The tularemia-causing bacterium Francisella tularensis is a facultative 
intracellular organism with a complex intracellular lifecycle that ensures its 
survival and proliferation in a variety of mammalian cell types, including 
professional phagocytes. Because this cycle is essential to Francisella 
pathogenesis and virulence, much research has focused on deciphering the 
mechanisms of its intracellular survival and replication and characterizing both 
bacterial and host determinants of the bacterium's intracellular cycle. Studies 
of various strains and host cell models have led to the consensual paradigm of 
Francisella as a cytosolic pathogen, but also to some controversy about its 
intracellular cycle. In this review, we will detail major findings that have 
advanced our knowledge of Francisella intracellular survival strategies and also 
attempt to reconcile discrepancies that exist in our molecular understanding of 
the Francisella-phagocyte interactions.