Introduction

• Germ theory states that specific microscopic organisms are the cause of specific diseases.

• Germ theory is also called the pathogenic theory of medicine.

• Germ theory led in to the development of antibiotics and hygienic practices.

• It is considered as the cornerstone of modern medicine and clinical microbiology.

• Major contributors to germ theory are:

  • Antoni van Leeuwenhoek
  • Francesco Redi
  • Rudolf Virchow
  • Louis Pasteur
  • Joseph Lister
  • Robert Koch

Terms

• Microbes, or microorganisms - minute living things that are usually unable to be viewed with the naked eye.

• Germ - refers to a rapidly growing cell.

• Spontaneous generation - the hypothesis that living organisms arise from nonliving matter. It was an important early development in the germ theory.

• Biogenesis:  living cells can arise only from preexisting cells.

• Antibiotics - chemicals produced by bacteria and fungi that inhibit or kill other microbes.

Major Concepts

Antoni van Leeuwenhoek (1673-1723)

• Microorganisms were first directly observed by Antoni van Leeuwenhoek, who is considered the father of microbiology.

Edward Jenner

• In 1796, Edward Jenner inoculated a person with cowpox virus.

Agostino Bassi (1835)

• Agostino Bassi showed a silkworm disease was caused by a fungus.

Ignaz Semmelwise (1840)

• He advocated hand washing to prevent transmission of puerperal fever from one patient to another.

Louis Pasteur

• Louis Pasteur was one of the first to link germs to disease.

• In 1861, Louis Pasteur demonstrated that microorganisms are present in the air.

• Pasteur discovered vaccines for chicken cholera. (1880), Anthrax (1881) and Rabies (1885).

• Pasteur also showed that microbes are responsible for fermentation.

Joseph Lister

• Joseph Lister is considered as inventor of antiseptic surgical techniques.

• In 1860s, Joseph Lister used a chemical disinfectant to prevent surgical wound infections.

Robert Koch

• In 1876, Robert Koch explained a bacterium causes anthrax.

• In 1882, he discovered the germ that caused tuberculosis. (TB)

• In 1883, he discovered the germ that caused cholera.

Alexander Fleming

• In 1928, Alexander Fleming discovered the first antibiotic from Penicillium fungus.

References

1. "The History of the Germ Theory". The British Medical Journal 1 (1415): 312. 1888.

2. Germ Theory in Contagion: Historical Views of Diseases and Epidemics. Harvard University Library; accessed on 8/9/2011. Available at http://ocp.hul.harvard.edu/contagion/germtheory.html