Streptococci Flashcards
All streptococci are included in the lancefield classification except this
Viridans group, s.pneumoniae
Increased co2 for growth
Capnophiles
What is the culture in strepto
BAP
Biochemical tests in strepto
Catalase -
Oxidase -
Produce pus, mostly beta hemolytic
Grow only at 37 degrees
Pyogenic group
Grow at 10, 45, 37 degrees
Normal flora of human intestine
Enterococcus group
Grow both at 45 and 37 degrees
Viridans group
Grow at 10 and 37 degrees
Often found in dairy products
Lactic group
Species in enterococcus
E.faecalis
Species in pyogenic
S.pyogenes, groups a, , and g streptococci
Species in lactic group
S.lactis
Species in viridans group
S.salivarius, s.mutans, s.mitis
Partial incomplete hemolysis
Alpha-hemolytic streptococci
No lysis
Gamma hemolytic streptococci
Or
Non hemolytic streptococci
Complete lysis
Beta-hemolytic streptocci
Culture in beta hemolytic streptococci
Clear area
Culture in alpha hemolytic
Green hemolysis
Antigen serogrouping
Lancefield classification
She found out the c carbohydrate can be extracted from the streptococcal cell wall
Rebecca lancefield
Mostly significant in classifying and identifying beta hemolytic streptococci
Lancefield classification
This group is not considerd part of the normal flora
Mot: cough or sneeze
Group a strepto
Bacteria considered antigens
Clostridium tetani
Bordetella pertusis
Pvf of group a streptococci
M-protein
Fever producing bacteria, flesh eating bacteria
S.pyogenes
Culturein group a streptococci
Well dedined beta hemolysis
Substance that stimulates antibody formation inside the body
Antigen
Oxygen labile, highly antigenic
Surface hemolysis on bap
Streptolysin o
Produce only by pyogenes
Streptolysin O
This test detects recent infection with s.pyogenes
Anti streptolysin O
Responsible for surface hemolysis on BAP
Oxygenstable, nonatigenic
Streptolysin s
Lowers viscosity of exudates
DNAse
This enzymes causes lysis of fibrin clots
Binds to plasminogen
Streptokinase
Formerly known as erythrogenic toxins
Degrades proteins, mediates rash in scarlet fever
Pyrogenic toxins
Exotoxins are
Endotoxins are
Gram +
Gram -
Strep throat are caused by
S.pyogenes
This infection Appears initially on the neck
Scarlet fever
Strawberry colored tongue
Scarlet fever
Scarlatina
Susceptibility test in scarlet fever
Dick’s test
Dignostic test in SF
Schultz charlton
Postive result in scarlet fever in the diagnostic test
Blanching phenomenon
Similar to cockroach bite
Cellulitis
Defined areas of redness
Erythema
Accumulation of fluid
Edema
Spreading infection of subcutaneous skin tissue
Cellulitis
Produce redness
Rashes
What are the complications of strep throat
Rheumatic fever
Bright’s disease
Inflammation of the heart, joints, and blood vessels
Rheumatic fever
Inflammatory disease of the renal glomeruli
Bright’s disease
Screening test or presumptive test
Bacitracin
Concentration in taxo A
0.04 units
+ result of taxoA
Any zone of inhibition
Helpful in identifying group A streptococci in throat cultures
Bacitracin
+ result in SXT
Resistant (group a and b streptococci)
Purpose of pyr test
Detects pyrase or pyrolidonyl arylamidase enzyme
Only beta hemolytic streptococcus that is
Pyr +
S.pyogenes
+ result in pyr test
Bright/cherry red color
Reagent used in pyr test
0.01% of cinnamaldehyde
Other pyr test + organisms
Enterococcus
Aerococcus
Gemella
Part of normal flora of the female genital tract and lower GIT
Group B streptococci
Mot of group B streptococci
Unwashed hands of mother
Species in group b streptococci
S.agalactiae
C
A
M
P
Christie, atkins, munch, petersen
Virulence factor of group b streptococci
Capsule
Reagent in camp test
Beta lysin disk
+ result of camp test
Bowtie appearance
S. Agalactiae possess this enzyme
Hippuricase
Reagents in hippurate hydrolysis test
Sodium hippurate + ninhydrin
+ result of hippurate hydrolysis test
Purple color
- result of hippurate
No color change
End product of hippurate
Sodium benzoate
Main source of streptokinase
Group c streptococci
Inner greenish
Outer clear
Alpha prime
S.mitis group
Subacute bacterial endocarditis
Dental carries
S. Mutans group
L
A
P
Leucine amino peptidase
Reagent in growth in be medium
Esculin + 1-4% bile salt
+ result in growth in be medium
Black color
6.5% nacl result
Negative
Pyr test result
Negative
Penicillin test result
Susceptible
They possess the group D antigen
S.bovis group, enterococci
Best specimen for isolation of s.bovis group
Blood culture
Formerly known as group d streptococci
Enterococci
Most common isolate in enterococci
E.faecalis
Natural inhabitants of the intestinal tracts of humans and animals
Enterococci
Normal flora of intestinal
E.faecalis
Similar properties of bovis and enterococci
Group d
+ be agar test
Viridans can also be + in BE because of this
Bovis
This is only + in LAP test
Viridans
Supports all growth of bacteria
Thioglycollate
Utilized for vaginal or rectal swabs
Carrot broth, granada agar
Color of uninoculated BE
Yellow
Designed to streptococcus agalactiae
Carrot broth or granada agar
Sign of any bacterial growth
Turbidity
Has a characteristic of sweet odor of honeysuckle or butterscotch
S.anginosus group
Reagent of catalase test
3% hydrogen peroxide
Result of catalase test
Negative (without bubble formation)
Detects acetoin production
Voges proskauer test
+ lap
Streptococcus, viridans streptococci
- lap
Aerococcus
Leuconotos
+ VP
Anginosus group
End product vp
Acetoin
Also known as diplococcus
S.pneumoniae
PVF in s.pneumoniae
Capsular polysaccharide
Complication of nose and throat infections
Otitis media
Rust tinged sputum
Lobar pneumonia
Predisposing factors of lobar pneumonia
Alcoholism
Anesthesia
Malnutrition
Young colonies
Dome shaped
Old colonies
Coin with a raised rim
Standard size of a disk
6 mm
Antimicrobial susceptibility test
Optochin susceptibility
Or
P disk test
Capsular swelling test
Neufeld quellung reaction
+ result of dicks test
Erythema