Streptococcacae Flashcards
Types of Streptococcacae on Basis of Hemolysis
Alpha hemolysis
Beta hemolysis
Gamma hemolysis
Alpha hemolysis and color shown
Partial hemolysis
Green color
Alpha hemolysis include which organisms
V - S. Viridans
S. Pneumonia
Beta hemolysis and color shown
Complete hemolysis
Yellow color
Beta hemolysis is further classified on basis of
Lancefield Classification (C antigen)
Lancefield Classification
20 groups (A to V) - No I and J
Group A - S. Pyogenes
Group B - S. Agalactaie
Capsule of S. Pyogenes is made up of
Hyaluronic acid - cross react with synovial joints
Virulence factor of S pyogenes associated with cell wall
C antigen
Virulence factor of S pyogenes associated with outer membrane protein
M Protein - Similar to glycoproteins (Molecular mimicry)
Enzymes and toxins released by S pyogenes
Streptokinase - causes Fibrinolysis
Hyaluronidase - break Connective tissue
DNAase A, B, C ,D - DNAse B(M/I)
Hemolysin / Streptolysin
Streptococcal Pyrogenic exotoxin (SPE)
Serum opacity factor (SOF)
Types of Streptolysin/Hemolysin
Streptolysin -O
Streptolysin -S
Effect of O2 and heat on SL-O and SL-S
SL-O - Labile
SL-S - Stable
Which is antigenic - SL-O or SL-S
SL-O
Functions of SL-O and SL-S
SL-O - lethal, Cardiotoxic, Leucocidal
SL-S - Only Leucocidal
Hemolysis in SL-O and SL-S
SL-O - Deeper
SL-S : Surface
Types of Streptococcal Pyrogenic exotoxin (SPE)
A, B and C
A and C - Bacteriophage mediated
B - Chromosomal mediated
Streptococcal Pyrogenic exotoxin is associated with which diseases
Scarlet fever
Toxic Shock syndrome
Necrotizing Fascilitis
Suppurative Clinical features of Group A Streptococcal Infection
NIPPLES
N - Necrotizing Fascilitis
I - Impetigo
P - Pneumonia
P - Pharyngitis (Pain, Tender Cervical LN, No cough)
L - Lymphadenitis
E - Erysipelas
S - Streptococcal Toxic Shock syndrome, Scarlet fever
Erysipelas
Raised well demarcated, Painful red lesion (Superficial skin)
Clinical features of Scarlet fever
SCARLET fever
S - Sore throat
C - Circumoral Pallor
A - Antecubital fossa - Pastia line
R - Rash (Sandpaper)
L - Lymphadenopathy
E - Erythrogenic toxin (SPE)
T - Tongue (Strawberry)
Fever
Non suppurative Clinical features of Group A Streptococcal
PSGN
Rheumatic heart disease
PANDAS (Pediatric autoimmune Neuropsychiatric disorder associated with Streptococcus)