Mechanisms of Mycobacterial Transmission: How does Mycobacterium Tuberculosis enter and Escape from the Human Host

In 1882, while lecturing on his discovery of the cause of tuberculosis, Robert Koch said "If the importance of a disease for mankind is measured by the number of fatalities it causes, then tuberculosis must be considered much more important than those most feared infectious diseases, plague, cholera and the like."Although Koch's identification of Mycobacterium tuberculosis (Mtb) as the cause of tuberculosis heralded many future discoveries and treatments, Mtb remains responsible for 1.5 million deaths annually.Therefore, more research is needed on all stages of Mtb infection.This commentary provides a framework for understanding two central questions in Mtb biology at the extremes of the infectious life cycle: how does Mtb enter the body and how does it escape?