Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbiology - Bacteria > Gram-positive bacteria - lab algorithm > Flashcards

Gram-positive bacteria - lab algorithm Flashcards

0
Q

What are 2 tests to differentiate between the Gram-positive cocci?

A

1) appearance on Gram stain: Streptococci appear as chains(strips), and Staphylocci appear as clusters
2) catalase: Streptococci is catalase-negative, Staphyloccus is catalase-positive

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

What are the Gram-positive cocci?

A

1) Streptococcus (and Enterococcus)

2) Staphlycoccus

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

How to differentiate between Gram-positive cocci based on morphology?

A

Streptococci appear as chains(strips)

Staphylococci appear as clusters

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

How to differentiate between Gram-positive cocci based on catalase test?

A

Streptococci are catalase-negative.

Staphylococci are catalase-positive.

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

Streptococci are classified according to what ability?

A

hemolysis

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

alpha hemolytic - defn

A

partially lyse RBCs (on blood agar) leaving a greenish discoloration of the culture medium surrounding the colony (which contains unlysed RBCs and a green-colored metabolite of hemoglobin)

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

What type of hemolysis partially lyses RBCs and leaves a greenish discoloration of blood agar?

A

alpha hemolysis

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

beta hemolysis - defn

A

completely lyses RBCs, leaving a clear zone of hemolysis around the colony on blood agar

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

What type of hemolysis completely lyses RBCs and leaves a clear zone surrounding the colony?

A

beta hemolysis

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

gamma hemolysis - defn

A

non-hemolytic

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

What type of hemolysis is non-hemolytic (unable to lyse RBCs)?

A

gamma-hemolytic

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

What bacteria are alpha hemolytic when grown on blood agar? (2)

A

1) Streptococcus pneumoniae

2) Viridans streptococcus

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

S. pneumoniae displays what type of hemolysis when grown on blood agar?

A 
alpha hemolytic (partial hemolysis)
Streptococci pneumoniae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

S. viridans displays what type of hemolysis when grown on blood agar?

A 
alpha hemolysis (partial hemolysis)
Streptococci viridans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What streptococci display beta hemolysis when grown on blood agar?

A

1) Group A Streptococcus (S. pyogenes)

2) Group B Streptococcus (S. agalactiae)

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

Group A strep displays what kind of hemolysis when grown on blood agar?

A

beta (complete) hemolysis

Group A = Strep pyogenes

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

S. pyogenes displays what kind of hemolysis when grown on blood agar?

A

beta (complete) hemolysis

Streptococci pyogenes = Group A strep

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

Group B streptococci display what type of hemolysis when grown on blood agar?

A

beta (complete) hemolysis

Group B strep = Streptococci agalactiae

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

S. agalactiae displays what kind of hemolysis when grown on blood agar?

A

beta (complete) hemolysis

Streptococci agalactiae = Group B strep

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

What streptococci are gamma-hemolytic? (2)

A

Group D strep: Enterococci and Nonenterococci

gamma hemolytic = non hemolytic

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

Group D streptococci display what type of hemolysis when grown on blood agar?

A

gamma-hemolytic (non-hemolytic)

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

What type of streptococci are non-hemolytic?

A

Group D strep: enterococcus, nonenterococcus

Gamma hemolytic = non-hemolytic

22
Q

Which two antibiotics can differentiate among species of streptococci?

A

1) optochin

2) bacitracin

23
Q

Optocochin is used to differentiate among which type of hemolytic streptococci?

A

alpha-hemolytic

24
The alpha-hemolytic streptococci are differentiated based on sensitivity to which antibiotic?
optocochin
25
Optochin is used to differentiate among which bacteria?
Streptococci alpha hemolytics: S.pneumoniae and S. viridans S. viridans is resistant S. pneumo is sensitive "OVRPS" (overpass)
26
S. pneumoniae is (sensitive, resistant) to optochin
sensitive | "OVRPS"
27
Which alpha hemolytic streptococcus is optochin sensitive?
S. pneumoniae | "OVRPS"
28
Which alpha hemolytic streptococcus is optochin resistant?
S. viridans | "OVRPS"
29
S. viridans is (sensitive, resistant) to optochin.
resistant | "OVRPS"
30
The alpha hemolytic streptococci can be differentiated based on what 3 characteristics?
1) capsule (S. pneumo has capsule; S. viridans does not) 2) optochin (S. pneumo is sensitive; S. viridans is resistant) 3) bile (S. pneumo is lysed by (soluble in) bile; S. viridans is bile insoluble)
31
How can alpha hemolytic streptococci be differentiated based on presence or absence of a capsule?
S. pneumoniae has a capsule | S. viridans does not have a capsule
32
How can alpha hemolytic streptococci be differentiated based on bile solubility?
S. pneumoniae is bile soluble (lysed by bile). | S. viridans is bile insoluble (not lysed by bile).
33
Bacitracin is used to differentiate among which type of hemolytic streptococci?
beta-hemolytic (complete hemolysis)
34
The beta-hemolytic streptococci are differentiated based on sensitivity to which antibiotic?
bacitracin
35
Bacitracin is used to differentiate among what bacteria?
Streptococci beta (complete) hemolytics: S.pyogenes (Group A strep) and S.agalactiae (Group B strep) Group B strep are resistant Group A strep are sensitive "B-BRAS"
36
Group A strep is bacitracin (sensitive, resistant)
sensitive | B-BRAS
37
S. pyogenes is bacitracin (sensitive, resistant)
sensitive S. pyogenes = Group A strep B-BRAS
38
Group B strep is bacitracin (sensitive, resistant)
resistant | B-BRAS
39
S. agalactiae is bacitracin (sensitive, resistant)
resistant S. agalactiae = Group B strep "B-BRAS"
40
Which beta-hemolytic streptococcus is bacitracin sensitive?
Group A strep (S. pyogenes) | B-BRAS
41
Which beta-hemolytic streptococcus is bacitracin resistant?
Group B strep (S. agalactiae) | "B-BRAS"
42
The gamma-hemolytic streptococci can be differentiated based on growth in what media?
bile +/- NaCl Group D enterococci grow in bile and 6.5% NaCl Non-enterococci grow in bile, but not in 6.5% NaCl
43
The Group D streptococci can be differentiated based on growth in what media?
bile +/- NaCl Group D enterococci grow in bile and 6.5% NaCl Non-enterococci grow in bile, but not in 6.5% NaCl
44
Bile +/- 6.5% NaCl is used to differentiate among what type of bacteria?
Gamma(non)-hemolytic streptococci Group D enterococci grow in bile and 6.5% NaCl Non-enterococci grow in bile, but not in 6.5% NaCl
45
Which gamma-hemolytic bacteria grow in bile and 6.5% NaCl?
Group D strep (enterococci) | E. faecalis and E. faecium
46
Which gamma-hemolytic bacteria grow in bile but not 6.5% NaCl?
Group D strep - nonenterococci | S. bovis and S. equinus
47
Which bacteria are alpha-hemolytic? (2)
1) Streptococcus pneumoniae | 2) Streptococcus viridans
48
Which bacteria are beta-hemolytic? (4)
1) Staphylococcus aureus 2) Group A strep (Streptococcus pyogenes) 3) Group B strep (Streptococcus agalactiae) 4) Listeria monocytogenes
49
``` What bacteria is: blue on Gram stain cocci in chains negative catalase test forms green ring around colonies when grown on blood agar optochin sensitive ```
Streptococcus pneumoniae
50
``` What bacteria is: blue on Gram stain cocci in chains negative catalase test forms green ring around colonies when grown on blood agar optochin resistant ```
Streptococcus viridans
51
``` What bacteria is: blue on Gram stain cocci in chains negative catalase test forms clear area around colonies when grown on blood agar bacitracin sensitive ```
Streptococcus pyogenes
52
``` What bacteria is: blue on Gram stain cocci in chains negative catalase test forms clear area around colonies when grown on blood agar bacitracin resistant ```
Streptococcus agalactiae
53
``` What bacteria is: blue on Gram stain cocci in clusters positive catalase test forms clear area around colonies when grown on blood agar positive coagulase test ```
Staphylococcus aureus

Microbiology - Bacteria (15 decks)

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