Virulence factors of s aureus Structural components Enzymes Toxins
Virulence factors of S. aureus Structural components Enzymes Toxins
Y Structural components: inhibit phagocytosis by PMN elicit production of IL-l mediate attachment and opsonic antibody b monocytes, be a chemo Capsule or polysaccharide attractant for PMn: have slime layer endotoxin-like activity Peptidoglycan layer activate complement Polysaccharide bind to fibronectin and ( teichoic acid) mediate attachment Protein A bind to f fis cytople inhibit phagocytosis complement membrane Cytoplasm Clumping responsible for adherence facto of the organisms te fibrinogen and fibrin forming clumps, induce an ImmunogenIc response
inhibit phagocytosis by PMN; mediate attachment elicit production of IL-1 and opsonic antibody by monocytes; be a chemoattractant for PMN; have endotoxin-like activity; activate complement bind to fibronectin and mediate attachment bind to Fc portion of IgG; inhibit phagocytosis; anti complement responsible for adherence of the organisms to fibrinogen and fibrin – forming clumps; induce an immunogenic response Structural components:
Staphylococcus PHAGOCYTE Protein A (SPA) Fc receptor dd↓ SPA BACTERIUM antibody opsonization Y Binds to Fc portion of igG(gG1, 2, 4) Y Inhibits phagocytosis Anti complement
SPA IgG Fc receptor PHAGOCYTE BACTERIUM Staphylococcus Protein A (SPA) Binds to Fc portion of IgG(IgG1,2,4); Inhibits phagocytosis; Anti complement antibody opsonization
Coagglutination S aureus Antibody-sensitized Coagglutination Staphylococci
S.aureus Antibody-sensitized Staphylococci Coagglutination Coagglutination
√ Enzymes Y Catalase - degrades hydrogen peroxide; differentiates the staphylococci from streptococci v Coagulase and Clumping factor- coagulates plasma and blood; produced by 97% of human isolates, anti phagocytosis; invasive potential Uronidase Y Staphylokinase v Proteinases pases B-lactamase swelling
Catalase – degrades hydrogen peroxide; differentiates the staphylococci from streptococci Coagulase and Clumping factor– coagulates plasma and blood; produced by 97% of human isolates; antiphagocytosis; invasive potential Uronidase Staphylokinase Proteinases lipases β-lactamase swelling Enzymes: