Antibiotic: A drug used to treat bacterial infections. Antibiotics have no effect on viral infections. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks.
In 1926, Alexander Fleming discovered penicillin, a substance produced by fungi that appeared able to inhibit bacterial growth. In 1939, Edward Chain and Howard Florey further studied penicillin and later carried out trials of penicillin on humans (with what were deemed fatal bacterial infections). Fleming, Florey and Chain shared the Nobel Prize in 1945 for their work which ushered in the era of antibiotics.
Another antibiotic, for example, is tetracycline, a broad-spectrum agent effective against a wide variety of bacteria including Hemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia psittaci, Chlamydia trachomatis, Neisseria gonorrhoea, and many others. The first drug of the tetracycline family, chlortetracycline, was introduced in 1948.
- Antibiotic resistance
The ability of bacteria and other microorganisms to resist the effects of an antibiotic to which they were once sensitive. Antibiotic resistance is a major concern of overuse of antibiotics. Also known as drug resistance.
- Antibiotic-resistant tuberculosis
Antibiotic-resistant tuberculosis: See: Tuberculosis, antibiotic-resistant.
Antibody: An immunoglobulin, a specialized immune protein, produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production. The production of antibodies is a major function of the immune system and is carried out by a type of white […]
- Antibody cross reactivity
Antibody cross reactivity: The ability of an antibody to react with similar antigenic sites on different proteins.
- Antibody, antinuclear
Antibody, antinuclear: An unusual antibody that is directed against structures within the nucleus of the cell. Antinuclear antibodies (ANAs) are found in patients whose immune system is predisposed to cause inflammation against their own body tissues. Antibodies that are directed against one’s own tissues are referred to as autoantibodies. The propensity for the immune system […]