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24 Cards in this Set
- Front
- Back
3 major species of Staphylococci
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S. aureus
S. epidermidis S. saprophyticus |
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how do you differentiate between Staphylococcus and Streptococci
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Catalase test
Gram stain Culture |
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Is Staphylococcus gram +/-?
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Gram +
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which of the Staphylococci are catalase +
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S. aureus
this is diagnostic |
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which of the Staphylococci are coagulase positive?
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S. aureus
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If the lab calls you to tell you:
Gram + bacteria Coagulase + cocci in clusters what is your diagnosis? |
S. aureus
|
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what are the virulence factors of S. aureus?
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Mucopeptide: toxic, antiphagocytic
Coagulase: diagnostic Cell associated: capsule, protein A, Fibronectin-binding protein, collagen-binding protein, only species with protein A |
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where does the transmission of S. aureus usually occur?
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humans, especially skin, nose, and perineum
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what types of disease is caused by S. aureus?
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Boils
Skin sepsis Postoperative wound infection Scalded skin syndrome Catheter associated infection Foodborne infection septicemia Endocarditis Toxic Shock Syndrome Osteomyelitis Pneumonia |
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True or False
S. aureus is non-fastidious capable of aerobic or anaerobic respiration |
True
|
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how is S. aureus identified in the lab?
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white/golden colonies on blood agar
Catalase + Coagulase + Most strains ferment MANNITOL anaerobically |
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what is the action of Protein A in the cell wall of S. aureus?
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it is bound to the mucopeptide of the cell wall > interacts with IgG antibodies reducing opsonization and causing local activation of complement
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the diseases caused by S. aureus are caused by what?
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1. Exotoxin release
2. Direct organ invasion |
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what are the diseases caused by S. aureus exotoxin release?
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1. Gastroenteritis
2. Toxic Shock Syndrome 3. Scalded skin syndrome |
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what are the diseases caused by S. aureus direct organ invasion?
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1. pneumonia
2. meningitis 3. osteomyelitis 4. acute bacterial endocarditis 5. septic arthritis 6. bacteremia/sepsis 7. skin infections 8. urinary tract infections |
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what is the drug of choice for treatment of MRSA?
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Vancomycin
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how is S. epidermis identified clinically?
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white colonies on blood agar
Catalase + Coagulase - Mannitol not fermented anaerobically |
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what type of disease is caused by S. epidermis?
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opportunist pathogen associated with device related sepsis
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what are some specific diseases caused by S. epidermis?
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catheter related sepsis
Prosthetic valve endocarditis infection of artificial joint shunt infections UTI Sternal wound osteomyelitis MRSE |
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Is S. epidermis coagulase negative/positive
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Negative
this is differential diagnostic between S. aureus & S. epidermis |
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what may assist S. epidermis in colonization of plastic implants?
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extracellular slime production
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Is Staph Saprophyticus part of the normal flora of humans.
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YES
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what microbe is the leading cause of UTI in sexually active women?
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Staph. Saprophyticus
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How is S. Saprophyticus differentiated from S. epidermidis?
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S. Saprophyticus is Catalase - and Coagulase -
S. epidermidis is Catalse + and Coagulase - |