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Jan 1, 1546
Italian physician Girolamo Fracastoro suggests that invisible organisms may cause disease. Fracastro writes a poem about a shepherd named Syphilis who insults the Apollo, and is punished with a terrible disease (1546).
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Robert Hooke publishes Micrographia (1665). Coins the term “CELL” for the structures he sees in a piece of cork.
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Charles de L'Orme invents the Plague Doctor costume (1669).
For centuries, people believed that an unseen force called “miasma” or ‘bad air’ caused plagues and deaths. When hit by waves of the Plague, many towns hired Plague ‘doctors’, who wore a special costume. The beak-like pouch held herbs that were thought to protect the 'doctors' against the ‘miasma’. A wooden cane stick was used to examine the patients without direct touching. Right notions, but wrong conclusions. The ‘miasma’ theory later vaporized to give way to the germ theory of disease. -
“The first microbiologist”: Antony van Leeuwenhoek, a Dutch cloth maker, and amateur lens grinder, observes live individual bacteria and protozoa using his homemade microscope.
His lenses were remarkably good, and gave magnifications of up to 300x (1676) -
Spallanzani’s experiments dispute the theory of spontaneous generation. Supports the idea that life must come from pre-existing life (1767).
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Edward Jenner pioneers vaccination (1796).
He observes that milkmaids who got cowpox infections were spared from smallpox. Takes cowpox lesion material from a milkmaid and vaccinates a young boy, James Phipps. Six weeks later, he exposes the boy to pus from a smallpox victim. Luckily (especially for the kid), Jenner’s hypothesis was correct – James Phipps did not get smallpox! -
Theodor Schwann & Mathias Schleiden independently propose that the cell is the basic unit of life, and that all organisms are composed of cells (1838).
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The German physician Friedrich Henle presents a clear exposition of the germ theory of disease (1840).
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S. Kitasato discovers the causative agent of tetanus, Clostridium tetani (1884).
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Ignaz Semelweis, a Hungarian physician, becomes the firstperson to recognize nosocomial (hospital-acquired) infections, and theimportance of handwashing. (1847-1850).
Childbearing women were always at risk for childbed/puerperal fever, but the incidence increased when women started delivering babies in hospitals. Noticing that women in wards managed by doctors were four times more likely to develop the disease than in wards managed by midwives, Semelweis reasoned that doctors, who went to the wards after performing autopsies, were actually transferring the 'poison' (now we know it is bacteria) to the delivery rooms. -
Heinrich Anton deBary demonstrated that microorganisms, particularly fungi, caused diseases in plants (1853).
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John Snow, a British physician, considered as the 'Father ofepidemiology', performs meticulous studies to show that contaminated waterwas responsible for the epidemic spread of cholera. (1853-54).
At that time, there was no consensus on what caused cholera, and treatments were completely random. Using meticulous reasoing, graphs and maps, Snow showed that Cholera was
caused by contaminated water, and not by "miasma" or 'foul air'.
Extra extra: Two excellent sources (and a must read for anyone interested in infectious diseases) about John Snow: (1) http://www.ph.ucla.edu/epi/snow.html and (2) “The medical detective” by Sandra Hempel. -
Theodor Escherich identifies Escherichia coli as a natural inhabitant of the human gut (1885)
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Louis Pasteur (& others) pioneers the field of microbiology by disproving the theory of spontaneous generation, and establishing that microorganisms were the agents responsible for many diseases.(1857-1885)
He develops the method of 'pasteurization' to destroy unwanted microbes in wine. His contributions places the germ theory of disease on a firm scientific footing. He demonstrated the basis of parasitic diseases in silk worms, determined the cause of rabies and developed a vaccine for it, and developed immunization methods to prevent chicken cholera. Pasteur also discovered anaerobiosis, and developed a vaccine for anthrax. -
Gregor Mendel does pioneering work on genetics (1866).
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Joseph Lister starts the modern era of aseptic surgery by publishing the first work on antiseptic surgery (1867).
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Ferdinand J. Cohn published an early classification of bacteria and first used the genus name Bacillus (1875).
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Robert Koch defines the criteria for determining whether aparticular organism is responsible for a given disease (Koch's postulates).Robert Koch, describes the disease cycle of anthrax, isolates the tuberclebacillus and identifies the cholera bacterium
Koch pioneered the methods for preparing microscopic slides and photographing bacteria, and developed the technique for isolating pure bacterial cultures by streaking them on solid plates. In 1890, he presented the eponymously named 'Koch's postulates' for determining whether a given organism caused a specific disease. Koch is awarded the Nobel Prize for Medicine in 1905 (Source: Gut Microbes, July/August 2011). -
Ferdinand Cohn discovers the bacterial spore and shows its resistance to sterilization (1877).
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Walther & Fanny Hesse use agar as a solidifying gel for culture media (1881).
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Elie Metchnikoff launches the study of immunology by discovering phagocytic cells (macrophages). 1884.
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Christian Gram publishes a paper describing the Gram stain (1884).
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Theodor Escherich identifies Escherichia coli as a natural inhabitant of the human gut (1885).
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Julius Petri develops, of course, the Petri dish – an elegantly simple dish for growing bacteria and minimizing contamination (1887).
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David Bruce identifies Brucella melitensis as the causative agent of brucellosis in cattle (1887).
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Paul Ehrlich proposes that antibodies are responsible for immunity (1890). He develops Salvarsan (the "magic bullet") to treat syphilis(1912), and spurs the exploration of chemical compounds to combat infections. Receives Nobel Prize in 1908.
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Diphtheria antitoxin developed by Emil Von Behring (1890). Nobel Prize in 1901.
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Mendel's heredity experiments rediscovered independently by three scientists (1900).
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Sir Ronald Ross receives the Nobel Prize for describing the life cycle of the malaria parasite (1902).
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Charles Louis receives the Nobel Prize for his work on disease-causing protozoa (1907).
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Fredrick Griffith discovers genetic transformation in bacteria (1928).
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Discovery of penicillin by Alexander Fleming (1929).
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Gerhardt Domagk discovers the antimicrobial properties of sulfur-containing compounds (1935). Receives the Nobel Prize in 1939.
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Selma Waksman presents his work on antibiotic (actinomycin, streptothricin, cycloserines and novobiocin) production by actinomycetes (1941). Receives Nobel Prize in 1952.
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George Beadle and Edward Tatum present evidence of genetic mutants, and open the field of molecular genetics (1941).
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Oswald Avery, Colin MacLeod and Maclyn McCarthy discover that DNA is the transforming principle that confers new properties to bacteria. Joshua Lederberg & Edward Tatum show that DNA can be transferred from one bacterium to another (1944).
Lederberg & Tatum receive the Nobel Prize in 1958, (with George Beadle). -
Fleming, E. B. Chain & H.W. Florey receive the Nobel Prize for discovery of penicillin (1945).
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James Watson, Francis Crick, Rosalind Franklin and Maurice Wilkins determine the structure of DNA (1953). Receive Nobel Prize in 1962.
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Hans Adolf Krebs discovers his cycle! (1953)
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Jonas Salk develops the polio vaccine (1954).
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Severo Ochoa & Arthur Kornberg receive Nobel Prize for discoveries on the synthesis of DNA and RNA (1959).
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Rene Dubos works on antimicrobial agents and environmental protection F. M. Burnet and Peter B. Medawar receive Nobel Prize for the discovery of acquired immunological tolerance (1960).
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Max Delbruck, Alfred Hershey and Salvadore E. Luria receive Nobel Prize for describing the mechanism of viral infection of bacterial cells (1969).
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Herbert Boyer and Stanley Cohen, using plasmids, are the first to clone DNA (1973).
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Carl Woese describes the three domains of life (1977).
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The WHO declares the worldwide eradication of small pox (1980).
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The Australian physicians Barry Marshall & Robin Warren demonstrate that the bacterium Helicobacter pylori causes peptic ulcer disease (1982-1984).
To prove this, Barry Marshall ingested a culture of H. pylori, and developed disease symptoms in five days. -
PCR (polymerase chain reaction) invented by Kary Mullis (1983).
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Haemophilus influenzae: First bacterial genome completely sequenced (1995).
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Autoimmune arthritis is linked to bacterial infection (1998).
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Zyvox, first new antibiotic in 35 years, approved by the FDA (2000).
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Obesity is linked to alterations in the human gut microflora (2008).
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Human microbiome project is launched (2008). The goal is to identify and characterize the microbes found in association with healthy & diseased humans.
