Benjamin Minge Duggar (1872–1956), Lloyd Conover (b. 1922)
In 1948, Benjamin Minge Duggar, a seventy-six-year-old retired professor of botany working as a consultant for Lederle Laboratories, made the discovery that immortalized him. He found chlortetracycline (Aureomycin), which was produced by a golden-colored bacterium of the Streptomycetes genus. Chlortetracycline was active in combating a very wide range of bacteria, plus a variety of microbes that had failed to be curbed by any of the existing drugs. Two years later, a team of scientists at Pfizer found oxytetracycline (Terramycin). In 1952, Lloyd Conover, also at Pfizer, synthesized tetracycline, the first antibiotic made in the lab from a natural drug. Within three years, tetracycline, the most illustrious and financially successful of the triumvirate, became the most widely prescribed broad-spectrum antibiotic in the United States.
The 1950s witnessed highly contentious patent-infringement suits involving rival manufacturers of tetracycline with dueling trade names that included Achromycin, Tetracyn, Panmycin, and Sumycin. These suits remained unresolved until 1982. In addition, the Federal Trade Commission raised illegal price-fixing charges against five companies, alleging that they had colluded to keep the price of tetracycline artificially high.
Over the years, the tetracyclines were widely popular but indiscriminately prescribed for minor disorders. This led to the development of resistance by bacteria that had readily succumbed to the effects of tetracyclines in the past. Now, decades later, these drugs have lost their initial luster and are recommended for treating only a very limited number of microbial diseases.
The tetracycline antibiotics gain access to tissues and fluids throughout the body, including the bones and teeth, where they are stored. If taken between the ages of two months and five years, when permanent teeth are being calcified, they can cause brown discoloration of teeth. Similarly, when the tetracyclines are given to pregnant women, particularly during the second and third trimesters of pregnancy, discoloration of their offspring’s teeth may occur.
SEE ALSO Streptomycin (1944), Chloramphenicol (1949), Ampicillin (1961).
The test in this Petri dish is to determine the sensitivity of a bacterial culture to tetracycline and three other antibiotics. The large dark circle in the upper left shows a powerful antibiotic response to bacterial growth. The circle in the lower left shows a weak response. These kinds of results are used when selecting the most effective antibiotic to treat a bacterial infection.