Antibiotics

An antibiotic is a substance derived from living organisms, usually bacteria or molds. That kills microorganisms or inhibits their growth. Some antibiotics also interfere with life processes in higher organisms, but the term usually applies only to substances that act against microorganisms. Synthetic drugs also used to treat bacterial, fungal, or other parasitic infections may be called antibiotics, but strictly speaking the term is reserved for substances derived from living agents. The more general term might be antibacterial or antimicrobials.

History of Antibiotics

The use of moldy and fermented substances from drug and soybean curd to treat wounds and superficial swellings is described in the earliest medical records form China, Egypt, and Mesopotamia and dates back to at least 1500 BC. For more than 3,000 years, moderately effective methods for treating superficial infections were known, but ignorance of the causes of infectious disease precluded understanding of antibiotics.

In 1874, William Roberts (1830-99) of Manchester, England, noted that the growth of fungi was often antagonistic to that of bacteria, and vice versa. He specifically observed that a mold, Penicillium glaucum, was immune to bacterial infection. Shortly thereafter Louis Pasteur and Jules Francois Joubert (1834-1910) noted that anthrax bacilli failed to grow if cultures became contaminated with airborne molds, and they suggested that this observation might have significant therapeutic implications. For about half a century, however, research on infectious diseases centered on immune serums, vaccines, and the use of chemical agents.

In 1928, Alexander Fleming noticed that growth of the pus-producing bacterium, Staphilococcus aureus, had diffused from the mold, and named if penicillin. The small, impure amounts he initially extracted lacked potency, yielding disappointing results to early attempted to treat human infections with penicillin.

In the following years a number of researcher worked to purity penicillin and produce it in large quantities, efforts that grained urgently with the outbreak of World War II. Batches of partially purified penicillin became available for military use in 1943 but were so scarce that patients urine was collected and the excreted penicillin recrystalized to be used again.

At the same time, effort were under way to isolate other antibiotics. By 1944, Selman A. Waksman and his colleagues had isolated streptomycin and proved its effectiveness against the tubercle bacillus. By 1960 hundreds of antibiotics had been discovered, and many were eventually marketed.