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49 Cards in this Set
- Front
- Back
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Streptococci:
- Gram what? - Catalase what? |
Positive
Negative |
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Alpha Hemolysis:
- what happens here? - appearance? - which streptoccocus? x2 |
Partial RBC lysis
Greenish discoloration Streptococcus Pneumoniae "Viridians" Strept. |
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Beta Hemolysis:
- what happens here? - appearance? - which streptococcus? x2 |
Complete lysis of RBC's
Clear zone GAS (Streptococcus Pyogenes) GBS (Streptococcus Agalactiae) |
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Gamma Hemolysis:
- what happens here? - appearance? |
No RBC lysis
No change |
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Antigenic Classification:
- Group A Streptococci (GAS) - Group B Streptococci (GBS) - Group D Streptococci (GDS) - Non-groupable |
Streptococcus pyogenes
Streptococcus agalactiae Enterococci Streptococcus pneumoniae |
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S. Pyogenes:
- gram what - oxygen dependency - cell wall antigens x2 - hemolytic activity - catalase - capsule? |
Positive
Facultative M-proteins Group A carbohydrates Beta hemolytic (complete lysis) Negative Usually |
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S. Pyogenes ASYMPTOMATICALLY colonize where?
Especially prevalent in which population group? |
Upper respiratory tract
Children 5-15 |
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S. Pyogenes can colonize TRANSIENTLY where?
This type of colonization is higher with whom? x2 |
Transient Skin Carriage
Open wounds or skin disease Live in areas with high S. Pyoderma infections |
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In patients with S. Pyogenes pharyngitis, what is a common way for bacterium spread?
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Respiratory droplets (pharyngitis),
or food or water |
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Describe the ability of S. Pyogenes to survive on dry surfaces?
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Can do it for a long time.
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In contrast to other Streptococci diseases, what is unique and distinguishing about S. Pyogenes?
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Can cause disease in otherwise healthy individuals
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T/F - Most Pharyngitis is caused by GAS Beta Hemolytic.
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False,
mostly viral |
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What is "Strep Throat," and what are the associated symptoms? x7
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Pharyngitis caused by S. Pyogenes
Sore Throat HA Erythematous Posterior Pharynx +/- Exudate Pharyngitis Fever & Malaise |
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What are some suppurative complications from Pharyngitis? x4
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Peritonsilar Cellulitis or Abscesses
Retropharyngeal Abscesses Otitis Media Mastoiditis |
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What kind of complication is Acute Rheumatic Fever?
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Non-suppurative complication of Pharyngitis
Not a complication of skin infections |
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What are the symptoms of Acute Rheumatic Fever? x3
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Polyarthritis
Carditis Chorea |
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What is the treatment of Acute Rheumatic Fever?
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Prevention by treating Pharyngitis
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What kind of complication is scarlet fever?
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Non-suppurative complication of Pharyngitis AND Skin infection
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What is the cellular/microbiological etiology of scarlet fever?
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Exotoxins from bacteriophage infected strains (lysogenic conversion) of S. Pyogenes
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Symptoms of scarlet fever. x4
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Scarlet-red rash (spares face)
Fever Skin desquamation (post rash) Strawberry tongue |
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Describe the complication of acute glomerulonephritis.
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Non-suppurative complication of pharyngitis or pyoderma
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Symptoms of glomerulonephritis. x4
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Inflammation of renal glomeruli with:
HTN Edema Hematuria Proteinuria |
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Prognosis of acute glomerulonephritis.
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Excellent, especially for kids.
Some adults have progressive, irreversible loss of renal function |
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List three skin diseases associated with S. Pyogenes.
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Impetigo (pyoderma)
Cellulitis Erysipelas |
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Describe the progression of impetigo (pyoderma)
Common in? |
Starts out as red papules
Develops into vesicles with clear, yellow contents Develops into pustules filled with bacteria Common in children (around mouth) associated with poor hygiene & moist climate |
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Describe cellulitis.
Possibly from what assault? Complications? |
Infection involving Skin & deeper subcutaneous tissue.
Burns, surgical wounds, illicit drug use Can lead to bacteremia |
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Describe erysipelas.
What other symptoms usually accompany erysipelas? x5 |
Infection of superficial skin (dermis) only.
Fever Inflammation Lymph node enlargement, Local pain Chill |
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S. Pyogenes Pneumonia:
- usually preceded by what? x2 - symptoms x3 - associated by preceding what Dz? - mortality? |
Viral infection
Chronic pulmonary disease Fever Chills Productive cough with Blood-tinged sputum Bacteremia (15%) Rate is 30% |
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Streptococcus Toxic Shock Syndrome
- transmission? - associated with what strains? - pathogenesis? |
Penetration of skin lesion
(chickenpox blister, cut, surgery...) Strep. pyogenes strains that cause skin disease (NOT the ones that cause pharyngitis) GAS multiply at site of infection, producing TOXINS |
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Streptococcus TSS symptoms. x5
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Bacteremia
Impaired clotting Toxins & shit in body Constitutional symptoms (fever, chills, malaise, N/V/D) Hypotension |
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Most patients with Streptococcus TSS will also eventually develop what horrible Dz?
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Necrotizing fascitis
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What are the three major differences with Streptococcus TSS when compared to Staphylococcus TSS?
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1. Uncommon rash/desquamation
2. Frequent bacteremia 3. Higher mortality - 50% (staph is 5%) |
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When to suspect TSS?
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Pt has
INFECTED SKIN LESION + FEVER (with or without PAIN) |
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Treatment for Streptococcus TSS
- Antibiotics used? - Tx protocol |
Clindamycin + PCN
Prompt & Aggressive for EXPLORATION & DEBRIDEMENT Antibiotics with IV fluids (IV to counteract caplillary leak) |
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T/F - The use of PCN is effective against Streptococcus TSS.
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False
Not very effective at killing large numbers of slow growing organisms Thus, stack with clindamycin |
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Necrotizing Fasciitis course of disease.
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Enter through trauma or trivial wounds
Skin involved LATER on Toxins destroy tissue (3 cm/hr) Bacteremia Shock, Multiple organ failure Death |
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What are the symptoms of necrotizing fascitis?
Which one will bring the patient in to the hospital? |
Flu-like symptoms
Diarrhea Vomiting PAiN localized and out of proportion to wound (brings pt in) |
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Treatment for necrotizing fasciitis. x3
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Aggressive antibiotics
Surgical Debridement Symptoms treatment |
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What is M protein?
What does it do? How does it do it? x3 |
Major virulence factor
ANTI-PHAGOCYTIC (against neutrophils) Binds fibrinogen Sequesters C4b (decreases C3b deposition) Sequesters Factor H (decreases C3b deposition) |
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In streptococcus pyogenes, what does streptolysin S & O do.
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Lysis of erythrocytes, leukocytes, and platelets
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List all the Strep. Pyogenes virulence factors and give brief description of their actions. x8
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M Protein (antiphagocytic)
Capsule (antiphagocytic) DNase ( for better bacterial spread) Streptokinase (for spread) Lipoteichoic acid (shock) Superantigen (shock) Streptolysin S & O (kills immune cells) C5a peptidase (degrades C5a, thus impairing chemotaxis) |
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What 2 TYPES of complications can arise from Strep. Pyogenes Pharyngitis?
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Supparative
Non-Supparative |
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List the NON-supparative complications of Strep. Pharyngitis and include what differentiates them. x3
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Acute Rheumatic Fever
(non-supparative complication of Strep pharyngitis ONLY, and not from skin infections) Scarlet Fever (complication of BOTH strep pharyngitis AND skin infecitons) Acute Glomerulonephritis (complication of BOTH strep pharyngitis OR pyoderma) |
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Necrotizing Fascitis
- initial symptoms - Sx that usually brings the pt to seek Tx |
Initial
- flu-like symptoms - N/V/D Localized Pain Out of Proportion to Apparent Wound/Trauma |
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Streptococcus pyogenes Bacteremia
- especially dangerous if? - RARELY follows what? - OFTEN follows what? - Mortality rate? |
if consequence of wound infections, pneumonia, NF, & TSS
rarely follows localized infections complication of NF or TSS 40% in pts with NF/TSS and Bacteremia |
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Strep. Pyogenes Bacteremia
- symptoms x3 |
Fever that is very high
Chills Exhaustion |
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Strep. Pyogenes Treatment
- for impetigo |
ORAL
Cloxacillin, cephalexin, cefadroxin, & Cefaclor TOPICAL Mupirocin |
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Strep. Pyogenes Treatment
- For other infections EXCEPT TSS, NF, and impetigo |
PCN
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Strep. Pyogenes Treatment
- for TSS and NF |
Clindamycin + PCN
IV gluids IV gamma globulins (neutralize toxins) Surgical debridement |
