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14 Cards in this Set
- Front
- Back
What gram type are the staphs? |
Gram + cocci |
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What enzyme do the Staphs produce? |
Catalase
Breaks down Hydrogen Peroxide |
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What are the general features of Staph? |
Pyogenic (Pus forming)
Survive on objects
Common cause of community acquired and hospital acquired infections
Antibiotic resistance a problem (MRSA) |
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**Catalase test helps us determine presence of which two gm + cocci?
Coagulase test helps us determine presence of which 1 and 2 staphs? |
Catalase---> - is Strep + is Staph
+ Staph is coagulase tested Coagulase---> Coagulase - strep are Epidermidis and Saprophyticus
(only Saprophyticus is Novobiocin susceptible)
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*Case:
Fever, low back pain, aches, chills, abscess, high white blood cell count.
Gram + cocci in clusters
Osteomyelitis
Resistant to penicillin
Positive for enterotoxin A |
Staph. Aureus |
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** What are the 2 superantigens that can cause Toxic Shock Syndrome and how do they work? |
Enterotoxin and Toxic Shock Syndrome Toxin
Connect MHC class 2 with T-cells causing cytokine storm which results in hypotension and breakdown of organs
This are caused by toxins |
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*Describe this pathologies:
SSSS (Staphylococcal Scalded Skin syndrome), caused by what? |
Caused by exfoliative toxins A and B
Causes extensive sloughing of skin. |
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**Name and describe the cytokines of cytokine storm (in Toxic Shock Syndrome)
Toxic Shock syndrome caused by exotoxins that are superantigens |
IL-1 = Fever TNF-a = Fever
TNF-a and TNF-b = hypotension, capillary leakage INF-gamma and IL-2 = rash
INF is (Interferon) |
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***Staphylococcal food poisoning is caused by what and what are its serotypes? |
Staphylococcal food poisoning (acute gastroenteritis) is caused by:
Staphylococcal enterotoxin with serotypes (SEA, SEB, SEC)
It is active in presence of heat! |
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*Treat Staph aureus with what drug types? |
Penicillins and Cephalosporins (ie nafcillin) that are b-lactamase resistant
Not effective against MRSA |
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**What binding protein makes Staph resistant to Methicillin? |
Penicillin-binding protein 2a (PBP2a)
PBP2a is encoded on different cassettes on Staph chromosome (SCCmec)
mec is gene that transcodes for transpeptidase
((Essentially, MRSA makes new transpeptidase (PBP2a) that does not bind methicillin, so the bacteria continues to make peptidoglycan and lives!)) |
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**What are the 2 Coagulase - staph? |
Often referred to as CoNS, they are:
Staph Epidermidis Staph Saprophyticus |
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**What staph?
Catalase + Coagulase - Novobiocin sensitive
Where can it be found? |
Staph epidermidis
Often found on plastic prosthetics |
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**What staph?
Catalase + Coagulase - Novobiocin RESISTANT
**Where is it often found? |
Staph saprophyticus
often found in Genitourinary of Female (UTI's in women) |