双语-08-球菌.pptVIP

Chapter 8Coccus球菌 Categories of cocci Staphylococcus（葡萄球菌属） Streptococcus（链球菌属） Neisseria（奈瑟菌属） Section 1 Staphylococcus葡萄球菌属 Biological characterization Morphology: Gram-positive spherical cells arranged in grape-like clusters. Lack spore and flagellum Culture characteristics: Colonies: round, smooth, raised, glistening Pigments: fat soluble; golden yellow (pathogenic), white or lemon Blood agar plate: β-hemolysis （溶血）(pathogenic) Biochemical reactions Catalase（触酶）test: + Antigens SPA ★ Capsular polysaccharide Other polysaccharides Classification Staphylococcus aureus（金黄色葡萄球菌） Staphylococcus epidermidis（表皮葡萄球菌） Staphylococcus saprophyticus（腐生葡萄球菌） Resistance: relatively strong, resistant to many antibiotics ★ SPA 葡萄球菌A蛋白 Staphylococcal Protein A Definition: A cell wall component of many S. aureus strains that binds to the Fc portion of IgG molecules except IgG3. In vitro, SPA has become an important reagent in immunology and diagnostic laboratory technology. In vivo, SPA can effectively diminish opsonization. Pathogenesis and symptomatology Pathogenic substances ★ Enzymes Toxins Surface structure proteins Adhesin（黏附素） Capsule（荚膜） Peptidoglycan（肽聚糖） SPA Enzymes Coagulase（凝固酶） Other enzymes Fibrinolysin Fibrinolysin（纤维蛋白溶酶） Heat-stable nuclease（耐热核酸酶） Hyaluronidase（透明质酸酶） Lipase（脂酶） Coagulase（凝固酶） An enzyme-like protein produced by S. aureus that clots oxalated or citrated plasma. Its production is considered as invasive pathogenic potential. Two types: Free coagulase（游离凝固酶） Bound coagulase（结合凝固酶） 凝固酶的作用 保护作用：抗吞噬，抗杀菌物质 感染病灶的病理特性：局限化、脓汁粘稠和形成血栓 具有免疫原性 Toxins Staphylolysin （葡萄球菌溶素） Leukocidin（杀白细胞素） Enterotoxin（肠毒素） Exfoliative toxin（表皮剥脱毒素） TSST-1（毒性休克综合征毒素-1） Staphylolysin（葡萄球菌溶素） α,β,γ,δ-toxins Cytotoxin. It is a potent hemolysin (溶血素). Acts on a broad spectrum of eukaryotic cell membranes. (RBCs, WBCs, platelets, hepatocytes, etc.) Leukocidin（杀白细胞素） Cytotoxin. Damage the cell membranes of neutrophils and macrophages. Inhibit phagocytosis and