††††An antibiotic is a substance which is able to destroy invading bacteria whilst leaving its host unharmed. The term antibiotic was coined in 1941.
Penicillin, the first antibiotic drug, was discovered by Alexander Fleming in 1928. Early antibiotics were entirely natural substances, produced by living fungi and bacteria. By 1955, however, chemical modifications were introduced.
Different types of antibiotic work in different ways. Some, like penicillin, work by killing the bacteria. Others, such as tetracyclines, prevent new bacteria from forming. In the latter case, the bacteria already present are usually killed by the body's natural defences. Today there are concerns that overuse of antibiotics has encouraged the development of bacteria resistant to this type of treatment. Although most bacteria are unlikely to be resistant to all forms of antibiotic, it is possible that in the future new "super bacteria" could cause extensive problems.
