Lancefield

Hemolysin Rep. Species Characteristics Major Clinical Syndromes

Classification
Local Invasion and/or eotoxin release
Pus producing
1. Streptoccocal Pharyngitis
Anti- phagocytic & anti- immunogenic 2. Strep Skin Infections
Susceptible to Bacitracin a. Cellulitis
M protein (major virulence factor; weakest point) b. Impetigo
Pili (partly M protein covered by lipoteichoic acid) c. Necrotizing fascitis
Treatment: Penicillin & clindamycin
Group A PATHOGENIC ENZYMES 3. Scarlet Fever
(rhamnose N- S. pyogenes Streptolysin O (O2 labile; antigenic) 4. Streptococcal Toxic Shock Syndrome
acetylglucose- amine) Streptolysin S (O2 stabile; not antigenic) Delayed Antibody- Mediated Disease
Pyrogenic Exotoxin ( causes scarlet fever & streptococcal 1. Acute Rheumatic Fever
toxic shock syndrome) With prior Strep pharygitis without skin infection
Streptokinase (activates plasmin) Myocarditis to rheumatic valvular heart disease
Hyaluronidase ( splits hyaluronic acid to penetrate and infect) Prophylactic Penicillin theraphy
DNAses (degrade DNA -> produce pus) 2. Acute Glomerulonephritis
Anti-C5a peptidase (inactivates c5)
1 week after strep pharygitis with skin infection
Part of normal flora in vagina, urethral mucous membrane, Neonatal Meningitis
Group B
and lower GIT Neonatal pneumonia
(rhamnose- S. agalactitiae
Fever, vomiting, poor feeding, and irritability (NO nuchal Neonatal sepais
glucoseamine)
rigidity) Treatment: Penicillin + Ampicillin
Viridans Group S. mutans Bind to teeth and ferment sugar Dental Carries
Opportunistic
Microaerophilic
pathogens of S. intermedius Abscess in the brain or abdominal organs
low virulence Normal GIT flora
UTI
Normal Bowel Flora Biliary Tract Infection
Enterococci
Group D Grow well in 40% bile and 6.5% NaCl Bacteremia
(glycerol theicoic acid SBE
with d-alanine & UTI
S. bovis & S.
glucose) Grows in 40% bile but not in 6.5% NaCl Biliary Tract Infection
equinus
Epidemiologically associated with colon cancer Bacteremia
(nonenterococci)
SBE (Subacute Bacterial Endocarditis
C polysaccharide (not associated with Lancefield antigen Pneumonia
Gram stain: Gram (+) cocci in pairs (diplococci) Otitis Media in Children
Virulence Factor: Polysaccharide capsule Meningitis
Cell Associated Enzymes Vaccines
Autolysin: hydrolyze CM to activate Lyt A, B, C -> release Pneumovax (25 common capsular polysaccharide antigens)
S. pneumoniae pneumolysin o For asplenic, immunocompromised, and elderly patients
Pneumolysin: intracellular virulence factor loacted in the o Low immunogenicity and efficacy
cytosol -> attack CM Heptavalent Conjugate Vaccine (7 capsular polysacc. Antigens)
o Pneumolysin binds to cholesterol -> stimulates o 4, 6B, 9V, 14, 18C, 19F, 23F conjugated with nontoxic
proinflammatory cytokines -> inhibit leukocytes and diphtheria-toxin
activate complement pathway o 100% efficacy in prevention in children
Reduce cases of otitis media in children