Glossary of strep, enterococ

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gram stain of strep/entero generi (two genera)
NOT nice and round;
broth cultures give chains in gram stain.

a little messier than staphs
What are the growth characteristics of Streptococcus and Enterococcus?
Fastidious, facultative anaerobes (like Staphs, only fastidious)

Grows on BA in increased CO2
What are the characteristic antigens on Streptococcus species?
C carbohydrates - use lancefield typing

M protein - protects from phagocytosis
3 Ways Streps and Enterococcus are differentiated:
1. Hemolysis

2. Presumptive tests - biochemical

3. Definitive tests - imunological
gamma isolates of strep/enter
S. viridans

Strep group D Non-Enterococcus
two tests on gamma isolates
-bile esculin (neg shows saprophyticus)

-6.5% NaCl (pos shows enterococ, neg shows strep D non-enter)
What test is an alternate to 6.5% NaCl?
Where is S. viridans normal flora?
What causes Bacterial Endocarditis?
Subacute caused by:
-Staphylococcus epidermidis
-Streptococcus viridans

Acute caused by:
Staphylococcus aureus
What is used to treat Streptococcus viridans infections?
what is intrinsiclaly resistant to penicillin
enterococcus; not due to beta lactamase, it just is
4 diseases caused by enterococci
wound infections
treat with __ if an enterococcus is

-blactamase neg
-b-lactamase pos
neg = ampicillin

pos = vancomycin

(2 genes that encode it)
vancomycin resistant enteroc


how do Van A and Van B mediate resistnc?
A - plasmid-mediated; worse cuz it can jump to other bugs

B - chromosomally-mediated; stays within the cell line.
know about Strep D non-enteroc:
rare in humans, can cause endocarditis, treat w/ penicillin
You have an alpha-hemolytic gram positive cocci; what tests do you inoculate?
1. bile esculin
2. salt

3. optichin
principle of optichin test
disc contains ethylhydrocupreine HCl; if the bug is susceptible, zone of more or equal to 14 mm will show. resistant if less. (S. pneumonia and S. viridans are resistant)
alpha hemolytic, bile esculin negative, optichin positive/negative: que es?
s. pneumoniae is pos
S. viridans is neg
what tests is alternate to optichin?
bile solubility
micro/macro morpho of strep pneumoniae
1. lancet shaped GPDC

2. if autolyzed, flat, mucoidy, checkers

What makes Strep pneumoniae pathogenic?
-M-protein which makes it resist phagocytosis
lobar pneumonia pathology: what happens?
bug enters, inflammatory response is WBC, fluid and RBC; can't breathe across alveoli - lobar consolidation
high fever; shaking chills; sharp pleural pain; rusty sputum; what is it?
lobar pneumoniae caused by strep pneum.
why does s. pneumon cause red sputum?
rbc's in it
3 diseases caused by strep pneumoniae:
lobar pneumonia
otitis media
to treat s. pneumonia:
=penicillin or ciprofloxacin
vancomycin if necess
normal flora site of strep pneumoniae
oral cavity, small numbers
enterococcus normal flora site
how do you prevent streptococcal pneumoniae?
via vaccine;

pneumovax for over 2 years old,
What test identifies S. viridans?

2 species and commonly caused disease (Kristine)
Optichin neg (diff from s. pneumoniae)

tests done on beta strep
bile esculin
bacitracin or pyr
CAMP or hipp hydrolysis
bile esculin of beta strep diffs
positive is rare - nothing
negative do tests on
test to do on bile esc negative organisms:
CAMP - identifies beta strep B

Bacitracin - identifies beta strep A
does beta strep A resist or suscept to bacitracin?
it's positive, so it resists it
principle of CAMP test
beta strep B produce compound that in conjunction with S. Aureus' hemolysin will cause complete hemolysis and an arrow shape
alternate test for CAMP
Beta strep Antigen aka
how to test for it
C- carbohydrate

flourescent antibody or latex agglutination
strep group A aka and its normal flora site:
aka strep pyogenes; normally in oral cavity in 15% of population
s. pyogenes produces what 6 pathogenic products:
streptokinase - digest fibrin, spread
streptodornase - break down dna
hylauronidase - break down connect tiss
erythrogenic toxin - red scarlet fever
hemolysins - break down RBC
M protein - resist phagocytosis
two hemolysins produced by s. pyogenes, strep group A:
Streptolysin S, O
ASO TEST tests for O by antibody action

O is O2 labile

S is O2 stabile
diseases caused by strep pyogenes (A)
strep throat
scarlet fever
erysipelas and cellulitis
wound infections
pyogenic STrep A infections
post-strep diseases
what are pyogenic strep A infections?
necrotizing fasciitis
toxic shoc-LIKE SYNDROME
what are post streptococcal diseases?
acute glomerulonephritis
rheumatic fever
how do you treat strep pyogenes (group a)
with peniccilin
strep group B is aka

normal floral site?
strep agalactiae

normally in oral cavity in low numbers, maybe vagina but abnormal and must protect fetus before delivery
what type of infection does s. agalactiae cause
neonatal infections:
-respiratory distress syndrome
direct specimen test for S. agalactiae
group b Antigen test
how do you treat group B strep? (s. agalactiae)
with penicillin
beta hemolytic strep other than A B or D
normal flora, COULD cause phjaryngitis (streplike) but normal usually, susceptible to peniccilin
what are 5 OTHER cat neg GPC?
=leukonostoc - rare, unusual to cause infection, only in compromised; INTRINSIC RESISTANCE TO VANCOMYCIN!

What are all streptococcus organisms treated with, and what is NOT treated with it?
Enterococcus is intrinsically resistant, but everything else is susceptible to penicillin.

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