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Lecture 1 Overview of Microbiology

Part 1 Microbiology: historical perspectives and

current microbial challenge

Part 2; A and B Classification of Microorganisms

(Part 2A)

Microscopes (Part 2B)

Chapter 1 and 3 preview (Part 2B)

(Cowan/Tolaro

Microbiology: A System’s Approach)

Cellular Microorganisms: The Theory of Cells

Living things are made of cells

Cells arise from preexisting cells

All cells contain nucleus and cytoplasm enclosed in a semi-permeable membrane, some cell-wall

Energy & metabolism; chemical reactions convert food into energy

Cells grow & divide, respond to environment, and can mutate

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Cellular Microorganisms: Types of Cells

Prokaryotes

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Eukaryotes

Fig. 1.5: Cowan

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Eukaryote

• Fungi e.g. yeasts, moulds

Microscopic animals

• Protozoa (unicellular) e.g. amoebae, malarial parasites

• Helminthes (multicellular) e.g. tapeworms, flukes, roundworms

Microscopic plants

• Algae (all non-pathogenic)

Prokaryotes

• Bacteria

• Actinomycetes (filamentous bacteria), e.g. Streptomyces

• Rickettsias (parasitic intracellular bacteria)

• Rickettsias

• Chlamydias

• Mycoplasmas (bacteria without cell walls)

• Phototrophic bacteria (produce oxygen in sunlight)

• Cyanobacteria, e.g. blue-green algae

• Photosynthetic, e.g. purple, purple sulphur bacteria

Viruses and prions: non-cellular organisms

CLASSIFICATION OF MICROORGANISMS

Main Types of Microorganisms: 1) Bacterium, 2) Fungus, 3) Algae 4) Virus, 5) Protozoan, 6) Helminth.

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Microorganisms vary in size –

1µm to

200 nm.

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Relative Microbial Sizes

If poliovirus (27 nm) was the size of a quarter…

Staphylococcus aureus (0.8 µm)

Escherichia coli (0.7 x 2.5 µm)

Saccharomyces cerevisiae (5 µm)

Paramecium caudatum (50 x 250 µm)

Amoeba proteus (800 µm)

McGraw-Hill 2011

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Blood agar

Mannitol salt agar

MacConkey agar

Bacterial Agar Media

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Escherichia coli

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Chlamydia Life Cycle

Gram positive cocci Gram negative bacilli

Gram Stain

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Pathogenic Bacteria

Clostridium perfringens

Treponema pallidum

Bacillus anthracis

Mycobacterium tuberculosis

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Structures Associated with Bacteria

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Flagella

Fimbrae

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Capsules

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Spores

Acellular Microorganisms

Viruses

Prions

Viroids

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Principles of Molecular Virology, Cann, Alan, 2001

Viruses take over your cells!!

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Herpes Virus in Cells

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Prions

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Aspergillus fumigatus

Penicillium species

Candida albicans

Fungus and Mold

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Protozoa

Lecture 1, Part 2A Overview of Microbiology

Microbiology: historical perspectives and current microbial challenge

Classification of microorganisms

Microscopes

Chapter 1 and 3 preview

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