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.

In his landmark thesis, Duchesne proposed that bacteria and molds engage in a perpetual battle for survival.

[3] In one experiment, he treated cultures of Penicillium glaucum with media containing either bacteria that cause typhoid fever (Salmonella enterica subsp.

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.While only weakly conclusive given the number of the experimental trials, this proves Duchesne understood, concluded, and published information about the effect of the Penicillium glaucum mold as a therapeutic agent in animals.