Front | Back |
What is the main virulence factor in Streptococcus A infection? Why is it also a weak point in the bacteria's defense?
|
M protein - it adheres to cells, is anti-phagocytotic, and antigenic - which is its weak point, because it trigger's antibody production (that is what antigenic means) in the immune system.
|
Which Strep strain is present in about 30% of vaginas as Normal Flora?
|
Strep B
|
What are some clinical characteristics of Rheumatic Fever, and what causes it?
|
"John Travolta in Rheumatic Fever". Myocarditis, arthritis, chorea (arm crazy movements), rash. It is due to Strep A antibodies cross-reacting with antigens on the heart, years after Strep A infection.
|
What are several diseases caused by Strep A?
|
Pharyngitis (Strep Throat), Scarlet Fever, Puerperal Infection (endometrium of mother in labor, dangerous to mother if infection gets into blood and travels), Acute Glomerulonephritis, Rheumatic Fever.
|
What is the difference between Streptolysin S and Streptolysin O, and what does a streptolysin do?
|
They destroy red and white blood cells. Streptolysin O (O=oxygen labile) is inactivated by oxygen and it is antigenic. Streptolysin S (S= oxygen Stabile) works in O2 environment, and it is NOT antigenic (no antibodies formed).
|
What type of diseases can Strep B cause?
|
All our neonatal (B is for Baby) - meningitis, sepsis, pneumonia.
|
What are the 3 bacterial causes for Meningitis during labor? What are the 2 bacterial causes for Meningitis later in life?
|
Neonatal Meningitis - Strep B, E. coli, Listeria. Later in Life - Neisseria meningitidis, Haemophilus influenzae.
|
An elderly person with Strep B will present with what main complaint?
|
Stiff Neck
|
Which enterococcus is susceptible to Ampicillin?
|
Enterococcus faecalis. E. faecium is resisant to Ampicillin and emerging a resistance to Vancomycin.
|
A patient who recently had a dental procedure presents with subacute endocarditis. What caused the infection?
|
Strep viridans.
|
What is a Quellung Test? What bacteria is commonly tested for with this?
|
Detects encapsulated bacterium by testing for anti-capsular antibodies. Strep pneumoniae, H. influenzae.
|
What are the 4 clinical diseases caused by Strep pneumoniae?
|
MOPS - meningitis, otitis media (kids), pneumonia, sepsis.
|
Streptococcus pyogenes - which group is this?
|
Strep A. (Streptococcus agalactiae is group B)
|
Skin rashes Impetigo, Ecthyma, Erysipelas - what bacteria ususually cause these?
|
Strep A. Erysipelas is a rash of the dermis only, often appears just of the face.
|
What does the morphology of Staphylococcus look like?
|
"Staph in clusters"
|