Chapter 9 : Louis Pasteur and the Germ Theory of Disease

Abstract:

Louis Pasteur related certain microorganisms to certain fermentation processes and determined that if competing microorganisms entered the picture, the desired fermentation process would be "diseased." His logical thinking and, more importantly, his experiments had defined the germ theory of fermentation. Resolution of the debate over spontaneous generation of microorganisms was an essential step in the development of the germ theory of human disease. Pasteur determined the attenuation of the chicken cholera bacillus to be from the harmful effect of air, specifically oxygen, on an aging culture. Pasteurization was successfully applied to wine, beer, cider, vinegar, and, of course, milk. Pasteur conducted a very public experiment of his anthrax vaccine in May 1881, where the sheep, goat and cows that had received the vaccinations of the attenuated anthrax, all appeared healthy. The filtrate induced identical agglutination of fresh red blood cells, suggesting that a soluble toxin from anthrax bacilli was capable of producing disease. The study of rabies presented great difficulties for Pasteur and his colleagues. The impact of Pasteur's work goes beyond the germ theory of disease. Pasteur linked basic research and applications in a multidisciplinary approach, what today might be called translational research.