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19 Cards in this Set
- Front
- Back
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What are the 5 important diseases caused by Streptococci?
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1. Strep Throat
2. Rheumatic Fever 3. Scarlet Fever 4. Necrotizing Fasciitis 5. Streptococcal Toxic Shock Syndrome |
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Are Strep. Gram Positive or Negative?
Catalase - or +? |
1. Gram Positive
2. Catalase negative |
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What are 3 main subdivisions of Streptococcus?
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1. Alpha Hemolytic (Streptococcus pneumoniae)
2. Beta Hemolytic (Group A/Group B Strep) 3. Gamma Hemolytic (Enterococcus) |
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What are the two most important groups of Beta Hemolytic Strep?
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1. Group A
2. Group B |
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Streptococcus pyogenes is which Beta Hemolytic group?
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Group A
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What are the 4 major virulence factors of Group A Strep?
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1. Exotoxins
2. M Protein 3. Hyaluronidase 4. C5a peptidase |
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What is the function of M Protein in Group A Strep?
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M Protein prevents Step from being phagocytosed and destroyed by neutrophils
- Does this by interfering with complement (c3b) |
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What are 2 primary locations where Group A Strep colonizes?
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1. Oropharynx (usually of young children)
-Givens Pharyngitis 2. Skin |
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What are 5 main cutaneous manifestations of Group A Strep?
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1. Scarlet Fever - complication of step. pharyngitis, that was phage infected with pyrogenic exotoxin
2. Impetigo - contagious yellow, crusty lesions 3. Necrotizing Fasciitis - infection deep in subcutaneous tissue. Must be treated surgically. 4. Erysipelas - Acute superficial cellultis 5. Cellulitis - involves deeper subcutaneous tissues |
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What are the 3 Post Infectious Sequelae that can develop in Group A Strep?
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1. Rheumatic Fever
2. Acute Glomerulonephritis 3. Streptococcal Toxic Shock Syndrome |
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What are symptoms and cause of Rheumatic Fever?
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Symptoms: Arthritis, Carditis, chorea (NS disorder), and subcutaneous nodules
Cause: Post Infection Sequelae. Not exactly understood. Thought to be autoimmune in nature. |
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What are symptoms and cause of Acute Glomerulonephritis?
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Symptoms: Dark urine, Hypertension, Granular accumulation of Ig's in Kidney
Cause: Post Infection Sequelae, Autoimmune in nautre |
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What are symptoms and cause of Streptococcal Toxic Shock Syndrome?
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Symptoms: Multisystem toxicity following soft tissue infection progressing to shock
Cause: Non-Specific stimulation of T-Cells by "Superantigen" |
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How does one diagnose/identify strep?
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1. Culture, perform antibody test to Group A Carbohydrate Antigen
2. Look at Gram Postive, Catalase +/- |
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What is Group A Strep Treated with?
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- Penicillin for Pharyngitis
- used to PREVENT rheumatic fever because infection would be cleared normally in same amount of time |
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Streptococcus agalactia is in which group?
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Group B Strep
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How can Group A be readily distinguished from Group B?
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Group A = Bacitracin Sensitive
Group B = Bacitracin Resistant |
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What is Group B Strep's major defense against immune system?
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Sialic Acid Capsule
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What does Group B colonize, how is it spread?
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- Colonizes lower gastrointestinal and genitourinary tract
- Often transferred via pregnancy - Leading cause of NEONATAL INFECTION |
