Rene Dubos

American bacteriologist 1901-1982

In 1939 Rene Dubos launched the antibiotic era by reporting the discovery of gramicidin after the first systematic search for antimicrobial agents. Fol­lowing this discovery he warned of microbial resistance to antibiotics, com­pleted innovative studies of tuberculosis, expanded investigations into the nature of disease and, ultimately, examined the question of health.

Born near Paris in 1901, Dubos studied agronomy in France and, through a chance meeting with biochemist Selman Waksman, was invited to study soil science at Rutgers University. In his Ph.D. studies, Dubos dis­covered that local soil characteristics determine which microbes decompose cellulose.

By good fortune again, Dubos joined Oswald Avery of the Rockefeller Institute (now University) who was trying to decompose the polysaccharide capsule surrounding the deadly pneumococcus bacterium. Dubos succeeded by using a soil enrichment technique to find a specific microbial enzyme.

He further discovered this enzyme was produced only if the polysaccharide capsule was the microbe’s sole food, a phenomenon now known as an in­duced enzyme. He described this as “his greatest hour in science . . . one of the most important biological laws I have ever been in contact with.”

In 1939, using the same techniques, he found Bacillus brevis, a microbe that digests and destroys other microbes. From it he extracted an antibac­terial agent he named tyrothricin that contains two polypeptides he called gramicidin and tyrocidine. Within a few months, he and organic chemist Rollin Hotchkiss described the bacterial, chemical, clinical, and pharma­ceutical properties of these antibiotics. This work stimulated two English scientists, Howard Florey and Ernst Chain, to revive the stalled research on penicillin, found accidentally in 1929 by Scottish bacteriologist Alexander Fleming.

In 1942 Dubos warned that bacterial resistance to antibiotics should be expected, saying, “In the analysis of . . . antibacterial agents . . . susceptible bacterial species often give rise with ‘training’ to variants endowed by great resistance to these agents.”

Dubos turned his interest to tuberculosis in 1944. He began a renais­sance in studying this disease by creating a culture medium to produce rapid, luxuriant, and well-dispersed growth of bacilli. He pioneered inter­national standards for the BCG vaccination against tuberculosis and de­scribed social aspects of the disease in “The White Plague” (1952). Later he investigated how environmental effects of crowding, malnutrition, pes­ticides, toxins, and stress increase susceptibility to disease.

Dubos observed that people coexist with both good and bad microbes and that disease-producing microbes reside quiescently (dormant) in the body until stress alters resistance. He restated the germ theory, saying a mi­crobe is necessary but not sufficient to cause disease. He concluded that in order to improve one’s physical and spiritual well-being, one must first un­derstand and then control one’s impact on one’s own surroundings.

When he won the Pulitzer prize in 1969 for So Human an Animal, Du- bos was thrust into the swelling environmental debate. He became well known for balancing views between those who believe that humans can im­prove on nature and those who advocate wilderness preservation. Hundreds of lectures and two dozen books evolved from medical considerations of en­vironment and health, to cultural and scientific aspects of medicine, to an ecological philosophy encompassing health of Earth. He coined many apho­risms such as “think globally, act locally” to explain complex issues.

References

Dubos, Rene. So Human an Animal. New York: Charles Scribner’s Sons, 1968.

Moberg, Carol L., and Zanvil A. Cohn. “Rene Jules Dubos.” Scientific American 264, no. 5 (1991): 66-74.