MICI 3119 Lecture Notes - Lecture 4: Bcg Vaccine, Mycobacterium Bovis, Cell Envelope

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Mycobacterium: aerobic and nonmotile rods, considered to be gram-positive but cannot be gram stained; instead can be stained by acid-fast stain, grow slowly (weeks) and survive within macrophages, many species are important human pathogens. M. bovis -- tuberculosis: (bcg vaccine) Acid-fast stain of mycobacterium tuberculosis in sputum: tuberculosis. Cover the smear with a piece of blotting paper and ood with carbol fuchsin (in phenol). Steam for 5 minutes by passing the slide through the ame of a gas burner. Add the acid-alcohol drop-wise slowly until the dye no longer runs off from the smear. 1) refractory to antibiotics (except rifampin & streptomycin). 2) "acid-fast" nature characteristic for presumptive identi cation in sputum and infected tissues: has adjuvant properties and may be responsible for the development of delayed type hypersensitivity (dth). Freund"s complete adjuvant is a potent adjuvant in immunization and it contains killed mycobacteria. Gram-negative cell envelope and the pores are much longer.