THE HISTORY OF MICROBIOLOGY

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THE HISTORY OF MICROBIOLOGY

• Although microorganisms have been in existence
  (first living organisms on Earth), the history of
  microbiology is only a few hundred years old

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Types of Microscopes used in the study of microbes

• Light microscopes
• Simple
• Compound uses two (or more) glass lenses, total
  magnification power found by multiplying lens
  magnification powers
• Ocular X objective
• Maximum power
• Stain necessary to visualize organisms kills them
• Types of compound light microscopes include

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• Types of compound light microscopes include
• Bright field
• Phase contrast
• Dark field
• Fluorescent
• Electron microscopes- uses electromagnets, thin
  sections of dead specimen (100,000 X
  magnification)
• T.E.M.- used to see details of cell organelles
  and virus particles
• S.E.M.- used to see surface of specimens (3D)

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Scientific contributions to Microbiology

• Robert Hooke (1665)- able to see cells using a
  compound microscope
• Antoni van Leeuwenhook (Period of study
  1673-1723) saw animalcules which have since been
  identified as bacteria and protozoa
• Redi (1668) challenged the accepted theory of
  spontaneous generation
• Edward Jenner- first vaccination by using
  cowpox material scratched into an 8 year old
  volunteers arm to prevent infection by smallpox
  (boy became mildly ill with cowpox but never
  developed either smallpox or cowpox again)
  Pasteur eventually gave the process the name
  vaccination from the Latin word vacca meaning
  cow in honor of Jenners work (immunity)

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• Pasteur FATHER OF MICROBIOLOGY resolved the issue
  of spontaneous generation(1861), developed the
  basis of aseptic technique, uncovered the process
  of fermentation and developed the process of
  pasteurization (killing bacteria using heat)

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Germ theory of disease-microorganisms responsible
for disease

• Ignaz Semmelweis- 1840s demonstrated that doctors
  who did not disinfect their hands transmitted
  puerperal or childbirth fever to their
  obstetrical patients
• Joseph Lister- used phenol (carbolic acid) to
  treat surgical wounds reducing the incidence
  infections and death
• Robert Koch- (1876) proved that bacteria cause
  disease when he discovered the Bacillus anthracis
  in the blood of cattle who died of anthrax (did
  this by injecting cultures into healthy cattle
  Established Kochs Postulates

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Kochs Postulates

• The same pathogen must be present in each and
  every case of the disease
• The pathogen must be isolated from the diseased
  host and grown in pure culture
• The pathogen is inoculated into a healthy
  susceptible host and that host must develop that
  same disease
• The pathogen must be isolated from the inoculated
  animal and identified as the same organism
• Some microorganisms cannot grow on artificial
  media which has necessitated some modifications
  of Kochs postulates

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Other advances made by Koch et al

• Developed simple staining techniques to visualize
  bacteria
• Took first photographs of diseased tissue
• Used steam to sterilize growth media
• First to use agar to solidify bacteria growth
  media
• Proposed the use of platinum wire to transfer
  bacteria aseptically
• Began the use of Petri dishes to grow cultures of
  microorganisms

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Other contributors

• Florence Nightingale- 1850s introduced
  cleanliness and other aseptic techniques to the
  practice of nursing and began nursing education
• John Snow mid1800s began modern day infection
  control and epidemiology (studied cholera in
  London)
• Paul Ehrlich- (1910) development of chemotherapy
  by salvarsan (arsenic derivative) to treat
  syphilis
• Alexander Fleming (1928) accidentally discovered
  penicillin ( bacteria culture plates were
  contaminated by mold growth which inhibited the
  growth of the bacteria)

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Modern day microbiology

• Epidemiology
• Genetic engineering
• Immunology
• Vaccines
• Bioremediation
• Industrial application
• Bioterrorism possibilities

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