Spontaneous
generation controversy:
- 1688: Francesco
Redi (1626-1678) was an Italian physician who refuted the idea of spontaneous
generation by showing that rotting meat carefully kept from flies
will not spontaneously produce maggots.
- 1836: Theodor
Schwann (1810-1882) helped develop the cell
theory of living organisms, namely that that all living organisms
are composed of one or more cells and that the cell is the basic
functional unit of living organisms.
- 1861: Louis
Pasteur's (1822-1895) famous experiments with swan-necked flasks
finally proved that microorganisms do not arise by spontaneous
generation.
This eventually led to:
Proof that microbes cause disease:
- 1546: Hieronymus
Fracastorius (Girolamo Fracastoro) wrote "On Contagion"
("De contagione et contagiosis morbis et curatione"), the
the first known discussion of the phenomenon of contagious infection.
- 1835 Agostino
Bassi de Lodi showed that a disease affecting silkworms was caused
by a fungus - the first microorganism to be recognized as a contagious
agent of animal disease.
- 1847: Ignaz
Semmelweiss (1818-1865), a Hungarian physician who decided that
doctors in Vienna hospitals were spreading childbed fever while
delivering babies. He started forcing doctors under his supervision to
wash their hands before touching patients.
- 1857: Louis
Pasteur proposed the "germ theory" of disease.
- 1867: Joseph
Lister (1827-1912) introduced antiseptics in surgery. By spraying
carbolic acid on surgical instruments, wounds and dressings, he
reduced surgical mortality due to bacterial infection considerably.
- 1876: Robert
Koch (1843-1910). German bacteriologist was the first to cultivate
anthrax bacteria outside the body using blood serum at body
temperature. Building on pasteur's "germ theory", he
subsequently published "Koch's postulates"
(1884), the critical test for the involvement of a microorganism in a
disease:
- The agent must be present in every case
of the disease.
- The agent must be isolated and cultured
in vitro.
- The disease must be reproduced when a
pure culture of the agent is inoculated into a susceptible host.
- The agent must be recoverable from the
experimentally-infected host.
This eventually led to:
- Development of pure culture techniques
- Stains, agar, culture media, petri
dishes
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