Bacteria Fimbriae 菌毛 Host cell 荚膜 Host cell Virus Spikes 刺突 Host cell Bacterium Bacterium Hooks or 0钩、丝状 ost cell 体等 心 Mechanisms of adhesion by pathogens(see table 13. 6 for specific examples).(a)Fimbriae(F), minute bristlelike appendages. (b) Adherent extracellular capsules( C) made of 2021/10/18 Jime or other sticky substances. (o Viral envelope spikes(S) ( d Specialized cell hooks(H)or filaments(F)
20 菌毛 荚膜 钩、丝状 体等 刺突 2021/10/18
Intestinal tissue E coll Bacteria Skin Adhesin (ligand Microbe cel surface Receptor 1 um 10m (a) Surface molecules on a pathogen, called (b)Selective attachment of a adhesins or ligands, bind specifically to (c) Bacteria adhering to the pathogenic strain of E. coli to the skin of a salamander complementary surface receptors on intestinal tissue of a rabbit Figure 15.1 Adherence 很多吸附素是糖蛋白或脂蛋白 Most adhesins are glycoproteins or lipoproteins 病原物表面的糖蛋白/脂蛋白(配体/粘素分子) 与宿主细胞表面受体结合,选择性吸附 2021/10/18 21
21 很多吸附素是糖蛋白或脂蛋白 2021/10/18 病原物表面的糖蛋白/脂蛋白（配体/粘素分子） 与宿主细胞表面受体结合，选择性吸附
间(2)繁殖与扩散 局部繁殖、积累毒力后继续侵入机体内部 透明质酸酶、 链球菌 链激酶:水解纤维蛋白凝块,扩散 通过水解性酶类,使组织疏松、通透性增加,有利于病原菌扩散。 2021/10/18 22
（2）繁殖与扩散： 通过水解性酶类，使组织疏松、通透性增加，有利于病原菌扩散。 透明质酸酶、 链激酶：水解纤维蛋白凝块，扩散 链球菌 局部繁殖、积累毒力后继续侵入机体内部 22 2021/10/18
Cell cement Epithelial Exoenzymes cell Bacteria 产生胞外酶,松散 ooo:○ 胞间连接,扩散 Bacteria Toxins Exotoxins Epithelial cells 产生毒素,扩散到靶细胞 Nucleus Figure 13.12 The function of exoenzymes, toxins, and phagocyte blockers in invasiveness.(a) Exoenzymes Bacteria produce extracellular enzymes that dissolve extracellular barriers and penetrate through or between cells to underlying tissues. (b) Toxins(primarily 2021/10/18 exotoxins) secreted by bacteria diffuse to target cells, which are 23 poisoned and disrupted. (o Blocked(top) or incomplete(bottom)
23 2021/10/18 产生毒素，扩散到靶细胞 产生胞外酶，松散 胞间连接，扩散
间(3)对宿主防御机能的抵抗或逃避:r 吞噬阻断: 细菌的荚膜和微荚膜具有抗吞噬 和体液杀菌物质的能力; 例如肺炎球菌的荚膜。 致病性葡萄球菌产生的血浆凝固 酶有抗吞噬作用; 或有些菌分泌一些活性物质如溶 Incomplete 12 血素,抑制白细胞的趋化作用;meme enzymes, toxins, and phagocyte blockers in invasiveness.(a) Exoenzymes. B acteria produce extracellular enzymes that dissolve extracellular barriers and penetrate througl or between cells to underlying tissues. (b) Toxins(primarily 不完全吞噬: exotoxins) secreted by bacteria diffuse to target cells, which are poisoned and disrupted.( Blocked (top) or incomplete(bottom) phagocytosis. Phagocytosis is ineffective for several reason 被吞噬细胞吞噬,但仍能在吞噬时 protective coating that makes them but the 细胞内繁殖; microbes can still multiply 2021/10/18 25
（3）对宿主防御机能的抵抗或逃避： 吞噬阻断： 细菌的荚膜和微荚膜具有抗吞噬 和体液杀菌物质的能力； 例如肺炎球菌的荚膜。 致病性葡萄球菌产生的血浆凝固 酶有抗吞噬作用； 或有些菌分泌一些活性物质如溶 血素，抑制白细胞的趋化作用； 不完全吞噬： 被吞噬细胞吞噬，但仍能在吞噬 细胞内繁殖； 25 2021/10/18