Staph and Strep Flashcards
1
Q
Describe the physical structure of Staphylococci?
A
G+ cocci in clusters
2
Q
What is the catalase sensitivity of Staphylococci?
A
Catalase +
3
Q
How does Staphylococci feel about salt?
A
Tolerant, grow up to 9%
4
Q
What two factors are used to differentiate Staphylococci?
A
Hemolysis
Coagulase
5
Q
Clinical presentations of Staphylococcus Aureus caused mainly by bacterial growth?
A
Fununcles
Folliculitis
Non-bullous impetigo
Bacteremia/Wound Infections
6
Q
How are furuncles walled off?
A
Coagulase
7
Q
What is Staphylococcus Aureus folliculitis associated with?
A
Shaving
Contact with Fomite
Complication of Acne
8
Q
Primary cause of acne?
A
Proprionibacterium acnes
9
Q
What is non-bullus impetigo?
A
Infection is the superficial epidermis
Most Common Bacterial Skin Disease
Crusted Blisters
10
Q
Who usually gets non-bullus impetigo?
A
Children and Teens
11
Q
Two most frequent causes of non-bullus impetigo?
A
Staphylococcus Aureus
Strep – Group A
12
Q
Staphylococcus Aureus bacteremis/wound infection is a major concern in…
A
Surgical wounds
Esp. deep incisions that go into muscle, or organ space
13
Q
Clinical presentations of Staphylococcus Aureus typically associated with exotoxin release.
A
Bullous exfoliation
Bullous impetigo
14
Q
What is Bullous exfoliation?
A
Staphylococcal scalded skin syndrome
Intraepidermal splitting and peeling of top layers
15
Q
Who gets bullous exfoliation?
A
Mostly Children
16
Q
Prognosis of Staphylococcus Aureus bullous exfoliation in kids? adults?
A
Kids – Good Prognosis
Adults – Bad – Indicates Bacteremia
17
Q
What is Staphylococcus Aureus bullous impetigo?
A
Fluid filled blisters within the epidermis
Painful
18
Q
Who gets Staphylococcus Aureus bullous impetigo?
A
Kids under 2 years old
19
Q
Cause of Staphylococcus Aureus bullous impetigo?
A
Exfoliative Toxin
20
Q
What is a Staphylococcus Aureus bully?
A
A fluid filled blister in the epidermis
21
Q
Clinical presentation of Toxic Shock Syndrome?
A
Abrupt onset fever
Rash with desquamination
Hypotension
Multisystem, DIC
22
Q
Two types of Toxic Shock Syndrome?
A
Menstrual and Nonmen (M&F-often nosocomial)
23
Q
Cause of Toxic Shock Syndrome?
A
TSST triggers immune rxn
24
Q
Clinical presentation of Staphylococcus Aureus food poisoning?
A
Violent Nausea, Vomiting, Diarrhea
NO Fever
VERY quick (gone within 24)
25
Food poisoning in which you see more vomiting than diarrhea? (3)
B cereus
Staphylococcus Aureus
Norovirus
26
Why is there a different presentation of Toxic Shock and Food Poisoning.
You have lots of Tregs in the gut and few in the bloodstream
27
Typical clinical presentation of Staphylococcus epidermis?
Nosocomial Infections, esp. in surgery
| Biofilm Formation
28
Typical clinical presentation of Staphylococcus saprophyticus?
UTI in young women
| Has specific adhesion for UT epithelia
29
Menstrual TSS is associated with...
Retained tampons
30
Why can't you eradicate Staphylococcus?
Its a part of the normal flora
31
Why is Staphylococcus difficult to treat?
Rapid multi-drug resistance development (ex. MRSA)
32
Four antigens associated with Staphylococcus?
PG
Teichoic Acids
Protein A
Iron Binding Proteins
33
What does Protein A do?
Binds to Fc part of Ab
| Allows bacteria to present "self" antigens to body
34
Toxins associated with Staphylococcus? (6)
```
Coagulase
Hyaluronidase/Streptokinase
Hemolysins
Exfoliative Toxin
TSST-1
Enterotoxins
```
35
What does coagulase do?
Walls off infection
36
What does hyaluronidase/strepto do?
Tissue Invasion
37
Name three types of hemolysins (and targets)
```
alpha toxin (RBCs, plat)
beta toxin (sphingomyelin)
Leukocidin (WBC)
```
38
What is PVL?
Panton-Valentine Leukocidin
| Pore forming toxin associated with MRSA, esp. USA300
39
What does Exfoliative toxin do?
Cleaves N Terminal of desmoglein-1 cell-cell adhesin
| scalded skin syndrome, bullous impetigo
40
What is TSST-1?
A superantigen
| Induces T cells to produce IL1, TNF
41
What are the two superantigens discussed with Staphylococcus?
TSST-1
| Enterotoxins (Food Poisoning)
42
How are superantigen toxins spread from bacteria to bacteria?
On PAIs via transduction.
| Horiz Gene transfer
43
What steps have been made to improve hospital MRSA control?
Better ahnd hygiene
Targeting catheter infections
MRSA-specific detection and decolonization
44
Give an example about how docolonization might pan out?
Chlorhexidine washes
45
How are recurrent Staphylococcus furuncles treated?
drainage and tetracycline
46
Preferred antibiotics for Staphylococcus?
nafcillin
oxacillin
cefazolin
47
How is MRSA typically treated?
```
SxT
Clindamycin
Doxy
Linezolid
IF SEVERE -- Vanco
```
48
How had MRSA treatment be optimized?
Susceptibility Testing
49
Staphylococcus antiobiotic resistance spreads via ___ plasmids.
R-
50
Describe the physical structure of Streptococci and enterococci.
G+ Cocci
| May be oval in chains/Pains
51
Describe the oxgen requirements of Streptococci
Facultative, but prefer 5-10% CO2
52
Streptococci capsules are made with...
Group A -- Hyaluronic Acid
| Polysaccharide
53
Classification of Streptococci is based on...
Hemolysis
Serotyping
Biochemistry
Colonization pattern
54
Difference between alpha and beta hemolysis?
alpha doesn't steal the iron
| beta does steal the iron
55
How does Lancefield serotyping split up Streptococci?
Specific amino-sugar and teichoic acid cell wall antigens
| A-H, K-U
56
Biochemistry informaiton you would look for in classifying Streptococci?
Antibiotic resistance, NaCl tolerance, Bile-esculin
57
Clinical presentation of Group A Streptococci Pyogenes?
Invasive Infections
58
Group A Streptococci Pyogenes is which kind of hemolytic?
Beta
59
Group A Streptococci Pyogenes is sensitive to what antibiotic?
Bacitracin
60
Examples of Group A Streptococci Pyogenes invasive infections (8)
```
Human Erysipelas
Puerpeual Fever
Surgical Sepsis
Scarlet Fever
Streptococcal Toxic Shock Like Syndrome
Necrotizing Fasciitis
Bacteremia
Penumonia (more serious than pneumococcal)
```
61
What is Puerpeual Fever?
Strep of the uterus
62
Symptoms of Scarlett Fever?
Strep bacteremia
Characteristic Diffuse upper body
Rash, Fever, "Strawberry tongue"
63
Usual initial presentation of Group A Streptococci Pyogenes Scarlet Fever?
Scarlet Fever
64
What is necrotizing Fasciitis?
Deep cellulitis that spreads through sub-Q tissue into and through the deep fascia
Can be staph or strep
65
Why can't you culture fluid from a Group A Streptococci Pyogenes fluid bully.
Its the toxin, not the bacteria
66
Examples of Group A Streptococci Pyogenes local infections (8)
Pharyngitis
| Impetigo
67
Symptoms commonly seen in Group A Streptococci Pyogenes pharyngitis.
Fever, Ant. Cerv. Lymphadenopathy, Tonsil Exudate
NO COUGH
Tonsilar Pus and Palletal Petachiae
68
Describe the clinical presentation of Group A Streptococci Pyogenes impetigo.
Crusty, Purulent Blisters
Esp. on Face
ALWAYS non-bullous
69
What do you need to look out for in the weeks following Group A Streptococci Pyogenes? Two manifestations?
Autoimmune responses
Acute Rheumatic Fever
Acute Glomerulonephritis
70
What symptom might you look for in Acute Rheumatic Fever
Heart Valve Damage following Strep Throat
71
What might you expect to see in the labs of a person with acute glomerular nephritis.
Blood and Protein in Urine
72
Reservoirs of Group A Streptococci Pyogenes?
Only Humans (10-20% carrier rate)
73
Epidemiology of strep throat...
| How does it spread, when does it spread, who does it spread to
Nasal Droplets + Contact
Winter
Esp. 6-13 years
74
Epidemiology of Impetigo...
| How does it spread, when does it spread, who does it spread to
Contact, Contiguity, Fomites (Sheets, Pillows)
Summer/Early Fall
Age Peak in Preschool Children
75
Epidemiology of Rheumatic fever...
| How does it occur, when does it spread, who does it spread to
Usually 1-4 weeks after disseminated strep
76
Pathogenesis of (How does it spread, when does it spread, who does it spread to) involved what toxins, Vir Factors (8)
```
M Protein
Hyaluronic Acid Capsule
C Substance
C5a peptidase
Streptokinase
Streptodornase
Exotoxin
Hemolysins
```
77
Effect of M protein?
Cause secretion of heart-reactive antibodies
78
Effect of hyaluronic acid capsule?
Mimics host, so antiphagocytic
79
What si C substance?
A Capsular polysaccharide that enhances invasiveness
80
What is C5A peptidase
Antiphagocytic (anti-complement)
81
What does streptokinase do?
Dissolves fibrin clots
82
What does streptodornase do?
DNAse, high viscosity pus from nucleoprotein
83
What is hyaluronidase?
Spreading Factor
84
Two types of hemolysins seen in Group A Streptococci Pyogenes?
Streptolysin O -- O2 Sensitive
| Streptolysin S -- not O2 Sensitive
85
How is Group A Streptococci Pyogenes controlled
Prevent spread -- pasteurize milk, isolate carriers from patients
Treat acute infections early
86
How are Group A Streptococci Pyogenes treated?
All sensitive to PenG
| If necessary, anti-inflammatories, rest
87
Species that makes up Group B Strep
S agalactiae
88
Group B strep is ____ hemolytic
It is cAMP _____
and Bacitracin _______
Beta
Positive
Resistant
89
Clinical presentation of Group B strep is?
Neonatal Sepsis/Pneumonia
Neonatal Meningitis
Resp. Distress Syndrome
Bacteremia
90
Who gets Group B strep?
Infants, IC, Elderly
91
How is Group B strep usually spread?
Spread from infected mothers to baby in delivery
92
How is Group B strep controlled?
Screen Before Delivery
If +, 3rd gen Ceph or Amp+Strep
Give baby prophylactics
93
Group D strep consist of....
Enterococci and S bovis
94
Group D strep are ______ hemolytic
Mostly Non-
| Sometimes alpha
95
Clinical presentation of Group D strep?
Nosocomial Infections
Bacteremia
Endocarditis
UTI
96
How is Group D strep typically transferred?
Hands of hospital workers
| Portal of entry --- GI tract/bacteremia from colon lesions
97
How is Group D strep controlled? (or not controlled)
Enterococci resistant to beta-lactams, SxT
| Treat SYNERGISTICALLY with penicillin and aminoglycoside
98
Why might you consider/not consider using vanco to treat enterococcus?
It should work, but there is a high frequency of vancomycin resistance in the US
99
Infective endocarditis is typically caused by...
Staphylococci and streptococci
100
Oral (Viridans) Streptococci is ___ hemolytic
| optochin _________
Alpha
| Resistant
101
Most common clinical manifestation of Oral (Viridans) Streptococci?
Sub-acute bacterial endocarditis
(esp after tooth surgery)
Heart murmur, Weaknes, Anemia, Embolism
102
Prognosis for an untreated Oral (Viridans) Streptococci infection?
100% fatal.
103
Who would you expect to get Oral (Viridans) Streptococci infection?
Someone who has recently had a dental procedure
104
How is Oral (Viridans) Streptococci treated?
Long term, High Dose antibiotic
105
How is Oral (Viridans) Streptococci controlled?
Prophylactic antibiotics before/after oral surgery
106
Strep pneumoniae is ___ hemolytic and optochin _____
Alpha
| Sensitive
107
Strep pneumoniae physical structure...
Diplococci with large polysaccharide capsule
108
What is a quellung reaction?
Add polyvalent antiserum against capsule + Sputum
If Strep pneumoniae present, capsule will swell
Visualize by negative stain
109
Clinical presentation of Strep pneumoniae?
Lobar Pneumonia with Fever, Chills, Sharp Pain
Mental Confusion
Increased Leukocytes
May spread to Middle ear (#2 otitis media)
May spread to meninges (#1 for middle age adults)
110
Describe lobar pneumonia.
Consolidation of one+ lobes
| Bronchi often open
111
Describe bronchopneumonia
Patchy, Peribronchial Thickening
| Consolidation of Alveoli
112
Describe Interstitial pneumonia
Inflammation and edema of interstitial tissue of the lung
| Fibrosis
113
Three risk factors associated with Strep pneumoniae?
Mucus accumulation
Alcohol/Drug Use
General Debility (Flu, anemia, COPD)
114
Pathogenesis of Strep pneumoniae?
Colonization of tissues
Polysac. capsule and debilitated host are critical
IgA Protease
115
How is Strep pneumoniae controlled?
Vaccines available to prevent pneumococcal disease
