(1/22/15) Streptococci (Bailey) Flashcards Preview

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Flashcards in (1/22/15) Streptococci (Bailey) Deck (47):
1

streptococcus sp. is a gram ____ cocci that is composed of chains and is non-_____ forming. it is a _____ ____ and catalase (test) ______

-positive
-spore
-facultative anaerobe
-negative

2

what are the three ways to classify streptococcus?

-hemolysis pattern
-lancefield group
-species (often not necessary)

3

hemolysis pattern that has partial hemolysis and green discoloration of hemoglobin

alpha

4

hemolysis pattern that shows a clear zone of COMPLETE hemolysis

beta

5

hemolysis pattern that has NO zone of clearing

gamma

6

what group of Beta hemolysis streptococci is responsible for causing the most human diseases

A

7

acute pharyngitis, pyoderma, streptococcal pneumonia, necrotizing fascitis, childbed fever, and foodborne outbreaks are all characteristics of which group of streptococcal diseases

A

8

the S progenies in group A streptococci (GAS) are responsible for what two diseases?

-streptococcal acute pharyngitis (strep throat)
-scarlet fever (strep throat + red skin rash)

9

fever that was fairly common until the mid-20th century and is rarely seen in developed countries now. the US outbreaks in the 80's and 90's were due to the emergence of virulent strains

Acute Rheumatic Fever

10

where is the only site of infection that is followed by Acute Rheumatic Fever (1-4 weeks past strep throat)

pharynx

11

in reference to acute rheumatic fever, infection must invoke _____ response

immune
-(could be considered an auto immune disease)(no more than 10% of ppl are susceptible)

12

you can completely prevent acute rheumatic fever infection by treating strep throat with a full course of _____

penicillin

13

actue rheumatic fever has a high susceptibility to recurrence, thus ______ antibiotics into adulthood or for life

prophylactic

14

active inflammation in the glomeruli of the kidney that turns urine smokey due to proteins, leukocytes and erythrocytes, and renal failure (dialysis)

acute post-streptococcal glomerulonephritis

15

what are four ways that acute post-streptococcal glomerulonephritis is different that acute rheumatic fever?

unlike ARF
-can follow pharyngitis or pyodermal infections
-susceptibility common
-recurrent attacks are rare
-not reliably prevented by penicillin

16

what ages do not get strep throat?

1-2 year olds

17

____ % of school aged children may carry Group A infections without symptoms

20

18

what two ways does a person encounter group A infections?

-live on the skin and mucous membranes
-person to person transmission (respiratory drops, hand to hand, food, skin wounds....)

19

Group A infections CANNOT penetrate ____ ____

intact skin (enter through bites, wounds, lesions, cuts, abrasions....)

20

in group A infections, bacteria bind to epithelial cells using _____

adhesions

21

what are the three types of adhesions that group A bacteria use?

-lipoteichoic acid (LTA)
-protein F
-M protein

22

type of group A infection adhesion that makes the streptococci sticky and then binds to fibronectin on epithelial cell surfaces

lipoteichoic acid (LTA)

23

type of group A infection adhesion that is a high affinity fibronectin binding protein

protein F

24

type of group A infection adhesion that is a keratinocyte (outer skin) adhesion

M protein

25

what does the spread of a group A infection depend on?

how the infection was acquired

26

if a group A infection was acquired on the skin or mucous membranes, it usually _____ ____

remains localized

27

if a group A infection was acquired through deeper tissue infections then there is _____ ____

rapid spread

28

_____ is an enzyme that binds to the inactive host plasminogen to create a catalytic complex that breaks down fibrin (blood clots)

streptokinase

29

what are three things that aid group A bacteria in avoiding phagocytosis

-M proteins (most important antiphagocytic factor)
-hyaluronic acid capsule
-C5a peptidase

30

used by bacteria to avoid phagocytosis, is the most important antiphagocytic factor and is required for virulence

M proteins

31

used by bacteria to avoid phagocytosis, is a mucoid capsule and makes the strep slippery, interfering with phagocyte attachment

hyaluronic acid capsule

32

used by bacteria to avoid phagocytosis, it inactivates phagocyte chemotaxin

C5a Peptidase

33

forms a dense coating on bacteria's surface and blocks complement from binding to the cells. it then binds the host complement control proteins

M proteins

34

super antigens that activate macrophages and cause T cells to release cytokines (three types: SpeA, SpeB, SpeC)

streptococcal pyrogenic exotoxins (SPE's)

35

the super antigens of streptococcal pyrogenic exotoxins (SPE's) are responsible for what two things?

-red rash of scarlet fever
-streptococcal toxic shock syndrome

36

Group that is actually more common but less notorious than group A streptococci

B

37

Group B strep inhabit _____ ____ and female _____ ____ and are the leading cause of _____ _______ and _______

-lower GI
-genital tracts
-neonatal sepsis
-menigitis

38

group B bacteria use what type of capsule?

polysaccharide

39

what are three similarities between group A strep and the other group strep?

-M proteins
-bind fibrinogen
-secrete similar extracellular enzymes

40

Group of strep that is normal flora of GI and genitourinary tracts. has a low virulence and usually accompanies other bacterial infections

D

41

"world's toughest pathogenic bacteria" that grows in high salt concentrations and in bile. is resistant to most antibiotics including penicillin

enterococci

42

_____ _____ is required for effective killing of enterococci

antibiotic synergism (usually between penicillin and aminoglycoside)

43

makes up 30-60% of the oropharyngeal flora, has a low virulence, but is the most common cause of subacute bacterial endocartidis (affects abnormal heart valves) AND IS RESPONSIBLE FOR DENTAL CARIES (mutan group)

viridians Streptococci

44

viridians streptococci produce ____ for adherence

dextrans

45

the surface proteins of viridans streptococci "mutans group" bind salivary _____ on teeth

glycoproteins

46

amounts to ~50% or more of bacteria in plaque

viridians streptococci "mutans group"

47

the viridian's streptococci "mutans group" ferments sugar to ____ ____ which demineralizes the enamel

lactic acid