A. History of Bacteriology
1. Anton van
Leeuwenhoek
• First drawings of bacteria
• First observations of bacteria at the microscopic level
• Able to describe presence of different microorganisms such as protozoans
• Father of Bacteriology and Protozoology
• First microscope had a magnification of x30 + x266
2. Christiaan
Huygens
• First descriptions free living protozoans
3. Robert Hooke
(1667)
• First descriptions of filamentous microscopic fungi (mold)
• Remember: Two forms of fungi include yeast and mold
• Molds grow at room temperature
4. Pietro Antonio
Micheli
• described 900 species of molds
5. Cicero and
Fracastorius
• It was believed before that fevers might be caused by minute animals
(contagium vivum)
6. Louis Pasteur
• Discredited the theory of Spontaneous Generation:
• The idea that Living things come from non-living things.
• Jan Baptista Van Helmont believed that flies and mice arise from old
piece of rug and meat/wheat kernels in an open container, left for 3
weeks
• When air is filtered through cotton wool, large numbers of microorganisms are
held back.
• Performed an experiment by boiling meat broth in flasks to sterilize
them, and one left open, the other closed.
• Found out that microorganisms can be airborne
7. John Tyndall
• existence of heat-stable forms of certain bacteria
• Believed that some organisms cannot be killed by only heating them
continuously; some are heat-stable
• Related to organisms with virulence factor
• Characteristic of a bacteria for survival; in relation to temperature and
environment
• Example: some bacteria develop spore when exposed to high
temperature to protect them.
• Discovered the process of Tyndallization
• removal of which involved the process of repeated heating and rest
• Considered as a measure of microbial control
8. To progress
○ Improvement in microscopes
• Example: Brightfield with OIO magnification is 10 (lens) x 100 = x1000
• Now, electron microscopes can reach up to million magnification
○ Development of methods for culturing microorganisms
• Culturing is about propagation of bacteria in vitro (external)
• Most infection-causing microorganisms (pathogen) are considered
normal flora/normal microbiota (requires body temperature and carbon)
• Using synthetic media; culture medium
9. Robert Hooke
(end of 16th
century)
• Microscope with 3-500x
• Recognized cellular structures due to greater magnification
10. Ferdinand
Cohn (1849)
• Staining of histological specimens
• Discovered the first stain for histological specimen (tissues):
• Vegetable dyes: carmine and hematoxylin
