<unk>  is a pathogenic species of Gram-negative coccobacillus, an aerobic bacterium. It is nonspore-forming, nonmotile, and the causative agent of tularemia, the pneumonic form of which is often lethal without treatment. It is a fastidious, facultative intracellular bacterium, which requires cysteine for growth. Due to its low infectious dose, ease of spread by aerosol, and high virulence,<unk>  is classified as a Tier 1 Select Agent by the U.S. government, along with other potential agents of bioterrorism such as Yersinia pestis, Bacillus anthracis, and Ebola virus. When found in nature,<unk>  can survive for several weeks at low temperatures in animal carcasses, soil, and water. In the laboratory,<unk>  appears as small rods (0.2 by 0.2 µm), and is grown best at 35–37 °C.
Francisella tularensis
Yersinia pestis
Kingella kingae
Bacillus anthracis
Edwardsiella 
Salmonella enterica subsp. enterica
Listeria monocytogenes
Vibrio vulnificus