COCCI Flashcards
(115 cards)
1
Q
GENERA AND SPECIES
A
S. Aureus
2
Q
COAGULASE-NEGATIVE
STAPHYLOCOCCI
A
S. Epidermidis
S. Haemolyticus
S. Saprophyticus
S. Lugdunensis
S. Schleiferi
3
Q
COAGULASE-NEGATIVE
STAPHYLOCOCCI
A
S. Capitis
S. Caprae
S. Warneri
S. Hominis
S. Auricularis
S. Cohnii
S. Xylosus
S. Simulans
Micrococcus spp. and related genera
Alloiococcus
4
Q
GENERAL CHARACTERISTICS: Staphylococcus
A
- catalase-producing gram (+) cocci
- aerobic or facultative anaerobic
- nonmotile, non spore forming
- spherical cells (0.5 to 1.5 micrometer)
- normal inhabitants pf skin, mucous membranes and intestines
5
Q
Catalase producing gram positive cocci belongs to what family?
A
Staphylococcaceae
6
Q
What are the species of staphylococcus that are not aerobic or facultative anaerobic?
A
- S. Aureus
- S. Sacchrolyticus
(Obligate anaerobes)
7
Q
Spherical cells appear what?
A
Singly, in pairs, and in clusters
8
Q
What are the colony characteristics of Staphylococcus aureus on blood agar plates (BAP)?
A
- Colonies are medium-sized (4 to 8 mm),
- cream-colored, white, or rarely light gold, with a “buttery” appearance
- Some colonies may be β-hemolytic
- Other Staphylococcus species may have gray colonies.
9
Q
Difference of staphylococci and micrococci based on the test Bacitracin (0.04 U)
A
Staphylo: Resistant
Micro: Susceptible (greater than or equal to 10 mm)
10
Q
Difference of staphylo and micrococci based on the test Furazolidone susceptibility test (100ug)
A
Staphylo: Susceptible (greater than or equal to 15 mm)
Micrococci: Resistant
11
Q
Difference of staphylo and micrococci based on the test Lysostaphin Sensitivity test
A
Staphylo: Susceptible (10 to 16 mm)
Micro: Resistant
12
Q
Difference of staphylo and microccoci based on the test Modified Oxidase Test or Microdase Test?
A
Staphylo: negative
Micro: positive
13
Q
Difference of staphylo and micrococci based on the test Growth on Furoxone-Tween 80-oil Red O Agar?
A
Staphylo: negative
Micro: positive
14
Q
difference of staphylo and micrococci based on the test Aid production from Glycerol (with erythromycin)
A
Staphylo: positive
Micro: negative
15
Q
Difference of staphylo and micrococci based on the test OF reaction
A
Staphylo: Fermenter
Micro: Oxidizer
16
Q
What are the test used between staphylococci and micrococci?
A
- Bacitracin (0.04 U)
- Furazolidone susceptibility test (100 ug)
- Lysostaphin sensitivity test
- Modified oxidase test / Microdase test
- Growth on Furoxone- Tween 80-oil Red O Agar
- Aid Production from glycerol (with erythromycin)
- OF reaction
17
Q
Staphylococci that is true coagulase positive and the most virulent species?
A
S. Aureus
18
Q
What media does S. Aureus grow?
A
- Nutrient agar (NA)
- Tryptic Soy Broth (TSB)
19
Q
On solid media, what are the distinct colony characteristics displayed by S. Aureus?
A
- round
- smooth
- opaque
- butyrous
20
Q
On Blood Agar Plate, what colony features does S. Aureus display?
A
Golden yellow color colonies and Beta hemolytic
21
Q
What is added to cultivate S. Aureus?
A
7.5 to 10% NaCl
22
Q
Is S. Aureus halophilic?
A
True
23
Q
S. Aureus is responsible to different spectrum of infections such as?
A
Skin, wound, and deep tissue infections
24
Q
What teichoice acid is found in the cell wall of S. Aureus?
A
Ribitol teichoic acid
25
________ and _______ protects the bacteria from lysis and aids in adherence
Peptidoglycan and teichoic acid
26
group of antigen unique to S. Aureus
Protein A
27
How does Protein A in S. Aureus prevents antibody mediated phagocytosis?
Protein A competes for the Fc portion of antibodies thereby preventing antibody-mediated phagocytosis by polymorphonuclear leukocytes
28
Protein A prevents what phagocytosis?
Antibody mediated phagocytosis
29
Protein A prevents phagocytosis by?
polymorphonuclear leukocytes
30
component on cell wall responsible for
clumping of the whole staphylococci in the
presence of plasma
Clumping factor
31
Clumping factor is responsible for the clumping in the presence of ____?
Plasma
32
This protects the S. Aureus from phagocytosis?
Capsular polysaccharide
33
What are the antigenic structure of S. Aureus?
- teichoic acid
- peptidoglycan
- protien A
- clumping factor
- capsular polysaccharide
34
Coagulates fibrinogen in the plasma and promotes fibrin layer formation around the staphylococcal abscess protecting the bacteria from phagocytosis
Coagulase (staphylocoagulase)
35
Staphylocoagulase promotes _____ around the staphylococcal abscess protecting the bacteria from _____
Fibrin layer formation ; phagocytosis
36
Types of coagulase
- cell-bound coagulase or clumping factor
- unbound or free coagulase
37
A coagulase that is bound to the cell wall and clots plasma of _____, _____, or _____?
Cell-bound coagulase or clumping factor ; human, rabbit, or pig plasma
38
Extracellular enzymes not bound to the cell wall and cause clot formation when bacterial cells are incubated with plasma
Unbound or free coagulase
39
Free coagulase cause clot when bacterial cells are _____?
Bacterial cells areIncubated with plasma
40
This hydrolyzes hyaluronic acid present in the intracellular ground substance, permitting the spread of infection
Hyaluronidase (spreading factor)
41
Permits the spread of infection
Hyaluronidase
42
Have fibrinolytic activities by dissolving fibrin clot
Staphylokinase (fibrinolysin)
43
Coagulase in staphylococcus is also know as?
Staphylocoagulase
44
Hyaluronidase is also known as
Spreading factor
45
Staphylokinase is also known as
Fibrinolysin
46
This is produced by both coagulas - and + staphylococci
Lipase (fat splitting enzyme)
47
This acts on lipids present on the surface of the skin (particularly fats and oil) that is secreted by the sebaceous glands
Lipase
48
____ is important in the formation of furuncles, carbuncles, and boils
Lipase
49
Lipase allows staphylococci to penetrate deeper into the skin tissues, promoting localized infections such as _______, ______, and________
Furuncles, carbuncles, and boils
50
What skin substance does lipase act on? And where they are produced?
Acts on fats and oils ; secreted by the sebaceous glands on the skin
51
Function of deoxyribonuclease and phosphatase in S. Aureus infections?
DNAse lowers the viscosity of exudates by breaking down DNA which enhances the pathogen’s mobility in infected tissues.
52
This destroys DNA
Deoxyribonuclease (DNAse) and phosphatase
53
What does Beta lactamase breaks down
Penicillin and beta lactam drugs
54
What are the enzymes of S. Aureus
- coagulase (staphylocoagulase)
- hyaluronidase (spreading factor)
- staphylokinase (fibrinolysin)
- lipase (fat splitting enzyme)
-DNAse and phosphatase
- protease
- gelatinase
- beta lactamase
55
What are the cytolytic toxins
Hemolysins and Leokocidins
56
This damage RBC, platelets and macrophages and cause sever tissue damage
Alpha hemolysin
57
Alpha hemolysins damage _____, _____, _____ and cause severe ______
Rbc, platelets, macrophage; severe tissue damage
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Predominant hemolysin
Alpha hemolysin
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Acts on the sphingomyelin in the plasma memrane of rbc
Beta hemolysin (Sphingomyelinase C)
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Where does beta hemolysin acts on?
Sphingomyelin in the plasma membrane of RBC
61
Enhance hemolytic activity on ________ and subsequent exposure to ________
Incubation at 37 celsius (heat labile) ; cold a 4 celsius
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Beta hemolysin is exhibited in what test?
CAMP test
63
effect of beta hemolysin
Lethal and dermonecrotic
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Beta hemolysin aka _____
Hot-cold lysine
65
Less toxic to cells than alpha or beta
δ-Hemolysin (delta hemolysin)
66
This toxin is produced by all S. Aureus strain
Delta hemolysin
67
Associated with Panton-Valentine Leukocidin (PVL)
Gamma hemolysin (y-hemolysin)
68
Gamma hemolysin is associated with
Panton-Valentine Leukocidin (PVL)
69
An exotoxin that is lethalto Polymorphonuclear leukocytes
Staphylococcal Leukocidin (Panton- Valentine Leukocidin)
70
PVL is lethal to?
Polymorphonuclear leukocytes
71
Mechanism of action of PVL?
Pore forming exotoxin that suppress phagocytosis, associated with severe cutaneous inections and necrotizing pneumonia
72
Pvl is associated what infections and dxs?
Severe cutaneous infections and necrotizing pneumonia
73
4 types of hemolysins?
Alpha, beta, delta and gamma hemolysins
74
What are staphylococcal enterotoxins?
They are heat stable exotoxins produced by S. Aureus that can withstand boiling and resistant to hydrolysis by gastric and jejunal enzymes
75
Enterotoxins can withstand boiling for ____
100 celsius for 30 minutes
76
Enterotoxins are resistant to hydrolysis by _____ and _____
Gastric and jejunal enzymes
77
How do enterotoxins affect the body?
They act as neurotoxins that stimulate vomiting through the vagus nerve
78
Percentage of S. Aureus isolates produce enterotoxins?
Enterotoxins are produced by 30% to 50% of S. Aureus isolates.
79
Which enterotoxins are primarily associated with food poisoning?
A, B, AND D
80
Enterotoxins that are implicated in TSS
B AND C ; SOMETIMES G AND I
81
What condition can enterotoxin B cause?
B
82
Toxic shock syndrome toxin-1 is also known as
Enterotoxin F or Pyrogenic exotoxin C
83
What condition is TST 1 particuarly associated with?
Menstruation-related toxic shock syndrome (TSS)
84
Menstruating-related TSS is especially linked to?
Tampon use
85
How is TSST1 produced by S. Aureus?
Chromosomal mediated toxin
86
TSS act as ____ and trigger an extreme immune response. leading to t cell proliferation and release cytokines
Superantigen
87
Effects of diff. Concentrationsof TSST1 on cells?
At low concentration = TSST1 causes leakage -> low blood pressure
At higher concentration = cytotoxic
88
TSST1 causes leakage by _____
Endothelial cells
89
Exfoliative toxins also known as
Epidermolytic toxin A and B or Exfoliatin serotypes A and B
90
what kind of protease is he exfoliative toxin?
serine protease
91
divides the intracellular bridges of the epidermis and causes excessive sloughing of the epidermis (stratum granulosum)
exfoliative toxin
92
what skin condition is caused by exfoliative toxins?
Staphylococcal Scalded Skin Syndrome
93
what skin condition is caused by exfoliative toxins?
Staphylococcal Scalded Skin Syndrome
94
SSSS is also known as
Ritter’s disease
95
Which skin condition s exfoliatie oxin implicaed in
Bullous Impetigo
95
result to a widespread blistering and peeling of the skin (appearance of burns)
Ritter's disease
96
Localized skin infection that also involves blister formation
Bullous impetigo
97
What are the toxins produced by S.aureus?
- Cytolytic toxins
- Enterotoxins
- TSST-1
- Exfoliative toxin
98
Mild inflammation of a hair follicle or oil gland; infected area is raised and red (INITIAL AND LESS SEVERE)
Folliculitis
99
Folliculitis is what?
Mild inflammation of hair follicle
100
Folliculatis forms ___ around hair follicles
domed pustules
101
Large, raised, superficial abscesses
Furuncles (boils)
102
Arises when a large abscess forms around the hair follicle
furuncles
103
Present with fever and chills, indicating systemic infection
Carbuncles
104
type of infection that affects the whole body and is caused by carbuncles
systemic
105
carbuncles consist of a ____ around several hair follicles
multilocular abscess
106
Larger pustules surrounded by a small zone of erythema
Bullous impetigo
107
Bullous impetigo is what?
Highly contagious infection that spread by direct contact, fomites or autoinoculation
108
Bullous impetigo spread through?
Direct contact, fomites, or autoinoculation
109
It is a superficial cutaneous infection commnly seen in newborns and young chidren
Impetigo
110
Impetigo is characterized by formation of ______ surrounded by red border
encrusted pustules
111
Clinical manifestation with multiple causes; symptoms are due to hypersensitivity reaction
Toxic epidermal necrolysis (TEN)
112
what are the cutaneous infections?
- folliculitis
- furuncles
- carbuncles
- bullous impetigo
- scalded skin syndrome
- toxic epidermal necrolysis
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