answer 2

25 s

By heat

Question 3

Classification of streptococci?

Answer 3

1 _ lancefield classification system based on cell wall _ 17 groups (A,B,c…)

2_ another classification system based on hemolysis reactions

Question 4

Hunam streptococcal pathogen? And the important type is?

Answer 4

_ s . Pyogene
_ s . Agalactiae
_ s . Pneumoniae
_ viridans streptococci
_ Entrococcus faecalis

_s. pyogene

Question 5

Strict parasite طفيلي اجباري

Inhabits throat , nasopharynx , skin

Answer 5

B_hemolytic s.pyogenes

Question 6

Virulence factor of b-hemolytic s.pyogenes? (Produce surface antigens)

Answer 6

1- c-carbohydrate : protect against lysozomal
2- fimbriae : adherence to surface
3_ M-protein : contributes to resistance to phagocytosis
4_hyaluronic acid capsule : provokes no immune response ( not visible)

Question 7

Virulence factor of b-hemolytic s.pyogenes? (Extracellular toxin)

Answer 7

1-streptolysins : hemolysins :
- streptolysins o (oxygen lable) SLO
- streptolysins S (oxygen stable) SLS
2_pyogenic toxin : 
-induced fever and typical skin red rash
3_ superantigens:
Strong monocyte and lymphocye stimulate.

Question 8

Virulence factor of b-hemolytic s.pyogenes? (Extarcellualar Enzyme)

Answer 8

1- strptokinase : digest fibrin clots
2-hyaluronidase : break dwon connective tissue
3- DNase: hydrolyse DNA

Question 9

Scope of clinical disease?

-skin infection

Answer 9

1- impetigo : occur in school childern

2- Erysipelas : pathogen enters throuhg a break in the skin

Question 10

Scope of clinical disease?

Throat infection:

Answer 10

1- streptococcal pharyngitis:
strep throat
2-Necrotizing fasciitis:
Flesh-Eatinf strep

Question 11

Scope of clinical disease?

Systemic infections :

Answer 11

1- scarlet fever : strain of s.pyogenes 
2-septicemia : (blood poisoning , especiall than cased by bacteria )
3-pneumonia : lung infection 
4- streptococaal toxic shock syndrome :
 organ failure

Question 12

Long term complication of group A ? Cronic

المضاعفات الطويلة المدى؟

Answer 12

1-rheumatic fever : overt

2-acute glomerulnephritis :nephritis

Question 13

Regularly resides in human vagina, pharynx and large intestine

المهبل البشري

Answer 13

Agalactiae

Question 14

Type of streptococcus ?

Answer 14

1 a-hemolytic :
 green ,partical hemolysis
2 B-hemolytic :
 clear, complete hemolysis
3 y-hemolytic :
 no hemolysis

Question 15

What is the name of bacterial species used together with Streptococci in CAMP test? ما هو اسم الأنواع البكتيرية المستخدمة مع المكورات العقدية في اختبار CAMP؟

Answer 15

S.pyogenes

Question 16

a-hemolytic streptococci: viridans group : large complex group

M o s s m m

Answer 16

Streptococcus mutans
S.oralis
S.salivarue
S.sanguis 
S.milleri
S.mitis

Question 17

produce slime layers that adhere to teeth, basis for plaque?

Answer 17

S.mutans

يموت انس بالاسنان

Question 18

Streptococci genral characteristics:

Answer 18

1_ Gram positive cocci in chains( short or long) and pairs
2_ catalase negative
3- grow on blood agar
4- usually sensitive to penicillic