NC_002755:3110929 Mycobacterium tuberculosis CDC1551, complete genome
Host Lineage: Mycobacterium tuberculosis; Mycobacterium; Mycobacteriaceae; Actinomycetales; Actinobacteria; Bacteria
General Information: This strain, also nicknamed "Oshkosh", is a recent clinical isolate from a clothing factory worker from the Kentucky/Tennessee, USA, region. It is highly contagious, infecting approximately 80% of the patient's social contacts. However, this strain has not caused epidemics in man and is sensitive to a wide range of drugs. It is also highly virulent in a mouse lung model, producing several orders of magnitude more bacteria than the H37Rv strain when inoculated. Causative agent of tuberculosis. Like other closely related Actinomycetales, such as Nocardia and Corynebacterium, mycobacteria have unusually high genomic DNA GC content and are capable of producing mycolic acids as major components of their cell wall. This bacterium is the causative agent of tuberculosis - a chronic infectious disease with a growing incidence worldwide. It infects 1.7 billion people a year (~33% of the entire world population) and causes over 3 million deaths/year. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. This bacterium does not form a polysaccharide capsule, and is an extremely slow growing obligate aerobe. The sluggish growth rate is a result of the tough cell wall that resists the passage of nutrients into the cell and inhibits waste products to be excreted out of the cell. The specialized cell envelope of this organism resembles a modified Gram positive cell wall. It also contains complex fatty acids, such as mycolic acids, that cause the waxy appearance and impermeability of the envelope. These acids are found bound to the cell envelope, but also form cord factors when linked with a carbohydrate component to form a cord-like structure. Primary infection occurs by inhalation of the organism in droplets that are aerosolized by an infected person. The organism initially replicates in cells of the terminal airways, after which it is taken up by, and replicates in, alveolar macrophages. Macrophages distribute the organism to other areas of the lungs and the regional lymph nodes. Once a cell-mediated hypersensitivity immune response develops, replication of the organism decreases and the bacteria become restricted to developing granulomas.