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1、,Chapter 5 Pathogenicity of B and Immunity against Bacterial Infections(Infection and Immunity),1. Normal Flora and opportunistic B (fig),一.Normal flora : 1.Biological antagonism 2.Nutritional function 3.Induction of immune response 4.Growth and aging,二.Opportunistic pathogens : 1.Change of normal h
2、abit 2.Endogenous infection 3.Dysbacteriosis 三.Hospital acquired infection (nosocomial infection) 1.Cross- infection : patients,doctors 2.Endogenous : from patient himself 3.Iatrogenic : (instrument),2 Mechanisms of Bacterial pathogenicity virulence : LD50 , ID50,一.Bacterial virulence : (一) Invasive
3、ness : 1. B surface structure (1)Adhesive factors: pili and lipoteichoic acid(LTA) (2)Capsule and microcapsule: Mpro , ViAg . KAg. 2. Invasive enzyme coagulase , SK , SD ,spreading factor.,(二) Toxin 1. Exotoxins: (1)G+ produce . (2)Protein in nature (3)Specific (disease) (4)Lethal (5)Neuro , Cyto ,
4、Entero (6)A : toxic B : non-toxic , binding to cells . 0.30.4 %formaldehyde (7) Exotoxin - toxoid - immunize animal Antitoxin,2.Endotoxins G, LPS , heat stable . (1)Fever(pyrogens) (2)Leukocyte response (3)Hypotension and shock (4)DIC (5)Shwartzmans phenomenon (6)etc a.active B , T , M. b.induce TNF
5、 , IFN ,CSF ,IL-6 Endotoxin detect : Limulus test .,表6-4 外毒素与内毒素的主要区别,区别要点 外 毒 素 内 毒 素,来源 革兰阳性菌与部分革兰阴性菌 革兰阴性菌,存在部分 从活菌分泌出,少数菌崩解后释出 细胞壁组分,菌裂解后释出 化学成分 蛋白质 脂多糖 稳定性 6080,30min被破坏 160,24h才被破坏 毒性作用 强,对组织器官有选择性毒害效应, 较弱,各菌的毒性效应大致 引起特殊临床表现 相同,引起发热、白细胞增 多、微循环障碍、休克、 DIC等 抗原性 强,刺激机体产生抗毒素;甲醛液处 弱,刺激机体产生的中和抗 理脱毒形成
6、类毒素 体作用弱;甲醛液处理不 形成类毒素,二.Number of Invading B 三.Portal of Entry,3. Host Immunity against Bacterial Infections,一.Non-specific Immunity (一)Barrier Structure 1.Skin and mucous membrane (1)mechanical factors (2)chemical factors (3)biological factors 2.Blood-Brain-Barrier 3.Placental Barrier,(二) Phagocyte
7、,1. Process and Mechanisms of Phagocytosis (1)Chemotaxis and adherence (2)Ingestion (3)Intracellular killing a. Oxygen-dependent system MPO Non-MPO b. oxygen-independent system 2. Fate of B after phagocytosis (1)complete (2)incomplete: TB,(三)Anti-bacterial,Substances in serum and body fluids 1.Compl
8、ement 2.-lysin 3. Lysozyme,二.Specific Immunity Humoral Cellular 三.Immunity to extracellular bacterial infections 四. Immunity to intracellular bacterial infections(cellular immunity) 五.Immunity to exotoxins（Anti-toxins）,4. Occuring and Developing of Infections,一.Origins of infections (一)Exogenous inf
9、ection 1.Patients 2.Carriers 3.Animals : suffering from disease (Carrying B) (二)Endogenous infection,二.Ways of infection transmission,1.Respiratory tract 2.Gastrointestinal tract 3.Wound / injury 4.Contact 5.Bites by insects 6. Multiple ways,(一)No-infection (二)Inapparent infection (三)Latent infectio
10、n (四)Apparent 1.Acute infection 2.Chronic infection Infection Sites 1.Local infection 2.Systemic infection,(1)toxemia (2)bacteremia (3)septicemia (4)pyemia (5)endotoxemia (五) Carrier 四.Influence of Environment on Infection (一)Natural environment (二)Social environment,Chapter 6 Principles of Diagnosi
11、s, Prevention and Treatment for Bacterial Infections,1. Diagnosis of B,一.Specimens 1.diseases and sites; 2.aseptic 3.before using antibiotics 4.from obvious diseased sites 5.fresh , quickly send to lab 6.cold 7.labeled,二.Procedures of Diagnosis,(一) Microscopy & stains (二)Culture (三)Biochemical react
12、ion (四)Serology (五)Animal test (六)Drug sensitivity (七)etc 1.HPLC 2.PCR 3.Phage 4.Bacteriocin 5.Plasmid fingerprinting,(一)Dead Vaccines (二)Live Attenuated Vaccines (三)Toxoid (四)Polysaccharide (五)Autovaccine,4. Artificial Passive Immunization,(一)Anti-toxin (二)Anti-Bacterial Serum (三)Placental globulin , (四)Preparations for CI: TF,iRNA,IFN,IL,CTL,LAK,etc.,
