Francisella tularensis is a pathogenic species of Gram-negative bacteria.
It is causative agent of tularemia or “rabbit fever” (It is called rabbit fever because rabbits are vectors for the disease) that is contagious to humans, the pneumonic form of which is often lethal without treatment.
There are four known subspecies of Francisella tularensis . There are two strains of Francisella tularensis that are studied the most: the more virulent Type A strain (found in North America), and the less virulent Type B (subspecies holarctica , also referred to as palearctica) strain (found in Europe). Two other subspecies are the non-virulent mediasiatica, found in central Asia, and novicida, which not much is known about.
The F. tularensis is a highly contagious bacteria that can be spread from animals to humans, through vectors such as mosquitos and fleas, or from being breathed in from the air. The bacteria infects humans through skin, mucous membranes, lungs, and the gastrointestinal tract. People infected with tularemia through inhalation also develop hemorrhagic inflammation of the airways early in the disease, and it might develop into bronchopneumonia.
Ulceroglandular-the most common type of tularemia, usually caused by a insect bite. At the site there is a skin sore, which becomes an ulcer. Glands in the area of the ulcer will swell. The ulcer is accompanied by fever, chills, headaches, and fatigue.
Glandular- There is no obvious ulcer, and symptoms are fever and swollen glands.
Typhoidal- Usually caused by breathing in the bacteria, but it can also be caused by insect bite and contaminated water and food. Symptoms are fever, weight loss, fatigue, and usually pneumonia.