9-2 Staph/Strep/Enterococci Flashcards Preview

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Flashcards in 9-2 Staph/Strep/Enterococci Deck (39)
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1

[T or F]

Micrococci are NOT associated with disease

TRUE

2

Defects in _______ and _________ can predispose an individual to [Staph Aureus] Infection.

Name the 6 Dz that can cause Leukocyte Chemotaxis

Defects in [Leukocyte Chemotaxis] and [Ab Opsonization] can predispose an individual to Staph Aureus.

Name the 4 Dz that can cause Leukocyte Chemotaxis

"A [DJ from DR] can ruin ur [Leukocyte Chemotaxis]"

1. Down Syndrome
2. Job's Syndrome
3. DM
4. Rheumatoid Arthritis

3

Name the 6 usual sites of infection for [Staph Aureus]

Staph Aureus typically infects areas in which it is Normal Flora
1) Skin
2) Anterior Nares
3) Throat
4) GI
5) Vagina
6) Urethra

4

Carbuncle

B: Two places they're mostly found

an Abscess larger than a boil with 1 or more opening draining pus onto the skin

B:
-Back
-Nape of the Neck

5

3 Toxin-Mediated Infections associated with [Staph Aureus]

1. Scalded Skin Syndrome (neonates and children under 4)
2. Toxic-Shock syndrome
3. Food Poisoning

6

Panton-Valentine Leukocidin (PVL)

[Staph Aureus] enzyme that alters leukocyte permeability to allow cations to pass---> Leukocyte Destruction

7

STAPH AUREUS VIRULENCE FACTOR :
a-hemolysin (3)

1. Lyses RBC of several animals

2. Dermonecrotic on SubQ injection

3. Leukocyte toxicity

8

STAPH AUREUS VIRULENCE FACTOR :
B-hemolysin (2)

ºSphingomyelinase --> varying hemolysis of RBC due to differences in membrane sphingomyelin content

ºProduces HOT-COLD lysis in which hemolysis is ENHANCED at COLD temperatures after 35ºC incubation

9

STAPH AUREUS VIRULENCE FACTOR :
DELTA-hemolysin (3)

*Produced by 97% [Staph Aureus]

*acts as surfactant to disrupt cell membrane and form channels that increase over time---> leakage

*Some [coag-NEG Staph] can use this to cause NEC in neonates

10

STAPH AUREUS VIRULENCE FACTOR :
Hyaluronidase

Hydrolyzes intercellular matrix of acid mucopolysaccharides in tissue --> allows [S.Aureus] to spread to adjacent tissue

11

STAPH AUREUS VIRULENCE FACTOR :
Phospholipase C

A: 2 types of pt its found in

B: Function

STAPH AUREUS VIRULENCE FACTOR
A: Found in pt with ARDS & DIC

B: Causes tissues to become more susceptible to damage by [bioactive complement components]

12

A: List the 3 Superantigen Toxins of [S.Aureus]

B: Name the 2 Biologic Characteristics they all display

A: [PYROGENIC TOXIN SUPERANTIGENS]
1) Toxic Shock Syndrome Toxin -1 (TSST1)
2) Strep Pyrogenic Exotoxins (SPE)
3) [Strep superantigens]

B: •All of these induce Polyclonal T-cell proliferation
•Enhance lethal effects of small amounts of endotoxin

13

A: Which bacteria is the 2nd most common cause of uncomplicated cystitis in [women in college/child-bearing age]?

B: What's the FIRST most common cause?

C: The bacteria in (A) is RESISTANT TO ______ but susceptible to ______

A: 2nd most common cause= Staph Saprophyticus

B: E.Coli is 1st

C: [Staph Saprophyticus] is [RESISTANT TO NOVOBIOCIN] but [susceptible to Furozolidone]

14

A: What is special about [Staph Lugdunensis]?

B: Where does this bacteria typically colonize?

A: Only species that is both [PYR AND Ornithine Positive]!

B: Human Inguinal Area

15

A: What is [SCCmec]

B: What does the mecA gene do?

A: The [SCCmec] is a [Staph Aureus] mobile chromosome that encodes for mecA

B: mecA is a gene that alters [Penicillin Binding Protein] ---> [PBP2a] which allows [Staph Aureus] to become [Methicillin/B-lactam Abx RESISTANT]

16

3 Substances that can GENERATE ERRORS during a [PCR MRSA nasal test] for pts?

1. Whole Blood

2. Mucus

3. Nasal Spray

17

Which bacteria is associated with [Skin and Soft Tissue Infection]

MRSA

18

Streptococci prefers [______ atmosphere] and require ______ media to grow

Streptococci prefers [Anaerobic/CO2 atmosphere] and require COMPLEX media to grow

19

A: Why does [Strep Pyogenes] reoccur?

B: How is it transmitted?

A: [Strep pyogenes] reoccurs due to the lack of an Antibody to the M-protein

B: [Strep Pyogenes] is transmitted by Respiratory Droplets

20

A: What bacteria is Scarlet Fever associated with?

B: What toxin causes this?

C: Explain the symptom manifestation

D: When does it appear exactly?

E: What key characteristic sign should it display?

F: When does it resolve?

A: Scarlet Fever is associated with [Strep Pyogenes - Group A]

B: Caused by Erythrogenic exotoxin

C:
1st starts as Rash w/tiny red bumps on chest, abdomen and behind ears BUT SPARES THE FACE

D: Appears 12-48 hours after the fever

E: Fine, red and rough-textured BLANCHES on pressure

F: Rash resolves 3-4 days after onset and then DesQuamation begins

21

What's the difference between [Staph Aureus Toxic Shock] and [Strep Pyogenes Group A Toxic Shock]

Unlike pt with [Staph Aureus Toxic Shock], [STREP Pyogenes Group A Toxic Shock] will result in a Positive Culture

22

A: Puerperal Sepsis

B: Who is this typically seen in?

A: [Strep Pyogenes] colonizing the genital tract or from Ob/Gyn Doc invade upper genital tract --->
[Strep Pyogenes Group A Toxic Shock] / [necrotizing fasciitis] /lymphangitis

B: Seen in women post delivery or post abortion

23

A: List the 2 Main sx of [Post-Streptococcal Sequelae]

B: Which strep is this associated with?

1. Rheumatic Fever

2. Glomerular Nephritis

B: [Strep Pyogenes Group A]

24

A: Rheumatic Fever Description

B: When does this reoccur?

C: List 4 symptoms

D: This is 1 of the 2 symptoms for what syndrome?

A: Nonsuppurative inflammation occurring 1-5 weeks after [Strep pharyngitis]

B: Attacks reoccur into adulthood

C:
1.Fever
2. [SubQ Nodules]
3. Chorea
4. [Characteristic Cardiac lesions - Aschoff bodies and mitral valve damage]

D: Syndrome: [Post-Streptococcal Sequelae]

25

A: Acute Glomerulonephritis 2º to [Post-Streptococcal Sequelae] occurs when? Etiology?

B: Name 4 sx

C: Which bacteria causes this?

D: Why does this reoccur consistently?

A: Occurs AFTER a skin/respiratory infection. [Antigen + Ab + C] all deposit in the glomeruli

B:
a) edema
b) HTN
c) hematuria
d) proteinuria

C: [Strep Pyogenes Group A]

D: [Strep Pyogenes] has different [M Proteins] which allows for it to evade the immune system upon reoccurrence and some [M proteins] will illicit a more nephropathogenic etiology

26

A: Compare Virulence Factors [Streptolysin S vs. Streptolysin O] in ______ bacteria

B: What are 3 other [Virulence factor enzymes] for this bacteria?

C: What 2 enzymes allow this bacteria to spread into other tissues?

[Strep Pyogenes]
A: [Streptolysin S]= O2 stable / non-antigenic
vs.

[Streptolysin O] = O2 Labile / [incites ASO Antibody production]
---------------------------------------------------------------------------------
B: [C5a peptidase] / Hyaluronidase / Streptokinase

C: Streptolysin and Streptokinase allow [Strep Pyogenes] to spread into other tissues

27

A: [M Protein] binds to ______ cells and allows bacterial ______. It's Antiphagocytic because it DEGRADES ______.

B: How is the bacteria eradicated? (4)

A: [M Protein] binds to epidermal cells and allows bacterial survival. It's Antiphagocytic because it DEGRADES [COMPLEMENT C3b].

B:
1) Antibodies to [M protein] activate complement and then kill the bacteria
2) Penicillin/Ampicillin/Amoxicillin = NO RESISTANCE WORLDWIDE
3) Cephalosporins

4) Erythromycin (Use in Penicillin allergic pt)

28

A: [Strep Agalactiae GBS - (Group B Strep)] is normal flora in what 3 areas?

B: What sx does it cause in Adults?

C: Early Onset Neonatal Sx

D: Late Onset Neonatal Sx

E: How does Sialic Acid play a role?

A:
-Throat
-Vagina
- [GI tract]

B: Skin and wound infections (Diabetic Adults)

C: Early Onset Neonatal (1st week of life) = [Bacteremia/ Meningitis/ PNA]

D: LATE Onset Neonatal (1 week-3 mo.)= Bacteremia w/Meningitis

E: Sialic Acid on Polysaccharide Capsule inhibits Complement --> allows GBS to multiply

29

Other Beta-Hemolytic Strep:

Group C (3)

1. Veterinary Infections

2. College Pt Pharyngitis

3. Sepsis

30

Other Beta-Hemolytic Strep:

Group F

Associated with Abscesses