It is set in stone that Mycobacterium tuberculosis is a facultative intracellular bacterial
parasite. This axiom drives our knowledge of the host response, the way we design vaccines
against the organism by generating protective T cells, and to a lesser extent, the way we try
to target anti-microbial drugs. The purpose of this article is to commit total heresy. I believe
that M. tuberculosis can equally well be regarded as an extracellular pathogen and may in
fact spend a large percentage of its human lung “life-cycle” in this environment. It is of course …