Microbes, Scientistis

Edward Jenner

Father of immunology; discovered vaccines in 1796 after observing that milkmaids exposed to cowpox did not contract smallpox

Benjamin Jesty

In 1774, 20 years before Jenner, gave his wife and two sons cowpox using a darning needle; the family survived smallpox

Louis Pasteur

Father of microbiology; contributed to biogenesis theory, pasteurisation and vaccines

Biogenesis theory

The theory that living things come from other living things

Pasteurisation

Heating food to destroy microbes

Attenuation

Weakening a virus so it does not harm the host; used by Pasteur in vaccine development

Ignaz Semmelweis

Suggested handwashing to midwives on hospital wards

Joseph Lister

Advocate and developer of antisepsis and sterilisation of surgical instruments

Robert Koch

Formally demonstrated microbes as disease agents (germ theory of disease) and developed Koch's postulates

Germ theory of disease

The theory that microbes cause disease

Koch's postulates

Four criteria designed to establish a causal relationship between a microbe and a disease

Koch's postulate 1 (Association)

The suspected microorganism must be found in all cases of the disease and absent in healthy organisms

Koch's postulate 2 (Isolation)

The microorganism must be isolated from a diseased host and grown in pure culture in a laboratory

Koch's postulate 3 (Inoculation)

A sample of the pure culture must cause the same disease when introduced into a healthy, susceptible host

Koch's postulate 4 (Re-isolation)

The microorganism must be re-isolated from the newly infected host and shown to be identical to the original microorganism

Paul Ehrlich

Called antibiotics magic bullets; discovered Salvarsan in 1906, which specifically killed infectious microbes without ill effects on the patient and was used to treat syphilis

Salvarsan

Drug discovered by Paul Ehrlich in 1906 to treat syphilis

Alexander Fleming

Did not discover antibiotics; was the first to observe living organisms producing antibiotics

Howard Florey and Ernst Chain

Isolated penicillin from the fungus Penicillium notatum