This document provides an overview of key concepts in microbiology. It discusses [1] the study of microorganisms like bacteria, viruses, fungi and protozoa, [2] the branches of microbiology including immunology and food/water microbiology, [3] the impact of microbes including their role in nutrient production and disease, and [4] pioneers like Antonie van Leeuwenhoek who first observed microbes under a microscope and Louis Pasteur who disproved spontaneous generation.
1. PowerPoint to accompany
Foundations in Microbiology
Fifth Edition
Talaro
Chapter
1
Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2. Microbiology
• The study of of organisms too small to be
seen without magnification
– bacteria
– viruses
– fungi
– protozoa
– helminths (worms)
– algae
2
3. Branches of study within
microbiology
• Immunology
• Public health microbiology & epidemiology
• Food, dairy and aquatic microbiology
• Biotechnology
• Genetic engineering & recombinant DNA
technology
3
4. Microbes are involved in
• nutrient production & energy flow
• decomposition
• production of foods, drugs & vaccines
• bioremediation
• causing disease
4
5. Impact of pathogens
• Nearly 2,000 different microbes cause
diseases
• 10 B infections/year worldwide
• 13 M deaths from infections/year worldwide
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11. Scientific Method
• Form a hypothesis - a tentative explanation
that can be supported or refuted by
observation & experimentation
• A lengthy process of experimentation,
analysis & testing either supports or refutes
the hypothesis.
• Results must be published & repeated by
other investigators.
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12. • If hypothesis is supported by a growing
body of evidence & survives rigorous
scrutiny, it moves to the next level of
confidence - it becomes a theory
• Evidence of a theory is so compelling that
the next level of confidence is reached - it
becomes a Law or principle
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13. Spontaneous generation
Early belief that some forms of life
could arise from vital forces present in
nonliving or decomposing matter.
(flies from manure, etc)
14. Louis Pasteur
• Showed microbes caused
fermentation & spoilage
• Disproved spontaneous
generation of m.o.
• Developed aseptic
techniques.
• Developed a rabies vaccine.
(1822-1895) 14
15. Germ theory of disease
Many diseases are caused by the growth
of microbes in the body and not by sins,
bad character, or poverty, etc.
16. Robert Koch
• Established a sequence of
experimental steps to
show that a specific m.o.
causes a particular
disease.
• Developed pure culture
methods.
• Identified cause of
anthrax, TB, & cholera.
(1843-1910) 16
17. Taxonomy - system for organizing,
classifying & naming living things
• Domain - Archaea, Bacteria &
Eukarya
• Kingdom - 5
• Phylum or Division
• Class
• Order
• Family
• Genus
• species
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18. 3 domains
• Eubacteria -true bacteria, peptidoglycan
• Archaea –odd bacteria that live in extreme
environments, high salt, heat, etc
• Eukarya- have a nucleus, & organelles
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20. Naming micoorganisms
• Binomial (scientific) nomenclature
• Gives each microbe 2 names
– Genus - noun, always capitalized
– species - adjective, lowercase
• Both italicized or underlined
– Staphylococcus aureus (S. aureus)
– Bacillus subtilis (B. subtilis)
– Escherichia coli (E. coli)
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21. Evolution- living things change
gradually over millions of years
• Changes favoring survival are retained &
less beneficial changes are lost.
• All new species originate from preexisting
species.
• Closely related organism have similar
features because they evolved from
common ancestral forms.
• Evolution usually progresses toward greater
complexity. 21