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Flashcards in Staph and Strep Deck (115)
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1

Describe the physical structure of Staphylococci?

G+ cocci in clusters

2

What is the catalase sensitivity of Staphylococci?

Catalase +

3

How does Staphylococci feel about salt?

Tolerant, grow up to 9%

4

What two factors are used to differentiate Staphylococci?

Hemolysis
Coagulase

5

Clinical presentations of Staphylococcus Aureus caused mainly by bacterial growth?

Fununcles
Folliculitis
Non-bullous impetigo
Bacteremia/Wound Infections

6

How are furuncles walled off?

Coagulase

7

What is Staphylococcus Aureus folliculitis associated with?

Shaving
Contact with Fomite
Complication of Acne

8

Primary cause of acne?

Proprionibacterium acnes

9

What is non-bullus impetigo?

Infection is the superficial epidermis
Most Common Bacterial Skin Disease
Crusted Blisters

10

Who usually gets non-bullus impetigo?

Children and Teens

11

Two most frequent causes of non-bullus impetigo?

Staphylococcus Aureus
Strep -- Group A

12

Staphylococcus Aureus bacteremis/wound infection is a major concern in...

Surgical wounds
Esp. deep incisions that go into muscle, or organ space

13

Clinical presentations of Staphylococcus Aureus typically associated with exotoxin release.

Bullous exfoliation
Bullous impetigo

14

What is Bullous exfoliation?

Staphylococcal scalded skin syndrome
Intraepidermal splitting and peeling of top layers

15

Who gets bullous exfoliation?

Mostly Children

16

Prognosis of Staphylococcus Aureus bullous exfoliation in kids? adults?

Kids -- Good Prognosis
Adults -- Bad -- Indicates Bacteremia

17

What is Staphylococcus Aureus bullous impetigo?

Fluid filled blisters within the epidermis
Painful

18

Who gets Staphylococcus Aureus bullous impetigo?

Kids under 2 years old

19

Cause of Staphylococcus Aureus bullous impetigo?

Exfoliative Toxin

20

What is a Staphylococcus Aureus bully?

A fluid filled blister in the epidermis

21

Clinical presentation of Toxic Shock Syndrome?

Abrupt onset fever
Rash with desquamination
Hypotension
Multisystem, DIC

22

Two types of Toxic Shock Syndrome?

Menstrual and Nonmen (M&F-often nosocomial)

23

Cause of Toxic Shock Syndrome?

TSST triggers immune rxn

24

Clinical presentation of Staphylococcus Aureus food poisoning?

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