The Francisella genus contains Gram-negative, non-motile, strict aerobes which can cause human infection. The most clinically important species, F. tularensis, causes tularemia which is disease that humans can catch from tick bites. This highly infectious disease is carried by rodents, deer, pets, and many other animals. Humans can acquire the organism in several different ways through lesions in skin. Many times their will be an ulcer at the site of penetration. Also, inhalation of the organism occurs in roughly 10% of all cases. A sudden onset of flu like symptoms (headache, fever, chills) is observed in infected individuals. Lab identification can be made using a medium called cysteine-blood agar. The is effective because F. tularensis requires cysteine (an amino acid) for growth. Most hospital labs shouldn't process this organism, however, because it is highly contagious. The preferred antibiotic treatment for treating patients consists of streptomycin.