1. © 2004 Wadsworth – Thomson Learning Chapter 1 The Science of Microbiology

2. © 2004 Wadsworth – Thomson Learning The Scope of Microbiology Six subgroups –Bacteria: Prokaryotic –Archaea: Prokaryotic –Algae: Eukaryotic –Fungi: Eukaryotic –Protozoa: Eukaryotic –Viruses: Acellular

3. © 2004 Wadsworth – Thomson Learning Brief History of Microbiology 1674Leeuwenhoek: sees microorganisms 1796Jenner: vaccine for smallpox 1847Semmelweiss: cause of childbed fever 1859Pasteur: disproves spontaneous gen. 1865Lister: introduces antiseptic technique 1876Kock: pure culture on agar 1892Iwanowski: discovers viruses 1894Ehrlich: selective toxicity 1929Fleming: discovers penicillin 1977Woese: classifies archaea

4. © 2004 Wadsworth – Thomson Learning Spontaneous Generation Life is formed from inanimate objects –Francesco Redi Argued against: maggots grew only from eggs –John Needham Argued for: boiled broth, covered, saw growth –Lazzaro Spallanzani Argued against: covered broth, no growth –Counterargument Covering removes air: necessary for generation

5. © 2004 Wadsworth – Thomson Learning Spontaneous Generation Louis Pasteur –Used swan-neck flask –Boiled broth –Open to the air –No growth unless broth was washed into the curved neck

6. © 2004 Wadsworth – Thomson Learning Germ Theory of Disease Koch’s Postulates 1.Microbes present in samples of diseased animal 2.Grow organism in pure culture 3.Inject healthy animal with cultured cells 4.Animal develops same disease

7. © 2004 Wadsworth – Thomson Learning Edward Jenner and Immunity Observation: –Dairymaids who had mild cowpox infections were protected from smallpox Hypothesis –Cowpox infection provides protection against smallpox Experiment –Inoculated boy with cowpox fluid and later challenged with smallpox fluid Result –Boy did not get smallpox

8. © 2004 Wadsworth – Thomson Learning Microbiology Today Chemotherapy –Paul Erhlich Selective toxicity: successful drug activity Drug for syphilis –Synthetic drugs Sulfa drugs –Antibiotics Penicillin Immunology –Independent and fast-developing science

9. © 2004 Wadsworth – Thomson Learning Microbiology Today Virology –study of viruses Basic biology –metabolism and genetic properties similar to plants and animals –microorganisms suited for experimental investigation Genetic engineering and genomics –recombinant DNA –genomics