Streptococcus

Streptococcus

Low G+C Cocci pairs/chains FA Non motile, NSF Capnophiles Catalase (-) Peroxidase Hemolysins Lancefield Groups

18 antigens Cell wall reactivity

Lancefield Groups

Membrane Ag Groups A-H, K-V

Group A Strep. pyogenes

Group B Strep. agalactiae

Group C, F, G Strep equisimilis Strep zooepidemicus Strep anguinosus

Group D E. faecalis Strep bovis Strep equines

Group K Strep salivarius

Viridans Strep mutans Strep mitis Strep sanguis

Pneumococci

Strep Virulence Factors

GAS: Strep pyogenes Location

Skin, mm Resp: pharynx

Pathogenicity Adhesins

Protein F and S (fibronectin) Lipoteichoic acid (LTA)

Immune evasion Protein M

Binds to fibrinogen Mimics CT/Muscle

antigens Capsule (hyaluronic acid)

Proteins Streptolysins (leukocidins)

Function Lyse formed

elements Beta hemolysis

Types S = O2 stable O = O2 labile

Strep pyogenes Enzymes

Streptokinase Break down clots

DNase B depolymerize

Hyaluronidase Proteases C5a peptidase

Decrease chemotaxis Toxins Exotoxins

Pyrogenic (A, B, C) Superantigens

Increase immune cytokines

Promote fever TSS like syndrome

Sepsis M1 and M3 strains

Strep pyogenes infections

Strep pyogenes diseases

Pharyngitis Scarlet Fever (rash) Skin

Pyoderma Impetigo Erysipelas Cellulitis

Strep TSS Necrotizing fasciitis Myositis Immune Mediated

Rheumatic fever Glomerulonephritis

Necrotizing Fasciitis and Meningitis

GBS: Strep agalactiae Epidemiology

GI Uritogenital

Pathogenicity Capsule Enzymes

Proteases Hemolysins

Beta hemolysis Hyaluronidase

Disease Puerperal fever Vaginitis UTI Endocarditis Osteomyelitis Newborn

Meningitis Sepsis Pneumonia

CAMP test

Group C Strep

Strep equi strangles

Strep equisimilis pharyngitis

Strep anginosus abscess

Viridans Streptococcus

Alpha hemolysis No Lancefield groups Diseases

Dental Caries Endocarditis Examples

Strep mitis Strep mutans Strep oralis Strep sanguis Strep salivarius (K)

Biofilms

Strep. pneumoniae

Strep pneumonia capsule

Strep pneumoniae

Epidemiology Mouth Upper respiratory Dz = lungs

Pathogenicity Capsule Protein A Phosphorylcholine Adhesins Proteases

Protects from IgA

pneumolysins

Strep pneumonia diseases

Group D Strep

Examples E. faecalis E. faecium S. bovis S. equines

Location: GI Tests

Gamma hemolysis Salt tolerant Bile tolerant

Pathogenicity Bacterocins Nosocomial

Enterococcus Sequella

Rapid Strep Test

Vaccination

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