医学微生物学英文版教学课件：第12章mycobacterium

1、1Chapter 14Mycobacterium2Section 1. Mycobacterium tuberculosis(tubercle bacillus) 3 Discovery of M.tuberculosisGerman bacteriologist Robert Kochfound & testified on march 24th, 1882Robert Koch42007 TB anywhere is TB everywhere “结核流行广泛，控制从我做起”2008 I am stopping TB，You can stop TB join us “控制结核，人人有责”“

2、控制结核，人人有责-关注农民工，共享健康 2010 遏制结核，健康和谐 2011遏制结核，共享健康 2012 Stop TB in my lifetime Call for a world free of TB “你我共同参与，消除结核危害”2013 “你我共同参与，消除结核危害”世界防治结核病日 3月24日 5Mortality g Highg Moderateg None or low6鲁迅先生（1881-1936）林徽因（1904-1955）71.morphology & staining*thin,straight or slightly curved rods *acid-fast

3、stain-red*thick, complex, lipid-rich cell wall*non-motile, non-spore, non-capsuleI biological properties892.culture*obligate aerobe*special nutrient requirement yolk, glycerol(甘油), malachite green(孔雀绿), potato*slow growth generation time - 18h primary isolation 34 weeks*colony - “cauliflower（菜花 ）”*p

4、ellicle on surface of liquid media101112EUGONIC GROWTH 14 DAYS133.resistance*resistant to dry (in dried sputum, 6-8 months) acid - 3% HCl, 6% H2SO4 alkali - 4% NaOH dyes*sensitive to moist heat disinfectant - alcohol drug - rifampin, isoniazid, etc UV144.Variation 1). virulent variation - BCG (Bacil

5、lus Calmette-Guerin)The vaccine contains a strain of live, attenuated M.bovis. BCG vaccine is effective in preventing the appearance of tuberculosis, especially in children. 152). drug resistance variation(multidrug resistant TB, MDR TB ) a worldwide problem16II Pathogenicity & Immunity M.tuberculos

6、is produces no invasive enzymes, no exotoxin and does not contain endotoxin in its cell wall. 17The pathogenicity is likely caused by 1. bacteria reproduction within tissue cells resulting in inflammation2. toxicity of bacterial components and metabolic products3. immunopathological effects 181.Path

7、ogenic factor (1)Lipid (closely related to virulence) cord factor (索状因子) phosphatide(磷脂) wax D (蜡质D) sulfatides (硫酸脑苷脂) 19cord factor1). binds to mitochondrial membrane, cause functional damage to respiration and oxidative phosphorylation 2). inhibits migration of leukocyte 3). causes chronic granul

8、omatosis 20Phosphatide Stimulate monocytes proliferation- form tubercle Inhibit proteinase- form caseous necrosis(干酪样坏死)wax D acts as an adjuvant resulting in delayed type hypersensitivity (DTH)21sulfatides inhibits the fusion of phagosome and lysosome in the phagocytes22(2) Protein tuberculin(结核菌素)

9、 combined with wax D delayed type hypersensitivity (DTH) 23 Transmission Usually a respiratory infection, others as wound, food can cause infection-lung, intestine, kidney, skin, lymph node, bone, joint primary infection 1) lung infection post-primary tuberculosis 2) Out lung infection 2. pathogenes

10、is24Pulmonary tuberculosis: （1）primary tuberculosis organismrespiratory tractpulmonary alveolarlesionshilar lymph nodes swellingfibrosisnatural cure （2）post-primary tuberculosis organisminfection again inflammation necrosistubercle fibrosis/caseous necrosistypical intracellular parasites2526Who is a

11、t riskprimary tuberculosis: children post-primary tuberculosis: adult27sites of involvement primary tuberculosis: lung disseminated sites 1. gastrointestinal 2. lymph nodes 3. bones 4. kidneys 5. central nervous system-brain, spine 2829301.the main anti-infectious immunity - CMI (intracellular paras

12、ites) defective cellular immunity predisposes to severe tuberculosis. the antibody is not protective2.infection immunity3.CMI and DTH (delayed type hypersensitivity)immunity31It is a test for delayed type hypersensitivity. Positive reaction, reddening and thickening (5mm) at the site of PPD injectio

13、n after 2-3 days, indicates cellular immunity to tubercle bacilli.Tuberculin Skin Test32*OT (old tuberculin) *PPD (purified protein derivative) 33 PPD injection 48-72h induration, erthyema 1.principle: delayed type hypersensitivity 2.result and interpretation3435 “-” - 5mm: # no TB infection; # earl

14、y stage of infection; # the level of cellular immunity is low: tumor, AIDS, use immunosuppressive agent 36“+” - 5mm 15mm: hypersensitive to M. tuberculosis, immunity “+”- 15mm: active TB373. application* detect immunity effect of BCG inoculation *epidemiological investigation of TB infectionhelp to diagnosis TBInspect the CMI level of the patient38 1. specimen: sputum, urine etc. * direct smear - acid-fast stain * treatment with NaOH and concentration by centrifugation- acid-fast stain III microbiologic examination392. culture - specimen concentration sp