The penicillin revolution and the role of the forgotten pioneer Vincenzo Tiberio (1869-1915): discovery, development and legacy

Penicillin’s discovery is widely attributed to Alexander Fleming (1881-1955) Professor of Bacteriology at St. Mary’s Hospital in London in 1928, who observed the antibacterial effects of Penicillium mold. Fleming found that his “mold juice” was capable of killing a wide range of harmful bacteria, such as streptococcus, meningococcus and the diphtheria bacillus. He then set his assistants, Stuart Craddock and Frederick Ridley, the challenging mission of isolating pure penicillin from the mold juice. It shown to be very unstable, and they were only able to prepare solutions of crude material to work with. Fleming published his findings in the British Journal of Experimental Pathology in June 1929, with only a passing reference to penicillin’s potential therapeutic benefits. However, over 30 years earlier, Italian physician Vincenzo Tiberio (1869-1915) had conducted controlled studies on the bactericidal effects of mold extracts, publishing results that went largely unnoticed by the scientific community.This article runs through a work plan timeline and significance of early antimicrobial discoveries, tracing the overlooked work of Tiberio, Fleming’s breakthrough, the biochemical properties of penicillin, and the wartime efforts that enabled its mass production. The story of penicillin is not only one of scientific innovation but also of missed recognition, collaboration, and the complex interplay of chance and preparedness.