•Chapter 5 •Pathogenicity of B and Immunity against Bacterial Infections(Infection and Immunity)
Dec 31, 2015
• 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 habit • 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 ) Invasiveness :• 1. B surface structure• (1)Adhesive factors: pili and lipoteichoic acid(LTA) • (2)Capsule and microcapsule: M - pro , Vi -Ag . K-Ag.
• 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 ~ , Entero ~• (6)A : toxic• B : non-toxic , binding to cells .• 0.3~0.4 %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)Shwartzman’s phenomenon• (6)etc• a.active B , T , MΦ.• b.induce TNF , 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 60 ~ 80℃,30min 被破坏 160℃,2 ~ 4h 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• 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.Complement
• 2.β-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 infection
• 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 infection
• (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 Diagnosis, 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 reaction• (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 , γ ~
• ( 四 )Preparations for CI:
TF,iRNA,IFN,IL,CTL,LAK,etc.