Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology > Exam 3 Streptococcus sp. > Flashcards

Exam 3 Streptococcus sp. Flashcards

(51 cards)

Start Studying
1
Q

What is the catalase test

A

the most important test to differentiate Gram positive Cocci: Staph from Strep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is indicative of a positive catalase test and a negative catalase test

A

positive=bubbles
negative=no bubbles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the results for a catalase of streptococcus and enterococcus species

A

they are catalase negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the characteristics of streptococcus and enterococcus species

A

they are gram positive cocci (in pains and chains) and have varying hemolytic patterns such as gamma, alpha, and beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is streptococcus’ drug of choice

A

penicillin, works by inhibiting bacterial cell wall synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are latex antigen detection

A

commercially available kits that allow for the rapid detection of the Lancefield classification in B-hemolytic streps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where are streptococcus normally found

A

in the pharynx, mouth, lower Gi tract, and vagina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Streptococcus can cause life-threatening infections when identified in sterile sites such as

A

blood, csf, other body fluids (pleural, pericardial, joint, and vitreous), bone, and vascular tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the Lancefield classification of strep pyogenes

A

group A streptococcus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When Strep A is plated on SBA, what type of hemolysis can be seen

A

a large well-defined area of b-hemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sensitivity to bacitracin is

A

‘A’ disk positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Resistance to bacitracin is

A

‘A’ disk negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Is Strep A sensitive or resistant to bacitracin

A

Strep A is sensitive to bacitracin making it ‘A’ disk positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Is group A strep pyr+ or -

A

pyr +

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which proteins give group A strep a virulence factor

A

M proteins blocks the binding of C3b (opsonization), and F protein both help with the adherence and invasion of the epithelial cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Streptolysin O

A

streptolysin O is a hemolysin virulence factor of Group A strep that destroys WBCs, platelets, RBCs, and other tissues (oxygen labile- destroyed by oxygen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is Streptolysin O detected on SBA

A

to detect streptolysin O SBA should be stabbed to force some of the organism to grow in a reduced oxygen content

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is Streptolysin S

A

streptolysin S is another hemolysin virulence factor of Group A strep that can lyse RBCs and WBCs (oxygen stabile-can grow in the presence of oxygen)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are some other virulence factors of Group A strep

A

hyaluronidase- a spreading factor that causes the breakdown of connective tissue

Streptokinase- lysis fibrin clots

Streptococcal pyrogenic exotoxins (SPEs)- causes a red spreading rash and acts as superantigens (SPE A,B,C, and F exotoxins)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are infections caused by Group A strep

A

pharyngitis (strep throat THE MOST COMMON CAUSED BY A STREP), pyoderma (skin infections), sepsis (blood infections), and necrotizing fasciitis (streptococcal gangrene)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are some pyoderma infections

Study These Flashcards
A

impetigo (in very young children), erysipelas (spreading red rash), and cellulitis (deep invasion of GAS leading to necrosis and gangrene)

22
Q

What are some complications that can happen post Group A infection

Study These Flashcards
A

Rheumatic fever (occurs after pharyngitis), scarlet fever, and acute glomerulonephritis

23
Q

What is the Lancefield classification of streptococcus agalactiae

Study These Flashcards
A

Group B strep

24
Q

What are some virulence factors of group B strep

Study These Flashcards
A

capsule, hemolysin, CAMP factor

25
Who are group B strep often associated with
neonates, 80% of cases are caused by vertical transmission from mother during birth premature birth, membrane rupture, pneumonia, and meningitis with bacterium can all be caused by Group B strep if mother is not treated during pregnancy
26
How is Group B strep detected
by a collection of a vaginal swab of pregnant women between 35 and 37 weeks
27
What type of media can Strep B be grown in
Todd Hewitt (LIM) broth with antimicrobials
28
What is the result of Group B catalase test
negative
29
What type of hemolysis does group B strep have
pin-point colonies with narrow zone of Beta Hemolysis
30
Is Group B strep sensitive or resistant to bacitracin
Group B is resistant to bacitracin- 'A' disk negative
31
Is Group B Camp test negative or positive
Camp test positive
32
Is Group B strep Hipp test positive or negative
Hipp test positive
33
What is the CAMP test
the Christie-Atkins-Munch-Petersen test is used to identify group B strep and differentiate it from other streptococci
34
What are some virulence factors of Streptococcus pneumoniae
a polysaccharide capsule, toxins such as hemolysins, IgA protease, neuraminidase, and hyaluronidase
35
What type of hemolysis does Strep pneumo have and what do the colonies look like
Strep Pneumo has a large well-defined area of alpha hemolysis, the colonies are umblicate with highly mucoid =, glistening colonies, older colonies have a collapsed center giving it the appearance of a penny/coin with a raised rim "water drop" colony
36
What type of infections do strep pnuemo cause
MOPS Meningitis, Otitis, Pneumonia (THE MOST COMMON), and Sinusitis
37
Where is strep pnuemo located
Strep Pnuemo is common as normal flora in the upper respiratory tract
38
What other infections can step pneumo be involved in
Endocarditis, Peritonitis, and Hemolytic uremic syndrome
39
What type of cocci is Strep pneumo
Gram positive diplococci
40
Is strep pneumonia Optochin resistant or sensitive
It is optochin sensitive making it 'P' disk positive
41
Is strep pnuemo Bile + or -
It is bile +
42
How can the strep pneumo capsule be seen
with a quelling reaction
43
What is a common occurrence of Strep Pneumo
Rust colored sputum
44
How is strep pneumo screened for penicllin
an oxacillin disc is used to screen for penicillin sensitivity >20mm=sensitive
45
Is there a vaccine for strep pneumo
there is a vaccine for strep pneumo called a polyvalent vaccine & it is recommended for children under 2 years old
46
What is Group D streptococcus
Group D is strep Bovis and equinus and it is known as the SBSE complex
47
What type of hemolysis does Group D strep have
Alpha, beta, and gamma hemolysis
48
Is Group D strep resistant or sensitive to optochin
Group D strep is resistant to optochin making it 'P' disk negative
49
Is Group D strep bile esculin + or -
it is BE +
50
Is Group D strep 6.5% NaCl - or +
no growth at 6.5% making it 6.5% NaCl negative
51
Is Group D resistant or sensitive to penicillin
sensitive to penicillin which makes it different from enterococcus species

Microbiology (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions