Bacterial diseases are illnesses caused by bacteria, which are microscopic organisms that can cause a range of symptoms. Anthrax is a bacterial disease caused by the bacterium Bacillus anthracis, which can cause skin lesions, fever, and even death. TETANUS is a bacterial disease caused by the bacterium Clostridium tetani, which can cause muscle spasms and difficulty breathing. Diphtheria is a bacterial disease caused by the bacterium Corynebacterium diphtheriae, which can cause sore throat, fever, and even heart failure. Typhus is a bacterial disease caused by the bacterium Rickettsia prowazekii, which can cause fever, headache, and rash.