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
What is the major growth char for Streptococcus?
|
Spherical, gram-positive cocci growing in CHAINS.
|
|
What are the four major human pathogens in the genus Streptococcus?
|
1) S. pyogenes
2) S. agalactica 3) S. pneumonia 4) Viridans streptococci |
|
What's the difference between Lancefield Groups and Hemolysis classification?
|
Lancefield is determined by surface antigens, hemolysis is determined by blood agar growth chars.
|
|
What bacterial factor causes beta-hemolysis?
|
Streptolysins S or O
|
|
What bacterial factor causes alpha-hemolysis?
|
Peroxides
|
|
What important biochemical characteristic is used to ID Streptococcus?
|
Catalase Test: all are catalase NEGATIVE
|
|
Name the common term, hemolytics, and Lancfied for:
S. pyogenes |
GAS: Group A Beta-Hemo Lancefield A
|
|
Name the common term, hemolytics, and Lancfied for:
S. agalactiae |
GBS: Group B Beta,Gamma Lancefield B
|
|
Name the common term, hemolytics, and Lancfied for:
S. pneumoniae |
Pneumococcus Alpha Lancefield Not Detectable
|
|
What are the major post-infection sequelae of GAS infection?
|
Rheumatic Fever, Glomerulonephritis
|
|
What's the major pathogenic trick of GAS/S. pyogenes?
|
Disrupts opsonization and evades phagocytosis
|
|
What surface protein aids GAS/S. pyogenes in colonization/adhesion?
|
M Protein
|
|
How does GAS/S. pyogenes avoid opsonization?
|
C5A Peptidase
|
|
What host antibody/serology test is used to detect GAS infection?
|
ASO Titer, or anti-Streptolysin O AB test
|
|
Does GAS have an exotoxin?
|
Yes - Streptococcal pyrogenic exotoxin (SPE), linked to scarlet fever, TSS, and nec fasc
|
|
What's the transmission method for GAS pharyngitis?
|
Person-to-person via respiratory droplets or nasal secretions.
|
|
Describe the symptoms of GAS Pharyngitis
|
Abrupt onset, malaise, fever and HA. Incubation time approx. 2-4 days.
|
|
Physical findings of GAS Pharyngitis?
|
1) Hyperemic tonsilitis
2) tonsilar exudates 3) Oropharyngial petechiae |
|
What major symptom is NOT FOUND in GAS Pharyngitis?
|
Cough
|
|
Gold standard for GAS Pharyngitis Dx?
|
Throat Culture. (Clinical rapid strep against Lancefield antigen possible for empiric therapy.)
|
|
What subcutaneous GAS infection involves the cheeks and forehead?
|
Erysipelas
|
|
What fast-moving GAS infection follows fascial planes?
|
Necrotizing fasciitis
|
|
What streptococcal pathogen has major impact on newborns?
|
S. agalactiae - vertical transmission resulting in septicemia and meningitis
|
|
What Genus Species is associated with GBS?
|
Steptococcus agalactiae
|
|
What are the adult clinical manifestations of GBS/S. agalactiae
|
Chorioamnionitis, endometritis, UTI
|
|
What's the definitive dx for neonatal GBS?
|
CSF and blood culture, followed by latex agglutination test.
|
|
I say alpha-hemolytic gram positive diplococci, you say...
|
Streptococcus pneumoniae
|
|
What's the major pathology found in Strep. pneumo infections?
|
Immunogenic damage caused by host response to infection.
|
|
What's the most common cause of septic meningitis in children less than two years of age?
|
Streptococcus pneumoniae
|
|
How does Streptococcus pneumonia take hold in the lung?
|
Impaired defenses, such as smoking, chronic illness
|
|
What's one of the most common bacterial isolates from acute otitis media?
|
Streptococcus pneumonia (along with non-typable Haemophilus influenza)
|
|
How is Strep. pneumo detected in the laboratory?
|
Culture - alpha hemolytic, optochin sensitive
|
|
Can Streptococcal pneumonia be prevented?
|
Conjugated Purified Polysaccaride Vaccine available
|
|
What bacterial/infective complication can result from dental work?
|
Endocarditis caused by Streptococcus mutans
|
|
What "Group D Strep" coccus is now classified on it's own?
|
Enterococcus
|
|
Enterococcus Characteristics?
|
Gram positive
Catalase negative Gamma hemolytic Diplococci in short chains NORMAL FLORA in Intestine and Female GU |
|
What normal gut flora bacteria causes highly resistant nosocomial/iatrogenic infections?
|
Enterococcus ssp.
|
|
What streptococcal bacteria is associated with colon cancer?
|
Streptococcus bovis
|