Chapter 1: Brief History of Microbiology Flashcards
Who observed a thin slice of cork through a microscope and
honeycomb cavities, or “cells” or
“little boxes” resembling monastery
cells – cell walls of dead cells?
Robert Hooke (1635-1703)
• Dutch merchant and scientist
• more than 400 microscopes
developed and only 9 remaining
• the first person to see tiny living
organisms in a drop of water
• “animalcules” – bacteria, protozoa,
sperm, and other small animals
Anton van Leeuwenhoek (1632-1723)
Spontaneous Generation
life can arise from nonliving matter
Aristotle
one of the earliest scholars to articulate this theory – evidenced the
appearance of animals from environments previously devoid of such animals, such as
the seemingly sudden appearanceof fish in a new puddleof water.
- Italian physician
- performed an experiment in 1668 to
refute spontaneous generation
∴ Maggots could only form when flies
were allowed to lay eggs in the meat,
and that the maggots were the
offspring of flies, not the product of
spontaneous generation.
Francesco Redi (1626–1697)
Who demonstrated that maggots were the offspring of flies, not
products of spontaneous generation?
Francesco Redi (1626–1697)
Who argued that microbes
arose spontaneously in broth from a “life force?
John Needham (1713-1781)
-Tried to prove spontaneous
generation.
-Flaw with his experiment: the flask
was not sealed and was exposed to
air (NEEDham NEEDed to fix his
experiment)
John Needham (1713-1781)
Whose
experiments with broth aimed to disprove those of Needham?
Lazzaro Spallanzani (1729-1799)
- boiled flask of gravy to kill life, sealed one jar, left other jar open
- open jar had living microorganisms,
sealed jar did not
∴ Gravy did not produce life, organisms entered through the air
Lazzaro Spallanzani (1729-1799)
- it postulates the production of new living organisms from pre-existing life
- is based on the theory that life can only come from life, and it refers to any process by which a life form can give rise toother life forms.
Biogenesis theory
- Polish-born, German scientist
- Omnis cellula e cellula(“All cells
come from cells”) – the second tenet
of modern cell theory - popularized the cell theory in an
1855 essay entitled “Cellular
Pathology”
Rudolf Virchow (1821–1902)
- French chemist
- 1858 – Pasteur filtered air through a
gun-cotton filter and, upon
microscopic examination of the cotton,
found it full of microorganisms,
suggesting that the exposure of a broth
to air was not introducing a “life force”
to the broth but rather airborne
microorganisms - disproved the theory of spontaneous
generation
Louis Pasteur (1822–1895)
- 1857 – 1914
- rapid advances led tothe the establishment of microbiology
First Golden Age of Microbiology
- agents of many diseases and the role of immunity in preventing and curing disease
- chemical activities of microorganisms
- improved the techniques for performing microscopyand culturing microorganisms
- developed vaccines and surgical techniques
Discoveries and studies of First Golden Age of Microbiology
process of food preservation that uses mild heat to destroy pathogens and extend shelf life of certain foods and beverages123.
Pasteurization
refers to the metabolic process by which organic molecules (normally glucose) are converted into acids, gases, or alcohol in the absence of oxygen or any electron transport chain.
Fermentation
Certain diseases are caused by the invasion of the body by microorganisms
Germ Theory
- Microbes can cause illnesses within the body.
- Microbes (and thus the illnesses) can spread from one person to another.
- A specific microbe exists for each illnesses which will always invoke the same
illnesses.
Based on three basic underlying principles that developed throughout the
history of medicine (The Discovery of the Germ by John Waller).
propse miasma theory
Ancient Greeks
1665- Hooke
observes cork cells under a microscope
1546- Francastoro
begins early version of germ theory in De Contagione et Contagiosis Morbis
1674- van Leeuwenhoek
observed single-celled organisms
1847- Semmelweis
demonstrates that hand washing reduces puerperal infections
1854-Snow
demonstrates that cholera bacteria were transmitted in contaminated drinking water
1862-Pasteur
disproves spontanous generation with swan-neck flask experiment
1856- Pasteur
discovers microbial fermentation while studying the causes of spoilage in beer and wine
1867- Lister
begins using carbolic acid as a disinfetant during surgery
1876-1907: Koch and his workers
determine causative agents for many bacterial infections
- British physician
- smallpox vaccine (Ln. “vacca” – cow)
- not only inoculated cowpox, but also
proved that they are immune to
smallpox (cowpox virus is closely
related to variola, the causative virus
of smallpox) - demonstrated that the protective
cowpox could be effectively
inoculated from person to person,
not just directly from cattle
Edward Jenner (1749-1823)
They used a method of “nasal
insufflation by blowing powdered smallpox material, usually scabs, up the nostrils through a silver tube.
first vaccination for variola, smallpox
the search for substances that could destroy pathogenic microorganisms without damaging
the infected animal or human
Second Golden Age of Microbiology
treatment of diseaseby usingchemical substances
Chemotherapy
chemicals produced naturally by bacteria and fungi that act against other
microorganisms
Antibiotics
chemotherapeutic agents prepared from chemicals in the laboratory
Synthetic drugs
Quinine
* a component of the bark of the cinchona
(quina-quina) tree, was used to treat
malaria from as early as the 1600s
The First Synthetic Drugs
- German physician and scientist
- 1910 – Salvarsan 606 (arsenic
derivative); he called it the “magic
bullet” because it homed in on and
destroyed the harmful bacteria that
causes syphilis
Paul Ehrlich (1854-1915)
- Scottish physician and
microbiologist - 1928 – discovered penicillin, from
Penicillium notatum (or P.
chrysogenum) the first true
antibiotic
Alexander Fleming (1881-1955)
- new pathogenic bacteria discovered
- 1997 - Heide Schulz discovered the largest bacterium Thiomargarita namibiensis
Bacteriology
- agricultural and ecological, including
- medical – diagnosis and treatment of fungal infection (10% hospital-acquired
infections)
Mycology
infestations among immunosuppressed patients (organ transplants, cancer
therapy, or AIDS)
Parasitology
- vaccine availability
- 1960 – discovery of interferons
Immunology
released by cells infected
with a virus, leukocytes, and other
immune cells.
Interferons
limit the infection,
responses of cells to interferon
inhibition of protein synthesis, activation
of immune cells, etc.
relationship between genes and
enzymes
Molecular Genetics
George W. Beadle and Edward L. Tatum (1940s)
DNA as hereditary material
Oswald Avery, Colin MacLeod, and Maclyn McCarty
Genetic material could be transferred from
one bacterium to another by a process called conjugation.
Joshua Lederberg and Edward L. Tatum
structure and replication of DNA
James Watson and Francis Crick (1950s)
Paul Berg (1926-2023)
Third Golden Age of Microbiology
