Antibiotic:A drug used to treat细菌l infections. Antibiotics have no effect onviralinfections. Originally, an抗生素was asubstanceproduced 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.
In1926, Alexander Fleming discoveredpenicillin, a substance produced byfungithat appeared able to inhibit细菌lgrowth. 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, istetracycline, a broad-spectrum agent effective against a wide variety of细菌includingHemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia psittaci,Chlamydia trachomatis, Neisseria gonorrhoea, and many others. The first drug of the tetracyclinefamily, chlortetracycline, was introduced in 1948.
