Micro-Gram-Positive and Gram-Negative Cocci Flashcards
1
Q
- The test used most often to separate the
Micrococcaceae family from the Streptococcaceae
family is:
A. Bacitracin
B. Catalase
C. Hemolysis pattern
D. All of these options
A
B. Catalase
2
Q
- Micrococcus and Staphylococcus species are
differentiated by which test(s)?
A. Fermentation of glucose (OF tube)
B. Catalase test
C. Gram stain
D. All of these options
A
A. Fermentation of glucose (OF tube)
3
Q
- Lysostaphin is used to differentiate Staphylococcus
from which other genus?
A. Streptococcus
B. Stomatococcus
C. Micrococcus
D. Planococcus
A
C. Micrococcus
4
Q
- Which of the following tests is used routinely to
identify Staphylococcus aureus?
A. Slide coagulase test
B. Tube coagulase test
C. Latex agglutination
D. All of these options
A
D. All of these options
5
Q
- Which of the following enzymes contribute to the
virulence of S. aureus?
A. Urease and lecithinase
B. Hyaluronidase and β-lactamase
C. Lecithinase and catalase
D. Cytochrome oxidase
A
B. Hyaluronidase and β-lactamase
6
Q
- Toxic shock syndrome is attributed to
infection with:
A. Staphylococcus epidermidis
B. Staphylococcus hominis
C. Staphylococcus aureus
D. Staphylococcus saprophyticus
A
C. Staphylococcus aureus
7
Q
- Which Staphylococcus species, in addition to
S. aureus, also produces coagulase?
A. S. intermedius
B. S. saprophyticus
C. S. hominis
D. All of these options
A
A. S. intermedius
8
Q
- Staphylococcus epidermidis (coagulase negative) is
recovered from which of the following sources?
A. Prosthetic heart valves
B. Intravenous catheters
C. Urinary tract
D. All of these options
A
D. All of these options
9
Q
- Slime production is associated with which
Staphylococcus species?
A. S. aureus
B. S. epidermidis
C. S. intermedius
D. S. saprophyticus
A
B. S. epidermidis
10
Q
- Strains of Staphylococcus species resistant to the
β-lactam antibiotics by standardized disk diffusion
and broth microdilution susceptibility methods
are called:
A. Heteroresistant
B. Bacteriophage group 52A
C. Cross resistant
D. Plasmid altered
A
A. Heteroresistant
11
Q
- Staphylococcus saprophyticus is best differentiated
from Staphylococcus epidermidis by resistance to:
A. 5 μg of lysostaphin
B. 5 μg of novobiocin
C. 10 units of penicillin
D. 0.04 unit of bacitracin
A
B. 5 μg of novobiocin
12
Q
- The following results were observed by using a
tube coagulase test:
Coagulase at 4 hours = + Coagulase at 18 hours = Neg
DNase = +
Novobiocin = Sensitive
(16-mm zone)
Hemolysis on blood : agar = β
Mannitol salt plate = +(acid production)
What is the most probable identification?
A. Staphylococcus saprophyticus
B. Staphylococcus epidermidis
C. Staphylococcus aureus
D. Staphylococcus hominis
A
C. Staphylococcus aureus
13
Q
- Staphylococcus aureus recovered from a wound
culture gave the following antibiotic sensitivity
pattern by the standardized Kirby–Bauer method
(S = sensitive; R = resistant):
Penicillin = R
Ampicillin = S
Cephalothin = R
Cefoxitin = R
Vancomycin = S
Methicillin = R
Which is the drug of choice for treating this
infection?
A. Penicillin
B. Ampicillin
C. Cephalothin
D. Vancomycin
A
D. Vancomycin
14
Q
- Which of the following tests should be used to
differentiate Staphylococcus aureus from
Staphylococcus intermedius?
A. Acetoin
B. Catalase
C. Slide coagulase test
D. Urease
A
A. Acetoin
15
Q
- A gram-positive coccus recovered from a wound
ulcer from a 31-year-old diabetic patient showed
pale yellow, creamy, β-hemolytic colonies on
blood agar. Given the following test results, what
is the most likely identification?
Catalase = +
Glucose OF: positive open tube, negative sealed tube
Mannitol salt = Neg
Slide coagulase = Neg
A. Staphylococcus aureus
B. Staphylococcus epidermidis
C. Micrococcus spp.
D. Streptococcus spp.
A
C. Micrococcus spp.
16
Q
- Urine cultured from the catheter of an 18-year-old
female patient produced more than 100,000 col/mL
on a CNA plate. Colonies were catalase positive,
coagulase negative by the latex agglutination slide
method as well as the tube coagulase test. The best
single test for identification is:
A. Lactose fermentation
B. Urease
C. Catalase
D. Novobiocin susceptibility
A
D. Novobiocin susceptibility
17
Q
- A Staphylococcus spp. recovered from a wound
(cellulitis) was negative for the slide coagulase test
(clumping factor) and negative for novobiocin
resistance. The next test(s) needed for
identification is (are):
A. Tube coagulase test
B. β-Hemolysis on blood agar
C. Mannitol salt agar plate
D. All of these options
A
D. All of these options
18
Q
- Furazolidone (Furoxone) susceptibility is a test
used to differentiate:
A. Staphylococcus spp. from Micrococcus spp.
B. Streptococcus spp. from Staphylococcus spp.
C. Staphylococcus spp. from Pseudomonas spp.
D. Streptococcus spp. from Micrococcus spp.
A
A. Staphylococcus spp. from Micrococcus spp.
19
Q
- Bacitracin resistance (0.04 unit) is used to
differentiate:
A. Micrococcus spp. from Staphylococcus spp.
B. Staphylococcus spp. from Neisseria spp.
C. Planococcus spp. from Micrococcus spp.
D. Staphylococcus spp. from Streptococcus spp.
A
A. Micrococcus spp. from Staphylococcus spp.
20
Q
- Which of the following tests will rapidly
differentiate micrococci from staphylococci?
A. Catalase
B. Coagulase
C. Modified oxidase
D. Novobiocin susceptibility
A
C. Modified oxidase
21
Q
- Streptococcus species exhibit which of the following
properties?
A. Aerobic, oxidase positive, and catalase positive
B. Facultative anaerobe, oxidase negative, catalase
negative
C. Facultative anaerobe, β-hemolytic, catalase
positive
D. May be α-, β-, or γ-hemolytic, catalase positive
A
B. Facultative anaerobe, oxidase negative, catalase
negative
22
Q
- Which group of streptococci is associated with
erythrogenic toxin production?
A. Group A
B. Group B
C. Group C
D. Group G
A
A. Group A
23
Q
- A fourfold rise in titer of which antibody is the
best indicator of a recent infection with group A
β-hemolytic streptococci?
A. Anti-streptolysin O
B. Anti-streptolysin S
C. Anti-A
D. Anti-B
A
A. Anti-streptolysin O
24
Q
- Bacitracin A disks (0.04 unit) are used for the
presumptive identification of which group of
β-hemolytic streptococci?
A. Group A
B. Group B
C. Group C
D. Group F
A
A. Group A
25
Q
- Trimethoprim–sulfamethoxazole (SXT) disks are
used along with bacitracin disks to differentiate
which streptococci?
A. α-Hemolytic streptococci
B. β-Hemolytic streptococci
C. Streptococcus pneumoniae
D. Enterococcus faecalis
A
B. β-Hemolytic streptococci
26
Q
- β-Hemolytic streptococci, not of group A or B,
usually exhibit which of the following reactions?
A
D.
27
Q
- A false-positive CAMP test for the presumptive
identification of group B streptococci may occur
if the plate is incubated in a(n):
A. Candle jar or CO2 incubator
B. Ambient air incubator
C. 35°C incubator
D. 37°C incubator
A
A. Candle jar or CO2 incubator
28
Q
- Which test is used to differentiate the viridans
streptococci from the group D streptococci and
enterococci?
A. Bacitracin disk test
B. CAMP test
C. Hippurate hydrolysis test
D. Bile esculin test
A
D. Bile esculin test
29
Q
- The bile solubility test causes the lysis of:
A. Streptococcus bovis colonies on a blood agar plate
B. Streptococcus pneumoniae colonies on a blood
agar plate
C. Group A streptococci in broth culture
D. Group B streptococci in broth culture
A
B. Streptococcus pneumoniae colonies on a blood
agar plate
30
Q
- S. pneumoniae and the viridans streptococci can be
differentiated by which test?
A. Optochin disk test, 5 μg/mL or less
B. Bacitracin disk test, 0.04 unit
C. CAMP test
D. Bile esculin test
A
A. Optochin disk test, 5 μg/mL or less
31
Q
- The salt tolerance test (6.5% salt broth) is used to
presumptively identify:
A. Streptococcus pneumoniae
B. Streptococcus bovis
C. Streptococcus equinus
D. Enterococcus faecalis
A
D. Enterococcus faecalis
32
Q
- In addition to Enterococcus faecalis, which other
streptococci will grow in 6.5% salt broth?
A. Group A streptococci
B. Group B streptococci
C. Streptococcus pneumoniae
D. Group D streptococci (nonenterococci)
A
B. Group B streptococci
33
Q
- The quellung test is used to identify which
Streptococcus species?
A. S. pyogenes
B. S. agalactiae
C. S. sanguis
D. S. pneumoniae
A
D. S. pneumoniae
34
Q
- The L-pyrrolidonyl-β-napthylamide (PYR)
hydrolysis test is a presumptive test for which
streptococci?
A. Group A and D (enterococcus) streptococci
B. Group A and B β-hemolytic streptococci
C. Nongroup A or B β-hemolytic streptococci
D. Streptococcus pneumoniae and group D
streptococci (nonenterococcus
A
A. Group A and D (enterococcus) streptococci
35
Q
- A pure culture of β-hemolytic streptococci
recovered from a leg wound ulcer gave the
following reactions:
CAMP test = Neg
Hippurate hydrolysis = Neg
Bile esculin = Neg
6.5% salt = Neg
PYR = Neg
Bacitracin = Resistant
Optochin = Resistant
SXT = Sensitive
The most likely identification is:
A. Group A streptococci
B. Group B streptococci
C. Enterococcus faecalis
D. Nongroup A, nongroup B, nongroup D
streptococci
A
D. Nongroup A, nongroup B, nongroup D
streptococci
36
Q
- β-Hemolytic streptococci, more than 50,000 col/mL,
were isolated from a urinary tract catheter urine
specimen. Given the following reactions, what is the
most likely identification?
CAMP test = Neg
Hippurate hydrolysis = ±
Bile solubility = Neg
6.5% salt = +
PYR = +
Bile esculin = +
SXT = Resistant
Bacitracin = Resistant
Optochin = Resistant
A. Group A streptococci
B. Group B streptococci
C. Enterococcus faecalis
D. Nongroup A, nongroup B, nongroup D
streptococci
A
C. Enterococcus faecalis
37
Q
- Nutritionally variant streptococci (NVS) require
specific thiol compounds, cysteine, or the active
form of vitamin B6. Which of the following tests
supplies these requirements?
A. CAMP test
B. Bacitracin susceptibility test
C. Bile solubility test
D. Staphylococcal cross-streak test
A
D. Staphylococcal cross-streak test
38
Q
- Many α-hemolytic streptococci recovered from a
wound were found to be penicillin resistant. Given
the following results, what is the most likely
identification?
Bile esculin = +
PYR = +
6.5% salt = +
Hippurate
Bile solubility= Neg
hydrolysis = +
SXT = Resistant
A. Enterococcus faecalis
B. Streptococcus pneumoniae
C. Streptococcus bovis
D. Group B streptococci
A
A. Enterococcus faecalis
39
Q
- Which two tests best differentiate S. bovis
(group D, nonenterococcus) from Streptococcus
salivarius?
A. Bile esculin and 6.5% salt broth
B. Starch hydrolysis and acid production from
mannitol
C. Bacitracin and PYR
D. Trimethoprim–sulfamethoxazole susceptibility
and PYR
A
B. Starch hydrolysis and acid production from
mannitol
40
Q
- Two blood cultures on a newborn grew β-hemolytic
streptococci with the following reactions:
CAMP test = +
Hippurate hydrolysis = +
Bile solubility = Neg
6.5% salt = +
Bacitracin = Resistant
Bile esculin = Neg
PYR = Neg
Trimethoprim–sulfamethoxazole = Resistant
Which is the most likely identification?
A. Group A streptococci
B. Group B streptococci
C. Group D streptococci
D. Nongroup A, nongroup B, nongroup D
streptococci
A
B. Group B streptococci
41
Q
- MTM medium is used primarily for the selective
recovery of which organism from genital
specimens?
A. Neisseria gonorrhoeae
B. Neisseria lactamica
C. Neisseria sicca
D. Neisseria flavescens
A
A. Neisseria gonorrhoeae
42
Q
- Variation in colony types seen with fresh isolates
of Neisseria gonorrhoeae and sometimes with
Neisseria meningitidis are the result of:
A. Multiple nutritional requirements
B. Pili on the cell surface
C. Use of a transparent medium
D. All of these options
A
D. All of these options
43
Q
- Gram-negative diplococci recovered from an
MTM plate and giving a positive oxidase test
can be presumptively identified as:
A. Neisseria gonorrhoeae
B. Neisseria meningitidis
C. Neisseria lactamica
D. All of these options
A
D. All of these options
44
Q
- The Superoxol test is used as a rapid presumptive
test for:
A. Neisseria gonorrhoeae
B. Neisseria meningitidis
C. Neisseria lactamica
D. Moraxella (Branhamella) catarrhalis
A
A. Neisseria gonorrhoeae
45
Q
- Nonpathogenic Moraxella spp. capable of
growing on selective media for Neisseria can be
differentiated from Neisseria spp. by which test?
A. Catalase test
B. 10-unit penicillin disk
C. Oxidase test
D. Superoxol test
A
B. 10-unit penicillin disk
46
Q
- A Gram stain of a urethral discharge from a
man showing extracellular and intracellular
gram-negative diplococci within segmented
neutrophils is a presumptive identification for:
A. Neisseria gonorrhoeae
B. Neisseria meningitidis
C. Moraxella (Branhamella) catarrhalis
D. Neisseria lactamica
A
A. Neisseria gonorrhoeae
47
Q
- The β-galactosidase test aids in the identification
of which Neisseria species?
A. N. lactamica
B. N. meningitidis
C. N. gonorrhoeae
D. N. flavescens
A
A. N. lactamica
48
Q
- Cystine tryptic digest (CTA) media used for
identification of Neisseria spp. should be
inoculated and cultured in:
A. A CO2 incubator at 35°C for 24 hours
B. A CO2 incubator at 42°C for up to 72 hours
C. A nonCO2 incubator at 35°C for up to 72 hours
D. An anaerobic incubator at 35°C for up to
72 hours
A
C. A nonCO2 incubator at 35°C for up to 72 hours
49
Q
- Culture on MTM media of a vaginal swab
produced several colonies of gram-negative
diplococci that were catalase and oxidase positive
and Superoxol negative. Given the following
carbohydrate reactions, select the most likely
identification.
Glucose = +
Sucrose = Neg
Lactose = +
Maltose = +
Fructose = Neg
A. Neisseria gonorrhoeae
B. Neisseria sicca
C. Neisseria flavescens
D. Neisseria lactamica
A
D. Neisseria lactamica
50
Q
- Sputum from a patient with pneumonia produced
many colonies of gram-negative diplococci on a
chocolate plate that were also present in fewer
numbers on MTM after 48 hours. Given the
following results, what is the most likely
identification?
Catalase = +
Oxidase = +
DNase = +
Tributyrin hydrolysis = +
Glucose = Neg
Sucrose = Neg
Lactose = Neg
Maltose = Neg
Fructose = Neg
A. Moraxella catarrhalis
B. Neisseria flavescens
C. Neisseria sicca
D. Neisseria elongata
A
A. Moraxella catarrhalis
51
Q
- Resistance to which drug categorizes a strain
of Staphylococcus aureus as methicillin-resistant
Staphylococcus aureus (MRSA)?
A. Oxacillin
B. Colistin
C. Trimethoprim–sulfamethoxazole
D. Tetracycline
A
A. Oxacillin
52
Q
- An oxacillin-disk screen test is used to detect
Streptococcus pneumonia resistance to penicillin.
Using Mueller–Hinton agar with 5% sheep blood
and a 1 μg oxacillin disk, what is the recommended
inhibition zone size for penicillin susceptibility?
A. ≥5 mm
B. ≥10 mm
C. ≥15 mm
D. ≥20 mm
A
D. ≥20 mm
53
Q
- Which one of the following organisms is a known
producer of β-lactamase–producing strains, and
should be tested (screened) by a commercial
β-lactamase assay prior to susceptibility testing?
A. Streptococcus pneumoniae
B. Group B streptococci
C. Enterococcus spp.
D. Planococcus spp
A
C. Enterococcus spp.
54
Q
- Which test is used for the determination of
inducible clindamycin resistance in staphylococci
and streptococci?
A. E-test
B. D-zone test
C. A-test
D. Camp test
A
B. D-zone test
