history of microbiology

Ong ENH222 Winter L1 History 1

By the end of this lecture students will be able to:

Identify the contributions to early studies in microbiology made by: Van Leeuwenhoek Jenner Pasteur Koch

Recognize the scientific nomenclature of microorganisms

Recognize and classify different types of microorganisms

Week 1 Lecture: Early History of Microbiology

Science of Microbiology

Dates back only to the last 200 years

Microbes or microorganisms Found almost

everywhere

Invisible

Too small to be seen by the naked eye

Milestones in Microbiology 1665: Hooke First observation of cells

1673: van Leeuwenhoek First observation of live microorganisms

1735: Linnaeus Nomenclature for organisms

1798 Jenner First vaccine

1857: Pasteur - Fermentation

1861: Pasteur - Disproved spontaneous generation

1864: Pasteur - Pasteurization

1867: Lister Aseptic surgery

1876: *Koch Germ theory of disease

1881: *Koch Pure cultures

1882: *Koch Mycobacterium tuberculosis

1883: *Koch Vibrio cholerae

* Nobel Laureate

Microorganisms - Early Studies 17th & 18th Centuries

1665: Hooke First observation of cells

1673: van Leeuwenhoek First observation of live microorganisms



The Microscope

17th century

Robert Hooke (English scientist)

Devised compound microscope (1665)

Observed and coined the term cells

Confirmed van Leeuwenhoeks observations

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Robert Hookes microscope. Illustration from Scheme 1.

Micrographia (1665)

The Microscope 17th century

Antoni van Leeuwenhoek (Dutch cloth merchant)

Learnt to grind lenses

Made simple hand-held microscopes

Used teeth scrapings

Observed and described bacteria for the 1st time (1673-1723)

The Microscope 17th century

Course Pack Page 7 Figure 2 Tortora (11th Ed) Page 7 Fig. 1.2 Anton van Leeuwenhoeks microscope observations

Nomenclature & Classification 18th Century

Carl Linnaeus (Swedish scientist)

Established the system of scientific nomenclature (1735)

Previously non-uniform long Latin names

Gave each organism two names

Genus

Species


Nomenclature & Classification 18th Century

Genus capitalized

Species lower case

Latinized and used worldwide

Either italicized or underlined

Can be abbreviated with genus in initials

May be descriptive or honor a scientist

Nomenclature & Classification Staphylococcus aureus

S. aureus bacteria commonly found on human skin

Staphylo-

clustered arrangement

-coccus

spherical shape

aur-

Latin for golden

colour of bacterial colonies

Nomenclature & Classification

Three domains of microorganisms

Bacteria

Archaea

Eukarya

Protists

Fungi

Course Pack Page 5 Figure 1 Tortora (11th Ed) Page 5 Fig. 1.1 Types of microorganisms

Bacteria - Prokaryotes

Do not have nuclear membranes

Relatively simple single-celled organisms

Carbohydate/protein (peptidoglycan) cell walls

Divide by binary fission

Use organic chemicals, inorganic chemicals, or photosynthesis


Archaea - Prokaryotes

Cell walls lack peptidoglycan

Live in extreme environments

Methanogens

Extreme halophiles

Extreme thermophiles

Fungi - Eukaryotes

Have nuclear membranes

Molds & mushrooms multicellular masses of mycelia composed of filaments

called hyphae

Yeasts are unicellular

Chitin cell walls

Use organic chemicals for energy

Protozoa - Eukaryotes

May be motile via pseudopods, cilia, or flagella

Absorb or ingest organic chemicals

Algae - Eukaryotes

Cellulose cell walls

Use photosynthesis for energy

Produce molecular oxygen and organic compounds


Parasites - Eukaryotes

Multicellular

Helminths - flatworms and round worms

Microscopic stages in life cycles

Insects lice, mites

Viruses

Acellular

Consist of DNA or RNA core surrounded by a protein coat

Coat may be enclosed in a lipid envelope

Viruses replicate only when they are in a living host cell

Microorganisms - Early Studies 17th & 18th Centuries

1665: Hooke First observation of cells

1673: van Leeuwenhoek First observation of

live microorganisms


1798 Jenner First vaccine

Smallpox

Viral disease

Variola virus

Highly contagious

Sometimes fatal

No treatment

More WHO info on smallpox:

http://www.who.int/mediacentre/

factsheets/smallpox/en/

CDC/NIP/ Barbara Rice

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TEM

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smallpox

viruses

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Head of the

3000 year-old

mummy, of

Pharaoh

Ramses V

Smallpox - Ancient Egypt

Disease similar to smallpox described in papyrus records (3730 1555 BC)

Mummies with smallpox-like skin lesions

Pharaoh Ramses V

Died in his 30s (1157 BC)

Pustules on lower face and neck

http://www.who.int/archives/fonds_collections/bytitle/fonds_6/en/index.html

Smallpox - The New World 16th century

Carried to the Americas

Immunologically nave indigenous populations highly vulnerable to European and African infectious diseases

Spanish to the Aztecs and Incas in Central & South America

French, British & Dutch to North America

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CDC/James Gathany

CDC/James Gathany

Smallpox Vaccine

Edward Jenner (English physician)

Demonstrated that cowpox (Vaccinia virus) inoculation protected against smallpox (1796)

Successful WHO Global Eradication Campaign

1979 no more cases

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Role of Microorganisms

Early studies showed microbes exist

However not associated with:

Diseases

Infections

Food/Beverages

Dairy

Bakery

Brewery


Microbiology 19th Century

Louis Pasteur (French scientist)

Demonstrated that microorganisms are present in air (1861)

Resolved spontaneous generation controversy

How did he do this ?

Pasteurs Experiments

Open flask Sealed flask

Growth No growth

Microbiology 19th Century

Pasteurs S-shaped flasks kept microbes out but let air in

Course Pack Page 9 Figure 3 Tortora (11th Ed) Page 9 Fig. 1.3 Pasteurs experiment disproving the theory of spontaneous generation

Fermentation & Pasteurization

From Pasteurs work till beginning of World War 1 ~ 60 years

Rapid advances in microbiology

Mainly by Pasteur Fermentation is by yeasts that convert of sugar

to alcohol during brewing

Spoilage is by bacteria that turn sugar and/or alcohol into acid

Pasteurization applies heat for a short time to kill spoilage bacteria (1864)


Microbiology 19th Century Golden Age of Microbiology







Golden Age of Microbiology

Joseph Lister (British surgeon)

Used phenol to disinfect surgical wounds (1867)

Robert Koch (German scientist)

1st to prove that a specific microbe causes a specific disease (1876)

Kochs Postulates 19th century

Strict scientific criteria for associating a microorganism with a disease Found in the body in all cases of disease

Isolated from the case, grown and maintained in pure culture

Capable of producing the disease when pure culture is inoculated into susceptible animal

Retrieved from an inoculated animal

Kochs Postulates 19th century

Koch's postulate TB game

http://nobelprize.org/educational_games/medicine/tuberculosis/index.html


Microbiology 19th Century Golden Age

Aetiological Agents of Infectious Diseases







Microbiology 19th Century Golden Age continues

Discovery of more aetiologies

1882: *Koch Mycobacterium tuberculosis

1883: *Koch Vibrio cholerae

1884: *Metchnikoff Phagocytosis

Gram Gram staining procedure

Escherich Escherichia coli

1887: Petri Petri dish

1889: Kitasato Clostridium tetani

Microbiology 19th early 20th Century

Golden Age ends

1890: *von Bering Diphtheria antitioxin

*Ehrlich Theory of immunity

1892: Winogradsky Sulphur cycle

1897: *Ross - Malaria transmission by mosquitoes

1898: Shiga Shigella dysenteriae

1908: *Ehrlich Syphilis

1910: Chagas Trypanosoma cruzi

1911: *Rous Tumour-causing virus (1966 Nobel Prize)

Knowledge of Microorganisms

Allows us to

Prevent food spoilage

Prevent disease occurrence

Led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories.

Documents

history of microbiology