Is an intracellular bacteria, which includes mycobacteria, Listeria, Legionella, Brucella, Coxiella and Rickettsia

F. tularensis is a potential BIOTERRORIST agent

F.tularensis subsp tularensis (type A) is one of the most infectious pathogen known in human medicine.
The infective dose in humans is extremely low: 25 bacteria in an aerosol.

Taxonomy
Family: Francisellaceae
F. tularensis subsp tularensis (type A) → virulent
F. tularensis subsp holartica (type B) → less virulent
F. tularensis subsp mediasiatica → moderate virulence
F. tularensis subsp novicida → low virulence

F. philomiraghia

Tularemia is a bacterial zoonotic disease of the northern hemisphere.
F.tularensis is highly virulent for humans and a range of animals such as rodents, hares and rabbits. It is transmitted to humans by arthropod bites, contact with infected animals, ingestion of contaminated water or food and inhalation infected aerosols.

There is no human to human transmission.

Clinical significance
F. tularensis subsp tularensis, can cause serious cinical manifestation and significant mortality if untreated. High fever is accompanied by progressive weakness, malaise, anorexia and loss of weight. Respiratory symptoms, including a dry cough, a sore throat and substernal pain may occur whether or not the disease is acquired by inhalation. Gastrointestinal symptoms such as nausea, vomiting and diarrhoea.