"An antibiotic for all seasons, it's used for a dozen reasons... there is no proxy, for our antibiotic doxy."
James McCallum, from the poem "Doxycycline"
The world existed for a long time without antibiotics, but as soon as they were discovered, the race was on to find more. Penicillin and streptomycin had both been isolated from some form of fungus, and the search continued for products that came from naturally occurring bacteria.
Research groups looked everywhere but one of the more promising avenues of investigation began to emerge from groups studying certain fungi that lived in soil—organisms known as actinomycetes. Lederle Laboratories found the now forgotten antibiotic aureomycin in dirt samples. Pfizer soon followed suit with the equally obscure antibiotic terramycin. Both aureomycin and terramycin functioned as broad-spectrum antibiotics, covering a range of both gram- positive and gram-negative bacteria. This sparked a great deal of interest in figuring out how they worked.
Lloyd Conover (b. 1923) made a breakthrough while studying the actinomycete-derived antibiotics. He figured out that they both shared a common structure that would prove to be the active component. The new chemical, dubbed tetracycline, represented the first time a naturally occurring substance was modified to produce an enhanced drug. The resulting chemical and its derivatives doxycycline and minocycline, are still used today to treat a variety of ailments.
