Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
38 Cards in this Set
- Front
- Back
|
Staphylococcus: cellular morphology
|
form clusters, have fibronectin, has a capsule. S. epidermis has thick capsules and a protective biofilm.
|
|
|
Staphylococcus: biological properties
|
xxx
|
|
|
Staphylococcus: culture needs
|
hardy bacteria that can grow in high salt and resist antibiotics. Blood agar.
|
|
|
Discuss the laboratory characteristics that differentiate Staphylococcus aureus from the opportunistic staphylococci of lower virulence.
|
Coagulase positive vs. negative.
|
|
|
What toxins and enzymes are responsible for the damage done by Staphylococcus aureus to the body tissues? (8)
|
1 capsule, 2 protein A, 3 coagulase, 4 catalase, 5 immunologic disguises (Protein A, coagulase), 6 membrane-damaging toxins, 7 exotoxins, 8 resistance to microbial agents
|
|
|
add the case study
|
xxx
|
|
|
Name the 4 genera of cocci (Kids Playing Catch on Freeways Get Smashed)
|
Staphylococcus Streptococcus Enterococcus Neisseria
|
|
|
"staph", def
|
Staphule= cluster of grapes
|
|
|
"strep", def
|
streptos = chain
|
|
|
catheter infection is most likely what organism?
|
Staph. (UTI is E. coli)
|
|
|
"aureus",def
|
golden
|
|
|
Compare Staph aureus and staph epidermis with respect to: color, mannitol, coagulase
|
AUREUS: golden yellow, ferments mannitol, coagulase positive. STAPH EPIDERMIS: white, no mannitol, coagulase negative (Aureus is the bad guy, so it eats and ruins everything)
|
|
|
coagulase, def. What is the appearance of a positive test?
|
an enzyme that clots blood plasma. appears clumpy in the bottom of a test tube.
|
|
|
Staph vs. Strep: metabolism
|
STAPH: facultative aerobes. STREP: anaerobic, aerotolerant.
|
|
|
Staph vs. Strep: catalase
|
STAPH: have catalase. STREP: no catalase.
|
|
|
Staph vs. Strep: Which are the most resistant?
|
Staph are the most resistant of the non-endospore forming bacteria. Surface dwellers.
|
|
|
What is the most common cause of nosocomial infections?
|
staph. Watch out, you may get MRSA!
|
|
|
Staph vs. Strep: capsule formation
|
STAPH: have capsule (thicker in S. epidermis). STREP: have polysaccharide capsule, which can be a disguise if it is made of hyaluronic acid.
|
|
|
Name 3 primary species of staphylococcus.
|
S. aureus (primary pathogen). S. epidermis (opportunistic infections) S. saprophyticus (UTI in women)
|
|
|
CoNS, acronym
|
Coagulase Negative Staphylococci, ex. staph epidermis
|
|
|
What structural feature allows Staph to adhere to skin and mucous membranes?
|
fibronectin receptors
|
|
|
S. aureus: general categories of virulence factors (1-3)
|
1 surface proteins (adhesins, fibronectin), 2 invasins, 3 surface factors
|
|
|
invasins: ex (2), what each one does
|
kinase (lyses fibrin clots), hyaluronidase (lyses intracellular cement)
|
|
|
Protein A: fxn in virulence
|
Binds to the Fc part of an antibody to prevent clearance. "Grabs the bull by the horns(/tail)". This acts as a disguise because the antibodies are pointed outward.
|
|
|
Name the pore-forming toxins of S. aureus (3) and what they lyse
|
1 alpha toxin (lyse cells), 2 hemolysins (lyse erithrocytes), 3 leukotoxin
|
|
|
Name the exotoxins of S. aureus (3)
|
1 TSST, 2 ET, 3 SE. 1 toxic shock syndrome toxin, 2 epidermoliytic toxin, 3 staphylococcal enterotoxins. Shock, blisters, diarrhea.
|
|
|
Name the antibiotic resistance factors of S. aureus (2)
|
1 beta lactamase, 2 penicillin binding protein 2a
|
|
|
S. aureus: Who carries it? Where? How is it transmitted? Usual source of infections?
|
Carried by 10% of adults. Anterior nares and skin. Transmited by fomites. Autoinfections > infections from others.
|
|
|
S. aureus: general categories of diseases (3)
|
1 pyogenic infections, 2 systemic infections, 3 toxigenic infections
|
|
|
Give examples of each of the following: 1 pyogenic infections, 2 systemic infections, 3 toxigenic infections
|
1 folliculitis, 2 pneumonia, 3 toxic shock syndrome, food poisoning.
|
|
|
Give the overarching category:
- Acute endocarditis - Carbuncles - Empyema - Folliculitis - Food poisoning - Furuncles (Boils) - Impetigo - Osteomyelitis - Pneumonia - Scalded skin syndrome - Septic arthritis - Septicemia - Toxic shock syndrome - Wound Infections |
PYOGENIC INFECTIONS
- Folliculitis - Furuncles (Boils) - Carbuncles - Impetigo - Wound Infections SYSTEMIC INFECTIONS - Pneumonia - Septicemia - Empyema - Septic arthritis - Osteomyelitis - Acute endocarditis TOXIGENIC INFECTIONS - Toxic shock syndrome - Food poisoning - Scalded skin syndrome |
|
|
CLINICAL APPLICATION: What is the differential for an AIDS patient who develops a nosocomial infection?
|
Most likely to be S. aureus, but S. epidermis is also common in immunocompromised pt's.
|
|
|
S. epidermis: typical infection
|
infect catheters, shunts, and artificial heart valves
|
|
|
Major disease associated with S. epidermis?
|
endocarditis of artificial valves.
|
|
|
Akira: How are MRSA developing vancomycin resistance?
|
Getting plasmids by F pili exchange with enterococcus (Group D strep)
|
|
|
MRSA, acronym
|
methicillin-resistant Staph. aureus
|
|
|
CA-MRSA, acronym
|
community acquired MRSA; people who haven't been in a hospital, tend to be more virulent
|
|
|
go over study guides, last 2 pages
|
xxx
|
