Bacterias Flashcards
STAPHYLOCOCCUS AUREUS
“The golden staff of Moses”
STAPHYLOCOCCUS AUREUS
“The golden staff of Moses”
What does Staphylococcus Aureus literally mean?
Staphylococcus (grape like)
Aureus (gold in color)
Gram type of Staphylococcus Aureus?
Gram Positive Cocci
What tests can be used to determine Staphylococcus Aureus?
Catalase (+)
Coagulase (+)
Beta Hemolytic (+)
Mannitol (+)
What is the main virulence factor on Staphylococcus Aureus and how does it work?
Protein A; Main virulence factor on staph aureus.
Protein A is a component of S. Aureus cell wall and
it can bind to the FC region of antibodies and this will prevent compliment from occurring.
Preventing opsonization and phagocytosis.
Where does Staphylococcus Aureus mainly colonize?
S. Aureus will colonize the nares
What are the 10 possible diseases that can be caused with Staphylococcus Aureus?
- Gastroenteritis
- Acute bacterial endocarditis
- Abscesses and mastitis (Humps with red cloth - Really large erythematous abscesses)
- Toxic shock syndrome
- Impetigo
- Scalded Skin Syndrome (SSS)
- Pneumonia
- Surgical infections
- Osteomyelitis
- Septic Arthritis
What causes the coughing in Staphylococcus Aureus infection?
Coughing - Pneumonia
Patchy infiltrate on x-ray
What is the shape of the capsule of the virus that will infect after a Staphylococcus Aureus infection?
Icosahedron shaped capsule of the virus that will infect after a S. Aureus infection.
What is Staphylococcus Aureus is the most common cause of in adults? (Hint: 2 diseases)
Septic Arthritis and Osteomyelitis.
In Staphylococcus Aureus acute endocarditis, what is the most common cause of it and where does it affect it in the heart?
IV drug use
Tricuspid valve Endocarditis
What mediates Scalded Skin Syndrome in a Staphylococcus Aureus infection?
Scalded skin syndrome mediated by a protease
What causes Toxic Shock Syndrome in a Staphylococcus Aureus infection?
Toxic Shock Syndrome, commonly caused by leaving a bandage in or a tampon which causes nonspecific binding of MHC II to T cell receptors causing over-reaction and Cytokine storm.
What does a Catalase test measure?
Turns hydrogen peroxide –> water
What does a Coagulase test measure?
Fibrinogen –> fibrin
What does a Beta Hemolytic test measure?
When looking at petri dish with B-hemolysis it looks like a glowing halo of light.
Beta-hemolysin breaks down the red blood cells and hemoglobin completely. This leaves a clear zone around the bacterial growth.
What does a Mannitol test measure?
If it CAN ferment manitol it will turn the agar to yellow.
If it CAN’T ferment manitol the agar will stay pink.
What is the treatment of choice for Staphylococcus aureus infection?
Nafcillin/oxacillin are drugs of choice because of widespread antibiotic resistance.
“Naf for Staph”
What is the treatment for methicillin-resistant Staphylococcus aureus (MRSA)?
Vancomycin
What is the treatment for vancomycin-resistant Staphylococcus aureus (VRSA) or vancomycin- intermediate S. aureus (VISA)?
quinupristin/dalfopristin
STAPHYLOCOCCUS EPIDERMIDIS AND STAPHYLOCOCCUS SAPROPHYTICUS
“Beauty and the Plumber”
STAPHYLOCOCCUS EPIDERMIDIS AND STAPHYLOCOCCUS SAPROPHYTICUS
“Beauty and the Plumber”
Staphylococcus epidermidis and Staphylococcus saprophyticus are what type of gram?
Gram (+)
Staphylococcus epidermidis and Staphylococcus saprophyticus are Catalase + or -?
Catalase Positive
Staphylococcus epidermidis and Staphylococcus saprophyticus are Urease Positive. What does that mean?
Urea –> ammonia