Week 4 Flashcards
1
Q
Contain a high content of peptidoglycan and low level of lipid in the cell wall
A
Gram Positive Cocci
2
Q
Gram Positive infections are?
A
pyogenic
3
Q
Peptidoglycan in Gram Negative?
A
Single layered
4
Q
Three Generas of Family Micrococcaceae
A
Planococcus, Stomatococcus, Micrococcus
5
Q
State the Gram and Catalase of the Family Staphylococcaceae
A
Gram: Positive
Catalase: Positive
6
Q
State the Gram and Catalase of the Family Micrococcaceae
A
Gram: Positive
Catalase: Positive
7
Q
The gram and catalase of the Family: Streptococcaceae
A
Gram: Positive
Catalase: Negative
8
Q
The genera of the Family: Streptococcaceae
A
Streptococcus
9
Q
Gram Positive cocci in Staphylococci are arranged in what form?
A
Tetrads or Clusters
10
Q
Gram Positive cocci in Staphylococci are arranged in what form?
A
Tetrads or Clusters
11
Q
What type of anaerobes have in Staphylococci?
A
Facultative anaerobes
12
Q
What type of anaerobes have in Staphylococci?
A
Facultative anaerobes
13
Q
What type of anaerobes have in Staphylococci?
A
Facultative anaerobes
14
Q
What type of Gram Positive Bacteria has this characteristics?
- Oxidase Negative
- Non-motile, nonsporeforming glucose fermenters
- Grows in 7.5-10% NaCl
A
Staphylococci
15
Q
What type of Gram Positive Bacteria has this characteristics?
- Oxidase Negative
- Non-motile, nonsporeforming glucose fermenters
- Grows in 7.5-10% NaCl
A
Staphylococci
16
Q
What are the Catalase Postive in Gram Positive Cocci?
A
Staphylococcus and Micrococcus
17
Q
What is the Catalase Negative in Gram Positive Cocci?
A
Streptococcus
18
Q
What is the Catalase Negative in Gram Positive Cocci?
A
Streptococcus
19
Q
Test the ability of the organism to breakdown of H2O2 (3%) into oxygen and water
A
Catalase Test
20
Q
How to determine if it is Catalase Positive?
A
Has copious bubble formation
21
Q
How to know if its catalase negative?
A
No or few bubbles
22
Q
How to know if its catalase negative?
A
No or few bubbles
23
Q
Test for the position of Cytochrome to produce a dark-blue end product when reacted.
A
Microdase Test (Modified Oxidase Test)
24
Q
Test for the position of Cytochrome to produce a dark-blue end product when reacted.
A
Microdase Test (Modified Oxidase Test)
25
What color it shows if its Microdase Positive?
Blue to purple-blue color
26
What color it shows if its Microdase Positive?
Blue to purple-blue color
27
What color it shows if its Microdase Negatve?
No color change
28
Catalase Positive and Microdase Positive
Micrococcus spp.
29
Microdase Negative
Staphylococcus spp.
30
-Most clinically significant specie of Staphylococci
-Present in various skin surface and nares
-It causes infection when it enters a normally sterile site
-Cause of nosocomial or hospital-acquired infections
-It is also one of the common causes of food poisoning
-It can be cultivated by adding 7.5% to 10% NaCl
Staphylococcus Aureus
31
Staphylococcus Aureus: What type of Virulence Factor
-Heat stable exotoxins: A-E and G-J
-A,B, and D are associated to food poisoning; reheating contaminated food will not prevent disease
-Enterotoxin B (super antigen) was linked to psuedomembranous enterocolitis
ENTEROTOXINS
32
Staphylococcus Aureus: What type of Virulence Factor
-Formerly known as Enterotoxin F(superantigen-activate aggresive immune response)
-Causes menstruating-associated TSS (Tampon use) absorbed through vaginal mucosa
Toxic Shock Syndrome Toxin (TSST-1)
33
Staphylococcus Aureus: What type of Virulence Factor
-Also known as Exfoliatin serotypes A and B
-Causes SSS (Scalded Skin Syndrome or Ritter disease) and bullous impetigo (large pustules with erythema)
Epidermolytic toxins A and B
34
Staphylococcus Aureus: What type of Virulence Factor
-Panton-Valentine Leukocidin
-Hemolysins
Cytolytic Toxins
35
Staphylococcus Aureus: What type of Virulence Factor
-Coagulase
-Fibrinolysin
-Deoxyribonuclease (DNAse)
-Hyaluronidase
-Lipase
Enzymes
36
Staphylococcus Aureus: What type of Virulence Factor
-Binds to the Fc portion of IgG, neutralizes it and block phagocytosis
Protein A
37
Staphylococcus Aureus: What type of Virulence Factor
-Breakdown of beta-lactam ring in penicillin molecule
Beta lactamase
38
another name for beta lactamase
Penicillinase
39
Staphylococcus Aureus: What type of Infections or Associated Disease
-mild inflammation of hair follicle or sebaceous gland
Folliculitis
40
Staphylococcus Aureus: What type of Infections or Associated Disease
-large, raised superficial abscess
Furuncles
41
Staphylococcus Aureus: What type of Infections or Associated Disease
-invasive lesions develop from multiple furuncles, may progress into deeper tissues
Carbuncles
42
Staphylococcus Aureus: What type of Infections or Associated Disease
-pustules are larger and surrounded by a small zone of erythema
Bullous Impetigo
43
Staphylococcus Aureus: What type of Infections or Associated Disease
-extensive exfoliative (profuse peeling) dermatitis caused by staphylococcal exfoliative or epidermolytic toxin
Scalded Skin Syndrome (Ritter Disease)
44
Staphylococcus Aureus: What type of Infections or Associated Disease
-fatal disease characterized by sudden onset of fever, chills, vomiting, diarrhea, muscle aches, and rash, w/c could lead to hypotension and shock.
Toxic Shock Syndrome
45
Staphylococcus Aureus: What type of Infections or Associated Disease
-clinical manifestation w/multiple causes; it is most commonly drug induced, but some cases may have been linked to infections and vaccines.
Toxic Epidermal Necrolysis (TEN)
46
Virulence Factor: Exopolysaccharide "slime" or biofilm
:Enhances organisms adhesion to implanted medical devices and provides refractoriness to host defense
Infections and Associated Disease
:Hospital acquired UTI and prosthetic valve endocarditis
Staphylococcus epidermidis
47
Virulence Factor: Adheres to the epithelial cells lining the urogenital tract
Infections and Associated Disease: Causes UTI in sexually activee, young females and in older women with indwelling catheters
Staphylococcus saprophyticus
48
Virulence Factor: Gene mecA- encodes for oxacillin resistance
Infections and Associated Disease: Community associated and hospital acquired infections (endocartitis and UTI)
Staphylococcus lugdunensis
49
Virulence Factor: Vancomycin Resistance
Infections and Associated Disease: Community associated and hospital acquired infections (endocarditis and UTI)
Staphylococcus haemolyticus
50
What specimen are preffered in Isolation and Identification
Aspirate or Swabs
51
Enriched isolation of Staphylococci
Blood Agar
52
Selective medium for Gram positive cocci
Colistin-nalidixic acid or Phenylethyl Alcohol Agar
53
Selective and differential for Staphylococcus
Mannitol Salt Agar
54
CNA AND PEA inhibit a Gram _______ Bacteria
Negative
55
CNA/PEA: has growth (what type of cocci)
Staphylococcus abd Streptococcus
56
CNA/PEA: No growth: Total Inhibition
E. Coli
57
CNA/PEA: No growth: Partial Inhibition
P. mirabilis
58
Cultural Characteristics: Medium to large; round, smooth, entire, translucent, creamy; mostly pigmented yellow and is B- hemolytic
S. Aureus
59
Cultural Characteristics: Small to medium; translucent, gray-white colonies, non hemolytic
S. epidermidis
60
Large; smooth, opaque, convex; usually white, yellow or orange
S. saprophyticus
61
Identification Methods
Catalase: positive
Microdase:negative
Aerobic Growth: positive
Anaerobic Growth: positive
Bacitracin: resistant
Furazolidone:susceptible
Lysostaphin:susceptible
Staphylococcus
62
Identification Methods
Catalase: positive
Microdase: positive
Aerobic Growth: positive
Anaerobic Growth: negative
Bacitracin:susceptible
Furazolidone: resistant
Lysostaphin: resistant
Micrococcus
63
Coagulase Positive
Staphylococcus Aureus
64
Coagulase Negative: Novobiocin Susceptible
Staphylococcus Epidermidis
65
Coagulase Negative: Novobiocin Resitant
Staphylococcus Saprophyticus
66
Identification Methods
Coagulase: Positive
DNAse: Positive
MSA Fermentation: Positive
Novobiocin:
S. Aureus
67
Identification Methods
Coagulase: Negative
DNAse:Negative
MSA Fermentation: Negative
Novobiocin: Susceptible
S. epidermidis
68
Identification Methods
Coagulase: Negative
DNAse: Negative
MSA Fermentation: Positive/Negative
Novobiocin: Resistant
S. saprophyticus
69
How to know if its Bacitracin Susceptible? and give an example
Zone Diameter greater than 10mm, Micrococcus
70
How to know if its Bacitracin Resistant? and give an example
No zone of Inhibition, Staphylococcus
71
Test for the ability of bacteria to convert fibrinogen into fibrin
Coagulase Test
72
2 types of Coagulase Test
Bound coagulase and Free coagulase
73
Detects bound coagulase "clumping factor"
Coagulase Slide Test
74
Detects Free coagulase
Coagulase Tube Test
75
Coagulase Slide Test: Positive
S. Aureus, S. lugdunensis, S. schleiferi
76
Coagulase Slide Test: Negative
S. epidermidis and others
77
Coagulase Tube Test: Positive
S. Aureus
78
Coagulase Tube Test: Negative
S. epidermidis and others
79
Test the ability of the organism to hydrolyze DNA
DNase test
80
How do we know if its DNase test positive?
CLEAR ZONE (Hydrolysis of the surrounding medium)
81
Example of DNase test positive?
S. Aureus
82
How do we know if its DNase test negative?
No clearing observed
83
Example of DNase test negative?
S. epidermidis and S. saprophyticus
84
-Selective and differential medium
-test for the ability to ferment mannitol
-contains NaCl (7.5%), D-mannitol, phenol red
Mannitol Fermentation Test
85
Color: Growth with Fermentation
Yellow halos surrounding growth
86
Color: Growth without fermentation
Plate remains pink to red
87
How to know if its novobiocin susceptible?
Zone diameter greater than 16 mm
88
How to know if its Novobiocin Resistant?
Zone Diameter less than or equal to 16 mm
89
Example of Novobiocin Susceptible
S. epidermidis
90
Example of Novobiocin Resistant
S. saprophyticus
91
Test for the ability of the organism to hydrolyze the substrate L-pyrrolidonyl-B-naphthylamide; Final Rgt: p-dimethylaminocinnamaldehyde
Pyrrolidonyl Arylamidase (PYR) Test
92
How to know if its PYR Test Positive
Bright color within 5 minutes (pink to cherry-red color after addition of color developer)
93
Example of PYR Test Positive
S. lugdunensis and S. intermedius
94
How to know if its PYR Negative
No color change or an orange color
95
How to know if its PYR Negative
No color change or an orange color
96
Example of PYR Test Negative
S. Aureus
97
-Used for discrepant macrolide test
-Used to test inducible resistance on S. aureus strains demonstrating an initial antibiotic susceptibility profile
D-Zone Test (Double-disk diffusion Test)
98
Result of D-zone Test
Erythromycin resistant, clindamycin sensitive
99
Another name for D-Zone Test?
Double-disk diffusion test
