+−⟲ History of Medical Microbiology Early Foundations 1670s ─ Leeuwenhoek observes microorganisms 1796 ─ Jenner develops smallpox vaccination 1840s ─ Semmelweis promotes handwashing 1860s ─ Pasteur supports germ theory 1867 ─ Lister introduces antiseptic surgery 1876 ─ Koch links Bacillus anthracis to anthrax Modern Medical Microbiology 1882 ─ Koch identifies Mycobacterium tuberculosis 1884 ─ Gram staining is introduced 1928 ─ Fleming discovers penicillin 1940s ─ Penicillin enters clinical use Late 20th century ─ PCR and molecular diagnostics transform microbiology 21st century ─ WGS, microbiome science, AI diagnostics, and AMR surveillance