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16 Cards in this Set
- Front
- Back
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Is Staph. aureus Gram Positive/Negative?
Aerobic/Anaerobic? Catalase Positive/Negative? |
1. Gram Positive
2. Aerobic 3. Catalase Positive |
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What distinguishes Staph. aureus from other Staph. species?
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It is coagulase positive
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What are 6 main types of Virulence Factors that Staph. aureus has?
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1. Alpha Toxin (pore forming)
2. Panton-Valentin leukicidin (Beta pore forming toxin) 3. Toxic Shock Syndrome Toxin (Toxic Shock) 4. Exfoliative Toxin (Scalded Skin Syndrome) 5. Enterotoxin (Food Poisoning) 6. Capsule |
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Is adaptive immunity effective against Staph?
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No - it can be gotten multiple times
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What are the 3 patterns of Staph carriers?
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1. Persistent Carriers (20%)
2. Intermittent Carriers (60%) 3. Almost Never Carriers (20%) |
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What are 3 categories of clinical diseases caused by Staph?
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1. Cutaneous Lesions
2. Systemic and deep seated 3. Toxin-Mediated |
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What are 4 examples of cutaneous manifestations of S. aureus?
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1. Staphylococccal Scalded Skin Syndrome - Sloughing off of skin in young kids. Caused by S. aureus that expressed EXFOLIATIVE TOXINS
2. Impetigo - Blisters (Similiar to Group A Strep) 3. Folliculitis - Infection of hair follicle 4. Carbuncles - Mutiple boils (furnucles) that coalesce; associated with fever/chills |
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What serious complication can occur if S. aureus causes bacteremia?
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Endocarditis, destruction of heart valves
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What systemic presentations does S. Aureus show?
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1. PNEUMONIA
2. Bacteremia 3. Osteomyletis and Septic Arthritis 4. Endocarditis 5. Empyema (collection of pus in lung pleura) |
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How can S. aureus cause food poising?
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- If enterotoxin gets into food supply
- Incubation period only 4 hours |
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Does S. epidermidis usually cause disease?
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- No, common flora
- But can cause catheter and shunt infections, prosthetic joint infection, artificial heart valve infections |
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What clincal diseases can S. epidermidis cause?
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1. Endocarditis of artificial heart valves
2. Catheter/shunt infections 3. Prosthetic Joint infections 4. UTI's |
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Can Penicillin be used against Staph?
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No because of acquisition of penicillinases. Too much resistance.
- Methicillin or Vancomycin must be used |
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What is the main antibiotic used against Staph?
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- Methicillin/Oxacillin for MSSA
- Vancomycin for MRSA (resistance to all beta lactams, due to mecA gene endcoding altered PBP) |
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For very resistant forms of Staph, what antibiotic is used as a last resort?
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Vancomycin
- But have had a few reports of Vancomycin resistant cases in past few years |
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What are differences between Hospital Acquired (HA) MRSA and Community Acquired (CA) MRSA?
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1. Where Staph was obtained
2. CA less drug resistant |
