Mycobacterium tuberculosis

  Mycobacterium tuberculosis is the causative agent of tuberculosis, spreads worldwide as one of the most successful obligate bacterial pathogen and is still continues to kill million of people every year. Human acts as the only reservoir of this bacteria. They are highly aerobic bacteria and easily transmitted through coughing , sneezing and speaking around the person who is infected with M.tuberculosis.

Image: M.tuberculosis colonies. Source: CDC/ Dr. George Kubica

 

Epithelial cell are the dominant cell type in the lungs. M.tuberculosis target alveolar macrophage in the lower airways to establish infection[1]. This means that epithelial cell are the first point for the M.tuberculosis to be contacted in the human host. Once the host develop the M.tuberculosis then it is very difficult to view them under compound microscope. Extensive chemical research have shown M.tuberculosis consisting of three component. Out of them the outer layer is composed of mycolic acid which provide mycobacteria with remarkable impermeability to external service. This make it hard to view the with gram staining as they’ll appear both gram positive and gram negative[2].

….To be continued in next week.

 

 

Reference

1. Reuschl, A. et al, 2017. “Innate activation of human primary epithelial cells broadens the host response to M. bacterium in the airways. PLOS Pathogens 13(9).
2. Martinez A, Torello S, Kolter R, 1999. Sliding motility in mycobacteria. Journal of bacteriology 181(23):731-8. [PubMed]