F. tularensis subsp. tularensis is a highly infectious bacterium that causes tularemia, a disease primarily affecting animals but can also infect humans. It is a small, gram-negative rod that can survive in various environments, making it a concern for public health. The bacterium is often transmitted through contact with infected animals, bites from infected insects, or inhalation of contaminated aerosols. Tularemia symptoms can vary but often include fever, skin ulcers, and swollen lymph nodes. The disease can be severe if not treated promptly, and antibiotics are effective in managing infections. Due to its potential as a bioweapon, F. tularensis subsp. tularensis is classified as a select agent by health authorities.