Vin·cent \vaⁿ-saⁿ\ Jean Hyacinthe (1862–1950), French bacteriologist. Vincent was a researcher and later director at various French laboratories engaged in bacteriological and epidemiological research. In 1896 he described a fusiform bacillus and a spirochete which in association are the cause of hospital gangrene. These bacteria are called Vincent's organisms. Two years later he demonstrated that these two microorganisms are present in necrotizing ulcerative infections of the gums, tonsils, and throat; two forms of these infections are now known as Vincent's angina and acute necrotizing ulcerative gingivitis or Vincent's infection.