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CHAPTER 1: The History of Microbiology
Pathways of Discovery in Microbiology
1.6 The Historical Roots of Microbiology 1.7 The conflict of Spontaneous Generation 1.8 Pasteur and the Defeat of Spontaneous Generation 1.9 Koch, Infectious Disease, and Pure Culture Microbiology 1.10 The Rise of Microbial Diversity 1.11 The Modern Era of Microbiology 1.6 The Historical Roots of Microbiology
Antony van Leeuwenhoek (1632-1723) -first person to observe and describe micro-organisms accurately Ferdinand Cohn (1828–1898) -founded the field of bacterial classification and discovered bacterial endospores
1.7 The Conflict over Spontaneous Generation
spontaneous generation/abiogenesis theory -living organisms can develop from nonliving or decomposing matter Francesco Redi (1626-1697) -disproved spontaneous generation for large animals -showed that maggots on decaying meat came from fly eggs
1.8 But could spontaneous generation be true for microorganisms?
John Needham (1713-1781) -his experiment: mutton b results: broth became cloudy and contained microorganisms Lazzaro Spallanzani (1729-1799) -his experiment: b results: no growth of microorganisms
Louis Pasteur (1822-1895) -his experiments placed nutrient solution in flasks created flasks with long, curved necks boiled the solutions left flasks exposed to air
results: no growth of microorganisms (aseptic)
Final blow to theory of spontaneous generation
John Tyndall (1820-1893) -demonstrated that dust carries microorganisms -showed that if dust was absent, nutrient broths remained sterile, even if directly exposed to air -also provided evidence for the existence of exceptionally heat-resistant forms of bacteria
1.9 The Role of Microorganisms in Disease
Was not immediately obvious Establishing connection depended on development of techniques for studying microbes Once established, led to study of host defenses - immunology
Recognition of the Relationship between Microorganisms and Disease
Agostini Bassi (1773-1856) -showed that a disease of silkworms was caused by a fungus M. J. Berkeley (ca. 1845) -demonstrated that the Great Potato Blight of Ireland was caused by a fungus
Koch’s postulates
The microorganism must be present in every case of the disease but absent from healthy individuals. The suspected microorganism must be isolated and grown in a pure culture. The same disease must result when the isolated microorganism is inoculated into a healthy host. The same microorganism must be isolated again from the diseased host.
1.10 The Development of Techniques for Studying Microbial Pathogens
Koch’s work led to discovery or development of: o Agar o Petri dish o Nutrient broth and nutrient agar o Methods for isolating microorganisms Charles Chamberland (1851-1908) o developed porcelain bacterial filter o used to isolate first viruses studied
Immunological Studies
Edward Jenner (ca. 1798) o used a vaccination procedure to protect individuals from smallpox NOTE: this preceded the work establishing the role of microorganisms in disease Pasteur and Roux o discovered that incubation of cultures for long intervals between transfers caused pathogens to lose their ability to cause disease Pasteur and his coworkers o developed vaccines for chicken cholera, anthrax, and rabies Emil von Behring (1854-1917) and Shibasaburo Kitasato (1852-1931) o developed antitoxins for diphtheria and tetanus evidence for humoral immunity Elie Metchnikoff (1845-1916) o discovered bacteria-engulfing, phagocytic cells in the blood evidence for cellular immunity
Industrial Microbiology and Microbial Ecology
Louis Pasteur o demonstrated that alcohol fermentations and other fermentations were the result of microbial activity o developed the process of pasteurization to preserve wine during storage
Sergei Winogradsky (1 856 - 1953) and Martinus Beijerinck (1851-1931) o studied soil microorganisms and discovered numerous interesting metabolic processes (e.g., nitrogen fixation) o pioneered the use of enrichment cultures and selective media
1.11 The Birth of Modern Chemotherapy
Treatment with chemicals is chemotherapy. Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics. Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes. Quinine from tree bark was long used to treat malaria. 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. 1930s: Sulfonamides were synthesized. 1928: Alexander Fleming discovered the first antibiotic.
The Birth of Modern Chemotherapy
1928: Alexander Fleming discovered the first antibiotic.
