Francisella tularensis

Francisella tularensis is a facultative intracellular bacterium that causes an acute zoonotic disease known as tularemia, which is also referred to as rabbit fever, deerfly fever, or lemming fever. F. tularensis is a species that belongs to a large group of intracellular bacteria that includes the mycobacteria, Listeria, Legionella, Brucella, Coxiella, and Rickettsia . F. tularensis subsp . tularensis is one of the most infectious pathogens to humans. An infectious dose of as few as 10 organisms can cause an acute infection. The bulk of data on immune responses to F. tularensis infection has been generated using mammalian animal models of infection and by studying responses in humans following vaccination. The laboratory diagnosis of tularemia is based on recovery of the causative agent or detection of specific antigen or DNA in a clinical specimen or recognition of a serological response to F. tularensis in serum.