History of Microbiology – outline

I. Microbiology

A. Observe microscopic organisms (microbes)

1. Bacteria

2. Viruses

3. Fungi

4. Protozoa

5. Algae

6. Helminths (parasitic worms)

B. Why is Microbiology important for you as a healthcare provider?

1. Understand infectious disease

a. Ex) sterile technique, diagnostic, treatment, risk assessment, transmission,                                                 prevention, drug resistance, etc

2. Understand immune function

3. Understand human-microbe relationship *we need them for survival




II. History of Microbiology

A. Mid-1600’s

            1. Hooke – didn’t invent but further described the uses of a microscope, increased             awareness of the “very small” of the world, first to use the term “cell”.  (Janssen invented          microscope)

2. Van Leeuwenhoek (lu en hook) (1670’s) – 1^st to see microorganisms. Described and      sketched protozoa and bacteria. Used term “animalcules”.

3. Not much further advancement in microbiology in 1700’s. Disease was still             mysterious/magic/gods explained. Science did not believe microorganisms could cause   disease – attributed to miasma (“poisonous vapors” that arose from decaying bodies).

B. Mid-1600’s to Mid-1800’s

            1. Spontaneous Generation – Argument that lifeless objects give rise to life.

a) Rotting meat gives rise to maggots. Rats spontaneously arise from garbage.

Flies come from manure, etc.

2. Redi (red ee)– (1668) showed rotting meat in a jar covered with gauze (which

prevented flies from laying eggs on meat) did not produce maggots as the meat in  the uncovered jar did. Among 1^st experiments in history of biology.

Redi’s Experiment

3. Needham – (1745) showed that even after boiling and covering microorganisms             spontaneously appeared in meat gravy. *Problem was that the boiling didn’t kill some   heat resistant bacteria (endospores) or simply bacteria got in before it was covered.

 

4. Spallanzani – (1765) did similar experiment as Needham, but boiled meat broths for a    long time. Showed that covered flasks did not contain microbes, but the uncovered broths did. Scientists countered that Spallanzani killed the “vital forces” by over boiling that are  necessary for life to spontaneously appear.

5. Arguments over spontaneous generation continued for 200 years until Pasteur.

C. Mid 1800’s – 1914 *Golden Age of Microbiology

            1. Pasteur – (1861) Swan Neck Experiment

a. Put an end to spontaneous generation

b. Pasteur Also Responsible for:

1) Fermentation – Yeast turn sugar to alcohol w/out oxygen and bacteria                                                           turn alcohol to acetic acid (vinegar) with oxygen.

2) Pasteurization – Heat solution (such as milk) high enough to kill                                                             bacteria responsible for spoilage.

2. Germ Theory of Disease

a. Microorganisms are responsible for disease.

b. Fracostoro (1500’s) – “contagion is an infection that passes from one thing to                                               another.”  (miasma)

c. Semmelweis – (1840) showed hand washing was important to prevent spread                                     of disease from autopsy room to maternity ward.

d. Pasteur reasoned that if bacteria can make wine “sick” (i.e. turn alcohol into                                          vinegar) then they can also make people and other life sick too.

e. Lister – (1867) practice of aseptic technique in surgery (phenol)

f. Koch Postulates (1876)

1. Proved Germ Theory of Disease

a. Microbes cause disease

b. Showed anthrax was caused by bacterium Bacillus anthracis

Taxonomy

A. Organizing, Classifying and Naming Living Things

B. Classification

1. Domain, kingdom, phylum, class, order, family, genus, species

2. 3 Domains

a. Bacteria

1. Prokaryotes – no true nucleus

2. Cell walls have peptidoglycan

b. Archaea (ar’kee-a)

1. Prokaryotes

2. Cell walls, if present, lack peptidoglycan

3. 3 classes

a) methanogens

b) extreme halophiles

c) extreme thermophiles




c. Eukarya (U-kar-ee-a) – have a nucleus

1. Protists (protozoa, algae, slime molds)

2. Fungi (yeast, molds, mushrooms)

3. Plants

4. Animals – like YOU!

3. 5 Kingdoms

a. Monera

1. Bacteria

2. Archaea

b. Plantae

c. Animalia

d. Fungi

e. Protista

A. Nomenclature – naming

1. Binomial (2 name) system; scientific name

2. Genus (capitalized) followed by species (not capitalized); both in italics

a. Home sapiens

b. Staphylococcus aureus

                        c. Escherichia coli   or   E. coli

 

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