MCB 3020C Lecture Notes - Lecture 31: Necrotizing Fasciitis, Streptococcal Pharyngitis, Group A Streptococcal Infection
Document Summary
Invasiveness: ability of microbe to maintain presence and in many cases spread. Hyaluronidase: catalyzes the breakdown of hyaluronic acid, which cements human cells in tissue together and allows bacterial cells to spread through tissue causing cellulitis (staph, strep, & Virulence factors (invasiveness): secreted enzymes break physical barriers. allows microbe to establish itself in host and often spread. Coagulase- this enzyme catalyzes the conversion of fibrinogen to fibrin with resultant clot formation. Present in pathogenic staphyloccus aureus. (clot prevents them being phagocytized). Fibrinolysin - this catalyzes the conversion of plasminogen to the fibrinolytic enzyme plasmin. In staphylococcus aureus, the gene for fibrinolysin is on a bacteriophage and is expressed during lysogeny. Lipase: production of excessive amounts of lipase allow bacteria to penetrate fatty tissue with the consequent formation of abscesses. Collagenase: this enzyme catalyzes the degradation of collagen, a protein found in tendons, ligaments, cartilage, nails and hair. Leukocidins: cause lysis of white blood cells; staphyloccus aureus (pyogenic: pus producing)
