Streptococcus

• Gram Positive Cocci
• Ferment lactic acid
• Catalase negative
• Facultative Anaerobes
• Unable to synthesize heme

• - incomplete lysis of cells (greenish)
• S. pnemoniae
• S. sanguis

• - complete lysis
• A- S. pyogenes
• B- S. agalactiae

• - no lysis
• Enterococci (used to be grouped with streptococcus)

• Lancefield antigen is cell wall carbohydrate
• Causes a lot of different diseases

• sore throat, pharyngitis (tonsilitis)
• may cause complications:

• Rheumatic Fever
• Endocarditis
• Arthritis
• Scarlet Fever (red spots)

• When body creates antibody to M
• proteins on S. pyogenes. May also attack host cells.

• Lung exposure- pnemonia
• Ear- otitis
• Meninges- meningitis
• Skin- empatigo
• Kidney- glomerulonephritis
• Necrotitis Fisciitis- flesh eating disease

• Capsule of hyuronic acid (not recognized by body as foreign)
• Lipotechoic Acid & F Proteins- bind fibronectin
• M Protein- binds fibrinogen / calligen
• Pyogenic endotoxins- superantigens

• PCR
• Serology
• Look for beta hemolysis (A)

Penicillin or Erythromycin

Beta hemolysis (B)

• Neonatal disease- pnemonia, meningitis, septicemia
• Inhabits vagina. Women are checked during pregnancy.
• Doesn't really cause disease in healthy adults
• Associated with wound infections in diabetics

• Salic acid capsule (displayed in human cells "molecular mimicry"
• C5a peptidase
• Cell lysis enzymes

cAMP test + : Lysis of sheep RBC in combination with S. aureus

Hippurate Hydrolysis +

Penicillin & Aminoglycosides

• Don't use Lancefield to identify
• S. mutans & S. sanguis (plaque on teeth)-> produce lactic acid (cavities)
• From mouth, can get into heart -> Endocarditis
• Treat with penicillin

• Naturally transformable (pick up DNA from environment)
• Older cultures stain Gram Negative
• Grow in aerobic= Greenish (alpha)
• Grow in anaerobic= Cleaning

Arthritis, sepsis, meningitis

Pneumococcal pnemonia (from X Ray)- lobar

• -Blood tinged sputum (spit blood)
• -Usually a secondary infection to a primary viral infection that weakened lungs
• -Usually only young and old die

• 1. Transparent (from nose, throat, lung)
• 2. Opaque (Grown in lab)

C Polysaccharide on capsule- precipitates C Reactive Protein, a sign of acute inflammation

IgA Protease

Pneumolysin- Lyse cilliated cells in upper respiratory tract

• Capsule can't be stained
• Ferments
• alpha hemolytic
• Bile Solution Test
• Qwuelling Test (detect capsule)
• Optochin Susceptibility (all other Strep are optochin resistant)

• Penicillin (1/3 are resistant)
• Erythromycin, Chloramphenicol
• Polyvalent Vaccine