B and D B and D G, F – mutans mutans
M protein M protein
M protein M protein
fibrinogen fibrinogen
r r
r
peptidoglycan peptidoglycan
r r
r
IgG IgG
Complement Complement
IMMUNE IMMUNE
NON-IMMUNE NON-IMMUNE
Toxins Enzymes
Hemolysis
alpha
beta
gamma
Pathogenesis of S pyogenes infections.
•
affect all ages peak incidence at affect all ages peak incidence at
5-15 years of age 5-15 years of age
•
non-invasive non-invasive
–
pharyngitis pharyngitis
–
skin infection, impetigo skin infection, impetigo
•
invasive bacteremia invasive bacteremia
–
toxic shock-like syndrome toxic shock-like syndrome
–
flesh eating bacteria flesh eating bacteria
–
pyrogenic toxin pyrogenic toxin
•
Scarlet fever Scarlet fever
rash rash
erythrogenic toxin erythrogenic toxin
•
rheumatic fever rheumatic fever
inflammatory disease inflammatory disease
life threatening life threatening
chronic sequalae chronic sequalae
fever fever
Heart Heart
Joints Joints
rheumatic NOT rheumatoid arthritis rheumatic NOT rheumatoid arthritis
•
Acute glomerulonephritis Acute glomerulonephritis
immune complex disease of kidney immune complex disease of kidney
Rheumatic fever -etiology Rheumatic fever -etiology
M protein M protein
–
cross-reacts heart myosin cross-reacts heart myosin
–
autoimmunity autoimmunity
cell wall antigens cell wall antigens
–
poorly digested poorly digested
in vivo in vivo
–
persist indefinitely persist indefinitely
Post-infectious diagnosis serology Post-infectious diagnosis serology
•
antibodies to streptolysin O antibodies to streptolysin O
•
important if delayed clinical sequelae important if delayed clinical sequelae
occur occur
•
superantigen superantigen
•
T cell mitogen T cell mitogen
•
activates immune activates immune
system system
Group B streptococcus - Group B streptococcus -
identification identification
•
neonatal meningitis neonatal meningitis
•
septicemia septicemia
•
transmission transmission
–
vaginal flora vaginal flora
hemolysis hemolysis
•
hippurate hydrolysis hippurate hydrolysis
•
CAMP reaction CAMP reaction
–
increases increases
hemolysis of hemolysis of
S. aureus S. aureus
Group D streptococcus Group D streptococcus
•
Growth on bile esculin agar Growth on bile esculin agar
–
black precipitate black precipitate
•
6.5 saline 6.5 saline
•
grow grow
–
enterococci enterococci
•
no growth no growth
–
non-enterococci non-enterococci
•
distantly related to other streptococci distantly related to other streptococci
•
genus genus
Enterococcus Enterococcus
•
gut flora gut flora
–
urinary tract infection urinary tract infection
•
fecal contamination fecal contamination
–
opportunistic infections opportunistic infections
•
particularly endocarditis particularly endocarditis
•
most common most common
E. S. faecalis E. S. faecalis
•
resistant to many antibiotics resistant to many antibiotics
–
including vancomycin including vancomycin
•
terminal D-ala replaced by D-lactate terminal D-ala replaced by D-lactate
Viridans streptococci Viridans streptococci
•
diverse species diverse species
•
oral oral
•
dental caries dental caries
hemolytic and negative for other tests hemolytic and negative for other tests
•
non-groupable. non-groupable.
•
includes includes
S. mutans S. mutans
–
endocarditis endocarditis
–
tooth extraction tooth extraction