week1 b

HISTORY OF MICROBIOLOGY : 

HISTORY OF MICROBIOLOGY Microbes are discussed in history because they have had an enormous effect on people and events. Outcomes of wars fought prior to WWII were decided by arms, strategy & pestilence (infectious disease). Napoleon retreated from Moscow in 1812 when his army suffered from typhus, pneumonia & dysentery. In 1813, he formed a new army of 500,000 soldiers which also became ill due to crowded, unsanitary conditions and was reduced to 170,000 (105,000 were earlier casualties but 220,000 were infected with disease). So, Napoleon’s 1815 defeat in Waterloo was due, in large part, to microbial infection.

Historical Roots of Microbiology : 

Robert Koch germ theory demonstrates that specific microorganisms cause specific disease (Koch’s postulates) Isolated pathogens by developing techniques that furthered the advancement of microbiology Historical Roots of Microbiology Microscopy 1664: Robert Hooke 1684 – A. V. Leeuwenhoek Louis Pasteur Disproved spontaneous generation vaccination pasteurization

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Anton van Leeuwenhoek Developed a microscope with high resolving power He was the first to record observations of bacteria

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Anton van Leeuwenhoek His microscope His recorded observations

Theories of Microbiology : 

Theories of Microbiology Spontaneous Generation: living things arise from nonliving material The Germ Theory of Disease: microbes invade other organisms and cause disease

Disproof of Spontaneous Generation : 

Disproof of Spontaneous Generation Francesco Redi: meat & maggots Lazzaro Spallanzani: flasks of beef broth Louis Pasteur: swan neck flask

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“Swan-necked” flask that Pasteur used to disprove the theory of spontaneous generation

Pasteur’s Further Contributions : 

Pasteur’s Further Contributions Developed the technique of pasteurization to kill unwanted microorganisms Association of specific organisms with particular diseases Development of vaccines (cholera & rabies)

Robert Koch : 

Robert Koch Worked on proving germ theory His work led to the development of Koch’s postulates

Germ Theory & Koch’s Postulates : 

Germ Theory & Koch’s Postulates A pure culture of Bacillus anthracis Koch’s observations of Bacillus anthracis

Koch’s Postulates (1884) : 

Koch’s Postulates (1884) Suspect pathogenic organism should be present in all cases of the disease and absent from healthy animals Suspect organism should be grown in pure culture Cells from a pure culture of suspect organism should cause disease in healthy animal Organism should be reisolated and shown to be same as the original

Work Toward Controlling Infections : 

Work Toward Controlling Infections Ignaz Phillip Semmelweis: handwashing Joseph Lister: asepsis

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Ignaz Semmelweis (1818-1865) Proponent of handwashing based on his observations of women dying of sepsis after childbirth

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Joseph Lister & Antiseptic Surgery (1869)

Vaccination & Chemotherapy : 

Vaccination & Chemotherapy Vaccination Louis Pasteur Edward Jenner Chemotherapy Paul Ehrlich Alexander Fleming

Vaccination : 

Vaccination Edward Jenner developed a vaccine against smallpox using materials from lesions of cows infected with cowpox.

Paul Ehrlich : 

Paul Ehrlich a coworker in Koch’s lab Observed bacterial cells absorbed dyes to a greater extent than their surrounding tissue. Ehrlich reasoned a toxic dye would be absorbed by microbes & kill them leaving the surrounding tissue unharmed. developed arsenicals & injected them into mice infected with a protozoan The 606th dye tested (salvarsan) cured the protozoan infection in the mice. He also used this dye to treat successfully treat syphilis- called the “Magic Bullet”

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Alexander Fleming Discovered penicillin, the first antibiotic in 1928