Ernest Duchesne

Ernest Duchesne (30 May 1874 – 12 April 1912) was a French physician who noted that certain molds kill bacteria. He made this discovery 32 years before Alexander Fleming discovered the antibiotic properties of penicillin, a substance derived from those molds, but his research went unnoticed.

Duchesne entered l'Ecole du Service de Santé Militaire de Lyon (the Military Health Service School of Lyons) in 1894. Duchesne's thesis, "Contribution à l’étude de la concurrence vitale chez les micro-organismes: antagonisme entre les moisissures et les microbes" (Contribution to the study of vital competition in micro-organisms: antagonism between molds and microbes), that he submitted in 1897 to get his doctorate degree, was the first study to consider the therapeutic capabilities of molds resulting from their anti-microbial activity.

In his landmark thesis, Duchesne proposed that bacteria and molds engage in a perpetual battle for survival. In one experiment, he treated cultures of Penicillium glaucum with media containing either bacteria that cause typhoid fever (Salmonella enterica subsp. enterica, formerly: Bacillus typhosus (Eberth)) or Escherichia coli (formerly: Bacterium coli communis) ; the Penicillium succumbed to the bacteria. Nevertheless, he wondered whether the Penicillium might have weakened the bacteria before the mold perished. So he injected guinea pigs with media containing bacteria (either typhoid or E. coli) and media containing Penicillium glaucum. The animals survived and were rendered immune to the bacteria. He speculated that molds might release toxins, as some bacteria do. To treat diseases, he proposed using media in which either bacteria or molds had been cultured. Duchesne concluded that:

V. Il semble, d'autre part, résulter de quelques-unes de nos expériences, malheureusement trop peu nombreuses et qu'il importera de répéter à nouveau et de contrôler, que certaines moisissures (Penicillum glaucum), inoculées à un animal en même temps que des cultures très virulentes de quelques microbes pathogènes (B. coli et B. typhosus d'Eberth), sont capables d'atténuer dans de très notables proportions la virulence de ces cultures bactériennes.

Translation: V. It seems, on the other hand, to follow from some of our experiments — unfortunately too few and which it will be important to repeat anew and to check — that certain molds (Penicillum glaucum), inoculated into an animal at the same time as very virulent cultures of some pathogenic microbes (E. coli and typhoid), are capable of reducing to a very considerable degree the virulence of these bacterial cultures.

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