文档详情

结核分枝杆菌(英文PPT).pdf

发布:2021-06-19约3.98千字共13页下载文档
文本预览下载声明
Mycobacterium tuberculosis (tubercle bacillus) Biological properties 1. Morphology staining *thin,straight or slightly curved rods *acid-fast stain--red *thick, complex, lipid-rich cell wall *non-motile, non-spore 2. Culture *obligate aerobe *special nutrient requirement yolk, glycerolmalachite green, potato *slow growth generation time -- 18h primary isolation – 3~4 weeks *colony -- “cauliflower” *pellicle on surface of liquid media 3.Resistance *resistant to : dry, acid, alkali *sensitive to: moist heat, UV, alcohol 4.Variation 1) virulent variation - BCG (Bacillus Calmette-Guerin) ➢ The vaccine contains a strain of live, attenuated M.bovis. ➢ Culture:yolk, glycerol(甘油), malachite green, potato ➢ 230 passages, 13years. ➢ BCG vaccine is effective in preventing the appearance of tuberculosis, especially in children. 2) drug resistance variation multidrug resistant TB (MDR TB ), a worldwide problem Pathogenicity Immunity ➢ M.tuberculosis produces no invasive enzymes, no exotoxin and does not contain endotoxin in its cell wall. ➢ The pathogenicity is likely caused by : 2. toxicity of bacterial components and metabolic products 3. immunopathological effects ➢ Pathogenic factor (1) Lipid (closely related to virulence) cord factor 1) binds to mitochondrial membrane, cause functional damage to respiration and oxidative phosphorylation 2) inhibits migration of leukocyte 3) causes chronic granulomatosis wax D acts as an adjuvant resulting in delayed type hypersensitivity (DTH) Phosphatide Stimulate monocytes proliferation form tubercle Inhibit proteinase form caseous necrosis Sulfatides inhibits the fusion of phagosome and lysosome in the phagocytes (2) Protein tuberculin combined with wax D DTH 2. pathogenesis ➢ Transmission occurs by the aerosol route but also occur through other routes. ➢ Infectio
显示全部
相似文档