BACS Flashcards
<p>Staphylococcus</p>
<p>Characteristics: Gram+ cocci, catalase+</p>
<p>Staphylococcus aureus</p>
<p>O2 can be used</p>
<p>catalase</p>
<p>Reduces the potential of phagocytes to kill</p>
<p>coagulase</p>
<p>The tissue-invasive potential of staphylococcal infections is directly
proportional to coagulase production (S.aureus; not in other Staph. species).
• coagulase binds prothrombin: fibrinogen is cleaved anti-phagocytic fibrin coating</p>
<p>clumping factor</p>
<p>fibrinogen-binding protein: cell surface proteins that bind to foreign
materials (like sutures) and to extracellular matrix.</p>
<p>protein a</p>
<p>Anti-phagocytic, competes with neutrophils for Fc portion of opsonizing IgGs
(on cell surface of S.aureus but not on other staphylococcal strains)</p>
<p>staphylokinase</p>
<p>converts plasminogen to plasmin, increasing invasion by digesting
fibrin clots and cleaves C3b and IgG to inhibit phagocytosis</p>
<p>Hemolysins</p>
<p>α-, β-, γ-, and δ-toxins are all hemolysins: lyse erythrocytes (lab phenomenon)</p>
<p>Empyema:</p>
<p>Empyema: Collection of pus in a naturallyexisting anatomical cavity (e.g. lungs)</p>
<p>pyogenic infections</p>
<p>pus-forming (massive amounts of neutrophils and other leukocytes are
lysed by bacterial factors (e.g. leukocidin) and release their lysosomal
contents in attempting phagocytic killing of the staphylococci).</p>
<p>pyogenic infections</p>
<p>folliculitis furuncles carbuncles (systemic) bacteremia fever</p>
Superantigens
Overides T cell specificity.
Enterotoxins
Heat Stable. Cooking doesn’t work!
Toxic Shock Syndrome
Productions of cytokines=inflammation. Mass Activation of t-cells. Heat Stable
Exfoliative toxin
Heat stable: Heat Liable Plasmid
