Module 4.1 Staphylococcaceae and Micrococcus Flashcards
(187 cards)
1
Q
Staphylococcus belongs to family:
A
Staphylococcaceae
2
Q
How many species does Staphylococcus bacteria have?
A
45 species
3
Q
How many subspecies does Staphylococcus abcteria have?
A
21
4
Q
Three Staphylococcus bacteria most commonly seen in human infections
A
- S. aureus
- S epidermidis
- S. saprophyticus
5
Q
gram staining of Staphylococcus
A
gram positive
6
Q
diameter of Staphylococcus
A
0.5 - 1.5 um
7
Q
motility of Staphylococcus
A
non-motile
8
Q
T or F: Staphylococcus is a spore forming bacteria
A
false
It is non-spore forming
9
Q
oxygen requirement of Staphylococcus
A
facultative anaerobe
10
Q
Staphylococcus:
catalase positive or negative?
A
catalase-positive
11
Q
temperature requirement of Staphylococcus
A
37 degrees C
12
Q
osmotic pressure of Staphylococcus
A
halotolerant
13
Q
T or F: Staphylococcus is fermentative
A
True
Staphylococcus is fermentative.
14
Q
Staphylococcus:
nitrate reduction, +/- ?
A
+
15
Q
Three additional characteristics of Staphylococcus
A
Coagulase (+)
DNase (+)
Mannitol fermenter
16
Q
T or F: Staphylococcus is not a part of normal human microflora.
A
False
Staphylococcus is a part of normal human flora.
17
Q
Staphylococcus is most commonly present in what part of the human body
A
anterior nares (nostrils)
18
Q
what percentage of adults have Staphylococcus in the anterior nares
A
20-40%
19
Q
Staphylococcus is carried by normal individuals _____ rather than chronically
A
intermittently
20
Q
4 other sites in the human body that Staphylococcus colonize
A
- nasopharynx
- perineum
- axillae (armpit)
- vagina
21
Q
most common mode of Staphylococcus transmission
A
contaminated hands
22
Q
Though Staphylococcus is part of the normal human flora, it is able to cause _________ under appropriate conditions
A
opportunistic infections
23
Q
Though Staphylococcus is part of the normal human flora, it is able to cause _________ under appropriate conditions
A
opportunistic infections
24
Q
6 factors that predispose an individual to serious S. aureus infections.
A
- breaks in continuity of mucosal and cutaneous surface
- foreign bodies or implants
- prior infection (viral influenza)
- defect in immunity
- chronic diseases
- antimicrobial administration
25
3 kinds of diseases caused by Staphylococcus aureus
1. cutaneous diseases
2. toxigenic diseases
3. systemic diseases
26
5 cutaneous staphylococcal diseases
1. Folliculitis
2. Hidradenitis suppurativa
3. Furuncle
4. Carbuncle
5. Impetigo
27
Staphylococcal infections are pus-forming or _____
pyogenic
28
All Staphylococcal infections are _____
abscesses
29
Staphylococcal infections of the skin occur through: (3)
1. wounds
2. follicles
3. skin glands
30
What is an abscess?
inflamed, fibrous lesion enclosing a core of pus
31
mild inflammation of the superficial dermis that is restricted to the hair follicles
Folliculitis
32
term for opening of the hair follicles
ostia
33
folliculitis is characterized by:
1. small, reddish, painful lesions
| 2. absence of systemic symptoms
34
If folliculitis occurs in the eyelid, it is referred to as ___
stye
35
If folliculitis occurs in the eyelid, it is referred to as ___
stye
36
It is a chronic/relapsing inflammation. It is not a primarily a staphylococcal disease, but is complicated by S. aureus
Hidradenitis suppurativa
37
Hidradenitis suppurativa usually involves areas that bear:
apocrine glands
38
4 sites where Hidradenitis suppurativa most commonly appear
axillae
groin
perineal and perianal regions
39
Hidradenitis suppurativa is associated with blocked and infected____
apocrine sweat glands
40
Hidradenitis suppurativa is associated with blocked and infected____
apocrine sweat glands
41
Hidradenitis suppurativa is associated with presence of multiple lesions caused by blocked and infected____
apocrine sweat glands
42
Hidradenitis suppurativa is characterized by the presence of __, __, __, and absence of __
local pain
swelling
erythema
systemic symptoms
43
It is a deeper seated infection of the hair follicles
furuncle
44
furuncle is latin for:
little thief
45
another term for furuncle
boils
46
In furuncles, the inflammation of single hair follicle/ sebaceous gland progresses into a ______
large, red, extremely tender abscess or pustule
47
term for when furuncles appears in clusters
furunculosis
48
4 common sites for furuncles
buttocks
breasts
axillae
back of the neck
49
larger and deeper lesion which is created by aggregation & interconnection of furunculosis
carbuncle
50
characteristics of carbuncle
- extremely painful
| - can be fatal in elderly when it gives rise to systemic disease
51
carbuncle is latin for
little coal
52
where are carbuncles mostly found
tough skin (back of the neck)
53
cutaneous disease that is not confined to follicles and skin glands
impetigo
54
impetigo is latin for:
to attack
55
characteristics of impetigo
- bubble like epidermal sweeping
| - can break and peel away like localized scalding skin syndrome
56
impetigo is usually present in exposed areas like:
face
57
impetigo may spread to other areas through:
autoinoculation
58
two types of impetigo
1. non-bullous
| 2. bullous
59
impetigo that begins as single red macule (patch) or papule, which quickly becomes a vesicle that ruptures & forms an erosion
non-bullous
60
most common type of impetigo (70%)
non- bullous
61
impetigo that is a localized form of scalded skin syndrome and commonly affects neonates
bullous
62
impetigo where the lesion dries to form a honey-colored crusts w/ erythematous (reddish) margins
non-bullous
63
impetigo which has oozing yellow crust but has no surrounding erythema
bullous
64
impetigo that is usually found in moist intertriginous areas (diaper area, axillae, neck folds)
bullous
65
impetigo that may be pruritic (itchy)
non-bullous
66
3 types of staphylococcal toxigenic diseases
1. staphylococcal food poisoning
2. staphylococcal scalded skin syndrome
3. staphylococcal toxic shock syndrome
67
gastrointestinal illness that is caused by eating food contaminated w/ S. aureus toxin
Staphylococcal food poisoning
68
Staphylococcal food poisoning acute symptoms appear within _____ of ingestion
2-6 hours
69
Staphylococcal food poisoning recovery occurs within ___
24 hours
70
two symptoms of Staphylococcal food poisoning
- emesis (vomiting often projectile)
| - diarrhea (less frequent)
71
disease associated w/ handling or unrefrigerated custards, sauces, cream pastries, processed meats, chicken salad, ham
Staphylococcal food poisoning
72
T or F: Staphylococcal food poisoning cannot happen with salt preserved food.
False
| Staphylococcus is halotolerant.
73
T or F: Staphylococcus toxins do not alter food taste or smell.
True
74
T or F: Staphylococcal food poisoning is a food-borne infection
False
| food intoxication
75
causes widespread erythema and separation of the dermis from the epidermis which results into exposure of large areas of denuded and raw skin
Staphylococcal Scalded Skin Syndrome
76
another term form Staphylococcal Scalded Skin Syndrome
Ritter's disease
77
Staphylococcal Scalded Skin Syndrome is usually seen in
neonates (less than a month old) children less than 5 years
78
appears as bullous lesions over large areas of the body
Staphylococcal Scalded Skin Syndrome
79
Staphylococcal Scalded Skin Syndrome symptoms wane over ____
5-7 days
80
resembles sunburns followed by skin desquamation and involvement of multiple organ systems
Staphylococcal toxic shock syndrome (TSS)
81
symptoms of Staphylococcal toxic shock syndrome (TSS)
initially flu-like
fever
hypotension
skin rash
82
desquamation occurs in Staphylococcal toxic shock syndrome after __
1-2 weeks
83
some symptoms associated with Staphylococcal toxic shock syndrome
```
vomiting
diarrhea
renal failure
headache, chills
sore throat
conjunctivitis
```
84
diseases associated w/ use of high-absorbency tampons
Staphylococcal toxic shock syndrome
85
most common pattern of staphylococcal infections
focal
| local cutaneous to other sites
86
three kinds of miscellaneous systemic infections caused by staphylococcus
1. osteomyelitis
2. pneumonia
3. bacteremia
87
Bone infection caused by staphylococcus
Osteomyelitis
88
staphylococcus infection that usually occurs after influenza viral infections
pneumonia
89
three consequences of bacteremia
Endocarditis
Arthritis
Meningitis
90
promotes colonization of, spread in, or damage to host tissues, enhance survival within cells
Virulence factors
91
consists of polysaccharides which mediates attachment to host cells or tissues
microcapsule
92
inhibits phagocytosis by polymorphonuclear leukocytes unless specific antibodies are present
microcapsule
93
can only be visualized through electron microscope
microcapsule
94
microcapsule has how many serotypes
11
95
microcapsule serotype which is responsible for majority of infections
type 5 and type 8
96
tagging of foreign pathogens using opsonin for elimination by phagocytes, without which negatively charged pathogen and phagocyte would repel each other
opsonization
97
bacterial surface protein found in some S. aureus strains which prevents opsonization
protein A
98
mechanism of protein A
a. protein A binds to Fc portion of IgG
b. IgG is no longer capable of binding to Fc receptor on phagocyte
c. no opsonization
99
blocks complement fixation
protein A
100
inactivates toxic hydrogen peroxide and free radicals
catalase
101
primary killing mechanism of phagolysosome
myeloperoxidase system
102
forms toxic hydrogen peroxide & free radicals
myeloperoxidase system
103
coats the bacterial cells, hiding their antigenic surface, thus protecting them from phagocytosis and immune response.
fibrin
104
promotes conversion of fibrinogen to fibrin causing plasma to clot
coagulase
105
hydrolyzes DNA, facilitating the spread of bacteria by liquefying abscess materials.
DNase
106
known as the “spreading factor
hyaluronidase
107
hydrolyzes the intercellular
| matrix of acid mucopolysaccharides in tissue, spreading the organism to adjacent areas
Hyaluronidase
108
hydrolyzes lipids
lipase
109
helps spread the organism in cutaneous and
| subcutaneous tissues.
lipase
110
plasminogen activator
Staphylokinase
111
dissolves fibrin clot (fibrinolysis) which might aid in the spread of infection to contiguous tissues
Staphylokinase
112
makes tissues more susceptible to damage and destruction through complement activation
Phosphatidylinositol-specific phospholipase C
113
under plasmid-control and transmitted through transduction and conjugation
β-lactamase
114
provides resistance to β-lactam antibiotics such as penicillin, penicillin derivatives (penams), and cephalosporins.
β-lactamase
115
four-atom ring that is common to the molecular structure of some antibiotics
β-lactam
116
the β-lactamase breaks the β-lactam ring open through:
hydrolysis
117
lyse red blood cells by disrupting their cell membranes
hemolysins
118
damage cell membranes of neutrophils and macrophages, causing them to lyse.
Leukocidins
119
Hemolysins and Leukocidins are together referred to as:
Blood Cell Toxins
120
toxins that help incapacitate the host’s phagocytic line of defense
Blood Cell Toxins
121
5 blood cell toxins
```
⍺ (alpha)-Hemolysin
β (beta)-Hemolysin
δ (delta)-Hemolysin
γ (gamma)-Hemolysin
Panton-Valentine Leukocidin (PVL)
```
122
heterogeneous protein which forms pores on target cell membrane so monovalent cations pass leading to osmotic swelling and cell rupture
⍺ (alpha)-Hemolysin
123
potent toxin which lyses RBCs
| and damages monocytes, macrophages, lymphocytes, skeletal muscle, heart, and renal tissue
⍺ (alpha)-Hemolysin
124
active against thrombocytes (platelets)
⍺ (alpha)-Hemolysin
125
contribute to septic thrombotic
| events during S. aureus bacteremia.
⍺ (alpha)-Hemolysin
126
protein exotoxin that acts as sphingomyelinase degrading
| sphingomyelin in the cell membrane
β (beta)-Hemolysin
127
toxic for many kinds of cells
β (beta)-Hemolysin
128
β (beta)-Hemolysin is also referred to as
“hot-cold”
129
its hemolytic properties are enhanced by subsequent exposure of RBCs to low temperatures.
β (beta)-Hemolysin
130
encodes β (beta)-Hemolysin
lysogenic bacteriophage
131
β-hemolysin is cytotoxic not only to human erythrocytes but as well as to:
monocytes
132
Cell death from β-hemolysin result from disruption of host cell's __
plasma membrane fluidity
133
β-hemolysin is said to
| be inactive against : 3
granulocytes
lymphocytes
fibroblasts.
134
small peptide that acts primarily as a surfactant or a detergent-like molecule
δ (delta)-Hemolysin
135
interacts with cell membranes and forms channels resulting in slow leakage of cellular contents.
δ (delta)-Hemolysin
136
It may have a role in S. aureus diarrheal diseases.
δ (delta)-Hemolysin
137
leukocidin that lyses WBCs and composed of two proteins
γ (gamma)-Hemolysin
138
two proteins of γ (gamma)-Hemolysin
S and F
139
Affected cells undergo degranulation of the cytoplasm, cell swelling, and lysis.
γ (gamma)-Hemolysin
140
leads to massive release of inflammatory mediators which are responsible for necrosis and severe inflammation.
γ (gamma)-Hemolysin
141
cells affected by γ (gamma)-Hemolysin undergoes
degranulation of the cytoplasm
cell swelling
lysis
142
produced by lysogenized strains
| of S. aureus
Panton-Valentine Leukocidin (PVL)
143
active against neutrophils and
| causes tissue necrosis
Panton-Valentine Leukocidin (PVL)
144
also consists of S and F proteins that act on WBC
Panton-Valentine Leukocidin (PVL)
145
Three pore-forming blood cell toxins
⍺ (alpha)-Hemolysin
γ (gamma)-Hemolysin
Panton-Valentine Leukocidin (PVL)
146
superantigen found in about 20%
| of S. aureus isolates.
Toxic Shock Syndrome Toxin (TSST-1)
147
epidermolytic toxins that cause the intraepithelial splitting of cellular linkages seen in SSSS
Exfoliative toxins (or exfoliatins)
148
the dissolution of this part of the skin results in the manifestation of SSSS
mucopolysaccharide matrix of the stratum granulosum in the epidermis
149
two distinct proteins of the same
| molecular weight
Exfoliative toxin A (ET-A)
| Exfoliative toxin B (ET-B)
150
Exfoliative toxins that is plasmid-mediated.
ET-B
151
Exfoliative toxins produced by lysogenized strains of S. aureus;
ET-A
152
heat-stable exotoxins which are responsible for the clinical features of staphylococcal food poisoning.
Enterotoxins A-E, G-J, K-R, U, V
153
heat requirement to inactivate staphylococcal enterotoxins
100oC for at least 30 minutes
154
Clothes and bedding that may cause reinfection should be dry-cleaned at what temperature
70°C or higher
155
used in showering for adults to increase the bactericidal activity of the skin
chlorhexidine or hexachlorophene
156
used for persons found to be a source of an outbreak
nasal creams(mupirocin, neomycin, and bacitracin)
oral therapy (rifampin, ciprofloxacin)
157
effective in surgical procedures such as hip and cardiac valve
replacements
Chemoprophylaxis
158
given during and shortly
| after surgery to reduce intraoperative infection and minimize superinfection
Methicillin
a cephalosporin
vancomycin
159
The most commonly encountered staphylococcal species
Staphylococcus epidermidis
160
S. epidermidis characteristics different to S. aureus
Coagulase(-)
DNase(-)
Non-mannitol fermenter
161
Comprises 99% of the normal flora of the skin
Staphylococcus epidermidis
162
Considered opportunistic pathogens, but are substantially less virulent than S. aureus
Staphylococcus epidermidis
163
Staphylococcus epidermidis is associated mainly with
nosocomial infections due to contaminated medical devices
164
associated with prosthetic heart valves; also pacemaker wires, implanted defibrillators, and vascular grafts
Endocarditis
165
associated with prosthetic joint, or hip implant
Arthritis
166
associated with indwelling urinary catheters
Urinary tract infection (UTI)
167
associated with IV catheters
Bacteremia
168
pathogenesis of Staphylococcus epidermidis
adherent slime forming biofilm on prosthetic devices
169
characteristics of S. saprophyticus that are dofferent from S. aureus
- Coagulase(-)
- DNase(-)
- Urease (+)
- Mannitol fermentation (variable)
170
primary site of S. saphrophyticus colonization in humans
gastrointestinal tract (primarily the rectum)
171
S. saprophyticus is alao part of the normal flora of :
```
genitourinarinay tract (urethra cervix)
perineum
```
172
most common cause of community acquired UTI in young sexually active females
E. coli
173
second most common cause of community acquired UTI in young sexually active females
S. saprophyticus
174
pathogenesis of S. saprophyticus
production of adherent slime and urease
175
an enzyme that hydrolyzes urea in urine resulting in the formation of ammonia and ammonium carbonate, making the urine alkaline and favoring bacterial growth
urease
176
often resemble and ,therefore, are easily confused with staphylococci.
Micrococcus
177
habitat of micrococcus
free-living environments such as air, soil, various extreme environments and food
178
extreme environments that serve as habitats for Micrococcus
marine sediment
deep sea mud
activated sludge
179
most common foods where S. saprophyticus is present
fermented seafood
180
Micrococcus is considered a normal microbiota of the human ___
skin
mucosa
oropharynx
181
micrococcus infections likely involve :
endogenous strains
182
not generally identified to species level in clinical laboratories because they are rarely clinically significant
micrococci
183
gram staining of micrococci
gram positive
184
morphology of micrococci
tetrads
185
size of micrococci
0.5 -3.5 µm
186
micrococci that produces yellow colonies which may be mistaken for S. aureus
M. luteus
187
micrococci that produce reddish colonies
M. roseus
