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HISTORY OF MICROBIOLOGY Chapter 1, pp 1-16

With the development of microbiology, came 4 important concepts:
1) discovery of microorganisms - refutes spontaneous generation
2) pure culture concept
3) germ theory of disease
4) role in chemical transformations

I. Discovery (Table 1-1, p4)
- 1665 Robert Hooke - observed cells in sections of cork
~ (1680s) Leeuwenhoek - “animalcules” observed in rain water, other sources (Fig page 1)
Spontaneous Generation = life from non-life, disproving this belief:
~ 1670 Redi - demonstrated larva present on meat was from eggs
~ 1765 Spallanzani and others used sealed flasks and treated air to prevent microbial growth
however, others such as Needham claimed a vitalistic force in air was necessary for
spontaneous generation to occur.
- 1860’s Louis Pasteur - “Father of Microbiology” used swan necked flasks (Fig 1-2, p2)
to disprove spontaneous generation. Also, observed that heat could kill these microbes. This led to the development of Pasteurization. (also see Tyndall)

II. Pure Culture Concept
pure culture = 1 type of organism grown in culture, once this was accomplished,
microbes could be studied individually.


III. Germ Theory of Disease - proved role of microorganisms in causing disease.
A) - 1870’s Robert Koch - demonstrated 6 different infections in mice caused by 6 different bacteria; demonstrated anthrax was caused by bacteria

1884 - 4 postulates (Koch’s) (page 464)
1) organism present in diseases cases, absent in healthy animals
2) can be isolated from diseased animal and grown in pure culture
3) disease can be reproduced by inoculation of healthy animal with cultured organism
4) organism can be re-isolated from experimentally infected animal and returned to culture (pure)

B) Koch’s work and others led to the “Golden Age of Microbiology”
1) causes of many diseases were determined
2) improved culture methods
3) improved staining techniques

C) Lister in 1860s, developed aseptic surgical techniques, used carbolic acid
(phenol) to treat dressings.


IV. Cell Theory

V. Role of Microorganisms in Chemical Transformations
A) 1837, demonstrated that Yeast generated alcohol

glucose + H2O ---> ethanol + CO2

B) 1857 - 1876, Pasteur demonstrated such fermentations were microbial processes
C) 1897 Buchner discovered enzymes

VI. Areas developed from Microbiology
Development of microbiology led to the following areas:
1) Immunology
2) Chemotherapy
3) Virology
4) Molecular Biology

A) Immunology
1) 1796 Jenner - immunity to smallpox conferred by inoculation with cowpox
2) 1881 Pasteur - used “attenuated” virus for immunization against rabies
3) 1884 Metchnikoff - observed phagocytosis = cellular theory of immunity
4) 1890 Emil von Behring - immunity in cell free portions of blood = humoral theory

B) Chemotherapy
1) 1908 Ehrlich - treatment for syphilis (salvarsan = arsenic derivative)
2) 1929 Fleming - penicillin
3) 1944 Waksman - streptomycin
4) 1950’s - many antibiotics discovered

C) Virology
1) 1892 Iwanowski - showed an agent passing through a filter caused a disease in plants
2) 1931 - cultivation of viruses in chick embryos
3) 1949 - cultivation in cell cultures

D) Molecular Biology
1) Monoclonal antibodies - 1975 Kohler and Milstein fused myeloma and antibody producing cells = hybridoma which generates monoclonal antibodies
2) Genetic engineering - 1973 Chakrabarty transferred genes from one organism to another



MICROBIOLOGY TODAY
Leading causes of death in the U.S.:

VII. Major microbial groups (see Tables 1-2, p10; 1-3, p11; 1-4, p13; Fig 1-12, p12)

VIII. Sizes of microorganisms (see Fig 1-13, p13)


IX. Classification
Nomenclature = binomial system of genus and species
Escherichia coli

variations in members of same species = strains
Escherichia coli K12
E. coli ML
E. coli O157:H7

X. Fields of microbiology
A) Medical and Clinical
B) Veterinary
C) Public Health
D) Immunology
E) Virology
F) Molecular biology, genetics, biotechnology
G) Microbial Physiology and biochemistry/geochemical
H) Aquatic
I) Food

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