1. Mycobacterium tuberculosis Characteristics
Mycobacterium tuberculosis is a non-motile, acid-fast, obligate aerobe bacterium that resists decolorization with acidified organic solvents
Considered hydrophobic due to the high lipid content in the cell wall
It is not considered gram positive nor gram negative, but instead is classified as acid-fast
M. tuberculosis is manifested more often in HIV positive patients due to a weakened immune system
High resistance to drug therapy
Contagious for several weeks after drug therapy is initiated
A. Ryan F2013
Modified by DYH

2. M. tuberculosis Virulence
M. tuberculosis does not have the classical virulence factors
Lipoamide dehydrogenase (Lpd) - helps the bacterium resist host-reactive nitrogen intermediates
Antigen 85 complex: group of secretedproteins that bind fibronectin; may help in protecting the bacterium from the immune system
Slow generation time: immune system may not readily recognize the bacterium and therefore not be able to kill it
High lipid concentration of cell wall: enables the bacterium to be resistant to many antimicrobial agents, acidic and alkaline compounds, and osmotic lysis
Cord factor: known to be toxic to humans and other mammalian cells
A. Ryan F2013
Modified by DYH