Unit 3 Staph/Strep Flashcards
1
Q
S. aureus: Clinical significance
A
- Surgical wound infections
- Skin infections and injuries
- Nosocomial
- TSS
2
Q
S. aureus: Colony morphology
A
-less whitecream; yellow more pronounced on CHOC
3
Q
S. aureus: Key tests
A
Coagulase positive
DNase positive
MSA positive (yellow)
4
Q
S. epidermitis: Clinical significance
A
- Most common CNS isolated from clinical specimens
- UTIs
- Surgical wound infections
5
Q
S. epidermitis: Colony morphology
A
-smooth, white, opaque, can be small
6
Q
S. saprophyticus:Clinical significance
A
Community acquired
- UTIs in young, healthy sexually active women and elderly men
- ANAEROBIC
7
Q
S. saprophyticus: Colony morphology
A
-BRIGHT white
8
Q
S. saprophyticus: Key tests
A
- Novobiocin resistant
- Variable MSA
9
Q
S. lugdunensis: key tests
A
- PYR positive
- Ornithine Decarboxylate +
10
Q
Micrococcus: Clinical significance
A
- oral and skin flora
- Typically nonpathogenic
11
Q
Micrococcus: Colony morphology
A
-lemon yellow
12
Q
Micrococcus: Gram stain
A
- loses a little of the crystal violet
- tetrads
13
Q
Micrococcus: Key tests
A
- Furazolidone Resistant
- Cannot ferment glucose
- Microdase Positive
- Bacitracin sensitive
14
Q
Rothia: Clinical significance
A
- oral flora
- opportunistic infection
15
Q
Rothia: Colony morphology
A
-gray/white, nonhemolytic and STICKY
16
Q
Rothia: Gram stain
A
-large gpc in pairs/clusters
17
Q
Rothia: Key tests
A
-variable catalase
18
Q
S. pyogenes: Clinical significance
A
- acute pharyngitis/strep throat
- TSS
- Necrotizing fasciitis
- Some people are “carriers”
- NEVER normal flora
- Sequelae: Rheumatic fever acute glomerulonephritis
19
Q
S. pyogenes: Colony morphology
A
- typically small, beta
- throat culture
20
Q
S. pyogenes: Key tests
A
- Bacitracin sensitive
- PYR positive
21
Q
S. agalactiae: Clinical significance
A
- Normal flora of GI tract
- GBS infection in young women, esp pregnant/post birth and neonates
- UTI
22
Q
S. agalactiae: Colony morphology
A
- typically larger grey soft beta
- can be nonhemolytic
23
Q
S. agalactiae: Key tests
A
- CAMP test positive
- PYR negative (looks like PYR pos Enterococcus)
- Sodium Hippurate hydrolysis positive
- Catalase (looks like Listeria)
24
Q
S. pneumoniae: Clinical significance
A
- Colonization/carriage common in children
- Community acquired pneumonia
- Bacterial meningitis
- Pili help attach to epithelial cells
25
S. pneumoniae: Colony morphology
-True alpha, dimpled or mucoid
26
S. pneumoniae: Gram stain
-GPC in pairs/chains, lancet chained
27
S. pneumoniae: Key tests
- Optochin sensitive
| - Bile solubility positive
28
Viridans Streptococci: 4 subgroups
S. mitis group
S.mutans group
S.bovis group --
S.anginosus group --
29
Viridans Streptococci: Clinical significance
- Normal flora of the oral cavity, oropharynx, GI tract & vagina
- Subacute Bacterial Endocarditis (SBE)
30
Viridans Streptococci: Colony morphology
-Usually alpha, can be gamma, can be dry-ish pinpoint
31
Nutritionally variant strep: 2 species
Abiotrophia & Granulicatella
32
Nutritionally variant strep: Clinical significance
- Normal oral flora
- CNS infections
- Ocular infections
- Growth requirements: thiol compounds and active form of vitamin B6
33
Nutritionally variant strep: Colony morphology and gram stain
-Does not grow on Blood agar
-spindly, loses crystal violet
bizarre
34
Nutritionally variant strep: Key tests
Staph streak pos
35
S.anginosus group: 3 species
Constellatus
Intermedius
Anginosus
36
S.anginosus group: Clinical significance
- can cause abscesses
| - Oral, brain and “shooters abscesses”
37
S.anginosus group: Colony morphology
- Alpha but can be beta
- Butterscotchy smell
- Grows better anaerobically
38
S.anginosus group: Gram stain
-Tiny GPCs in pairs/chains
39
S.anginosus group: Key tests
-grows better anaerobically
40
Enterococcus: Clinical significance
- Normal flora of GI tract and female GU tract
- HAI, UTI sepsis etc
- Acquired resistance to vancomycin concern for Infection Control
41
Enterococcus:Colony morphology
-Gray gamma or grey/white alpha
42
Enterococcus: Key tests
- PYR positive
- CATALASE negative weak/slow
- BE and NaCl positive
43
Enterococcus: 1st and 2nd most common
- E. faecalis most common
| - E. faecium 2nd most common
44
Enterococcus: Which two species can acquire vancomycin resistance?
- E. faecalis
| - E. faecium
45
Enterococcus: Which two species have intrinsic resistance to vancomycin?
-E. casseliflavus and E. gallinarum
46
S.bovis group: Clinical significance
-Sepsis associated with GI carcinoma
47
S.bovis group: Colony morphology
-gamma or weakly alpha
48
S.bovis group: Key tests
-BE + and NaCl -
49
Aerococcus: 2 species
U. urinae
| U. viridans
50
Aerococcus: Clinical significance
- Normal flora GU and URT
| - UTIs especially in elderly
51
Aerococcus: Colony morphology
-alpha hemolytic tiny
52
Aerococcus: Gram stain
-GPC in CLUSTERS
53
Aerococcus: Key test
- BE- and NaCl +
| - PYR/LAP, one is positive other is negative
54
Pediococcus: Clinical significance
Opportunistic pathogen; bacteremia/abdominal infection
55
Pediococcus: Colony morphology
-small grey alpha
56
Pediococcus: Key tests
No ways to definitively determine
57
Leuconostoc: Clinical significance
Opportunistic pathogen
58
Leuconostoc: Colony morphology
-small grey alphish or gamma
59
Leuconostoc: Gram stain
-ovoid cocci, often in chains
60
Leuconostoc: Key tests
No ways to definitively determine
61
Gemella: Colony morphology
- grows better anaerobically
- slow grower on blood
- tiny/small grey
62
Gemella: Gram stain
-GPC in clusters, tetrads and chains
63
Gemella: Key tests
Difficult to ID biochemically
64
Which staph and friends species has a variable/weak catalase result?
Rothia
65
Which staph and friends species is coag positive?
S. aureus
66
Which staph and friends species can have variable coag results?
S. saprophyticus
67
Which staph and friends species is resistant to novobiocin?
S. saprophyticus
68
Which staph and friends species is microdase positive?
Micrococcus
69
Which staph and friends species is negative for glucose fermentation?
Micrococcus
70
Which staph and friends species is susceptible to Bacitracin?
Micrococcus
71
Which staph and friends species is resistant to Furalozidone?
Micrococcus
72
Which staph and friends species is DNase positive?
S. aureus
73
Which staph and friends species grows on mannitol salt agar?
S. aureus
| S. saprophyticus is variable
74
Which staph and friends species is PYR positive?
S. lugdunensis
75
What does the latex agglutination coagulation test detect?
Protein A in cell wall and clumping factor
76
Which staph and friends species are generally normal flora?
Micrococcus (oral and skin) and Rothia (oral)
77
Which strep and friends species is actually in clusters on a gram stain?
Aerococcus
78
Which strep and friends species is catalase negative but has a slow/weak reaction?
Enterococcus
79
Which strep and friends species is susceptible to Bacitracin?
Group A Strep/ S. pyogenes
80
Which strep and friends species is susceptible to Optochin?
S. pneumoniae
81
Which strep and friends species is bile soluble?
S. pnuemoniae
82
Which strep and friends species are PYR positive?
Group A Strep/ S. pyogenes and Enterococcus
Nutritionally Variant Strep
83
Which strep and friends species is positive for both Bile Esculin and 6.5% NaCl?
Enterococcus
84
Which strep and friends species is negative for both Bile Esculin and 6.5% NaCl?
Viridans Group
85
Which strep and friends species is negative for Bile Esculin and positive for 6.5% NaCl?
Aerococcus and group B
86
Which strep and friends species is positive for Bile Esculin and negative for 6.5% NaCl?
S. bovis/S. gallolyticus
87
Which strep and friends species is CAMP test positive?
Group B strep/ S. agalactiae
88
Which strep and friends species is confirmed with a positive Staph streak?
Nutritionally variant Strep
89
Which staph and friends species is a known biofilm former?
S. epidermidis
90
Which staph and friends species is the most common CNS isolated from clinical specimens?
S. epidermidis
91
Which staph and friends species causes UTIs in young, healthy, sexually active women?
S. saprophyticus
92
In what type of specimen would you need to rule out S. saprophyticus?
Urine
93
Which staph and friends species prefers anaerobic conditions?
S. saprophyticus
94
Which staph and friends species can make clumping and cause confusion on a coagulase test?
S. saprophyticus
95
MSA agar: positive vs negative?
P: yellow
N: pink
96
What is chromagar used for? Organism and source
MRSA
Nasal swabs
97
Which staph and friends species can get stringy and cause confusion on a coagulase test?
Rothia
98
Which strep and friends species is normal flora of the GI tract?
Group B/ S. agalactiae
99
In which strep and friends species is asymptomatic carriage normal in children?
S. pneumoniae
100
Which strep and friends species is normal flora of the oral cavity, oropharynx, GI tract and vagina?
Viridans Strep
101
Which strep and friends species is normal flora of the GI tract and female GU tract?
Enterococcus
102
Which strep and friends species is normal flora of the GU and URT?
Aerococcus
103
Which strep and friends species is normal flora of the oral flora only?
Nutritionally variant strep
104
What two tests and results confirm group A strep?
PYR positive
| A disc susceptible
105
What is a useful test to rule out Group B strep?
PYR negative due to the fact that it looks like Enterococcus
106
Which strep and friends species is confused with Listeria and how to differentiate?
Nearly identical colony morphology: Group B
Listeria is catalase positive
GPB
Reverse CAMP pos
Hippurate pos
107
Which strep and friends species is lancet shaped?
S. pneumoniae
108
What test is useful for speciating Aerococcus?
LAP
109
Which strep and friends species grow better anaerobically?
S. anginosus and Gemella
110
When would you suspect NVS?
Does not grow on Blood, but does grow on chocolate
| Bizarre gram stain
111
Which strep and friends species are vancomycin resistant other than the VRE?
Pediococcus and Leuconostoc
112
What type of specimen require us to rule out Group A strep?
Throat swab/respiratory
113
When would a gram stain not be needed for S. pneumoniae?
Respiratory alphas
