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Introductory Microbiology

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The study of of organisms (microorganisms or microbes) too small ... Amoeba. The Microbes. 5. Misc. Large, multicellular. Worms. Helminths. Arthropods. Insects ... – PowerPoint PPT presentation

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Title: Introductory Microbiology


1
Introductory Microbiology
  • Dr. Heather Townsend
  • Summer 2009

2
Microbiology
  • The study of of organisms (microorganisms or
    microbes) too small to be seen without
    magnification
  • This includes
  • Bacteria
  • Viruses
  • Fungi
  • Protozoa
  • Helminths (worms)
  • Algae

3
The Microbes
  • 1. Bacteria
  • Single-celled organisms
  • Various shapes
  • Spherical
  • Rod
  • Spiral shapes
  • Cellular
  • Lack membrane-enclosed cellular structures
  • Widely distributed in nature

Klebsiella pneumoniae, bacteria that causes
pneumonia in humans
4
The Microbes
  • 2. Viruses
  • Acellular
  • Composed of nucleic acid and a few proteins
  • Replicate themselves to display other properties
    of living organisms when they invade living cells

Bacteriophages observed at 35,500X
5
The Microbes
  • 3. Fungi
  • Yeasts and molds
  • Single-celled, microscopic
  • Mushrooms
  • Multicellular, macroscopic
  • Cell nucleus and other cellular structures
  • Absorb nutrients from their environment
  • Widely distributed in water and soil
  • Act as decomposers of dead organisms

Philobolus crystallinus, fruiting bodies of this
fungus
6
The Microbes
  • 4. Protozoa
  • Single-celled, microscopic organisms
  • Have at least one nucleus and many cellular
    structures
  • Obtain food by engulfing or ingesting smaller
    organisms
  • Most can move
  • Found in many different environments

Amoeba
7
The Microbes
  • 5. Misc.
  • Large, multicellular
  • Worms
  • Helminths
  • Arthropods
  • Insects

Tapeworm Head
8
The Microbes
  • 6. Algae
  • Single-celled microscopic organisms
  • Have a nucleus and many membrane-enclosed
    cellular structures
  • Photosynthesize their own food
  • Widely distributed in fresh and salt water
  • Important source of food for other organisms

Micrasterias, a green algae living in fresh
water.
9
Branches of Study Within Microbiology
  • Immunology
  • studies immune chemicals and cells that are
    produced in response to infection
  • Public health microbiology epidemiology
  • aim to monitor and control the spread of diseases
    (CDC)
  • Food, dairy and aquatic microbiology
  • examine the ecological and practical roles of
    microbes in food and water
  • Biotechnology
  • ranges from bread making to gene therapy
  • Genetic engineering recombinant DNA technology
  • altering the genetic makeup of organisms

10
Microbes Are Involved In
  • nutrient production energy flow
  • i.e., photosynthesis
  • decomposition and nutrient recycling
  • production of foods, drugs vaccines
  • bioremediation
  • causing disease

11
(No Transcript)
12
Impact of Pathogens
  • Pathogens
  • Diseases-causing agents
  • Nearly 2,000 different microbes cause diseases in
    the human body
  • 10 B infections/year worldwide
  • 13 M deaths from infections/year worldwide
    killing about 1/3 of the U.S. population each year

13
Impact of Pathogens
  • Emerging diseases
  • Becoming more prominent over the years
  • Zoonosis
  • SARS
  • Reemerging
  • Older diseases increasing in occurrence
  • TB
  • Malaria
  • Hepatitis
  • Noninfectious diseases

14
Characteristics of Microbes
  • Prokaryotic cells
  • Smaller
  • Lack special structures such as a nucleus and
    organelles
  • All prokaryotic cells are microorganisms
  • Only some microorganisms are eukaryotic

15
Lifestyles of Microorganisms
  • Free existence
  • Close associations
  • Parasites
  • hosts

16
Antonie van Leeuwenhoek
  • First to observe living microbes
  • His single-lens magnified up to 300X

(1632-1723)
17
Early Medical Microbiology
  • Louis Pasteur
  • Worked in the wine industry
  • Had knowledge about yeast producing alcohol
  • Swan-neck flasks
  • Tipping the flask would allow the microbes to
    enter the infusion
  • Cause them to become cloudy
  • Main experiment that helped disprove spontaneous
    generation

18
Early Medical Microbiology
  • Pasteur discovered that some yeasts made good
    tasting wine
  • Mixtures of microbes competed with yeast and made
    wine taste oily or sour
  • Developed Pasteurization to deal with this
    problem
  • Heated the wine to 56C without oxygen present
    for 30 minutes
  • Developed a rabies vaccine

19
Early Medical Microbiology
  • Robert Koch (120 years ago, German)
  • Linked a microscopic organism with a specific
    disease (anthrax)
  • Developed method to grow bacteria in pure
    cultures (cultures containing only one kind of
    organism)
  • Used solidified gelatin from potato slices mixed
    with agar
  • Creates a firm surface that microbes could grow
    on

20
Kochs Postulates
  • The specific causative agent must be found in
    every case of the disease
  • The disease organism must be isolated in pure
    culture
  • Inoculation of a sample of the culture into a
    healthy, susceptible animal must produce the same
    disease
  • The disease must be covered from the inoculated
    animal

21
Early Medical Microbiology
  • Oliver Wendell (American physician)
  • observed mothers who gave birth at home
    experienced fewer infections than those that gave
    birth in a hospital
  • Ignaz Semmelweis (Hungarian doctor)
  • showed that women became infected with puerperal
    fever during delivery by doctors coming directly
    from the autopsy room

22
Early Medical Microbiology
  • Joseph Lister (English surgeon)
  • Introduced aseptic techniques
  • Aimed at reducing microbes in a medial setting
    and preventing wound infections
  • Improved sanitation
  • Promotes use of carbolic acid on bandages and
    medical instruments

23
Spontaneous Generation Theory
  • Germ theory of disease
  • Microorganisms can invade other organisms and
    cause disease
  • Many diseases are caused by the growth of
    microbes in the body and not by sins, bad
    character, or poverty, etc.
  • Spontaneous generation
  • Living things arise from nonliving things
  • Belief that some forms of life could arise from
    vital forces present in nonliving or decomposing
    matter
  • Maggots found in rotting meat arose from a
    nonliving factor
  • Microorganisms found in broth that made it cloudy
    appeared from a nonliving factor

24
What to expect..
  • Different microorganisms
  • How to detect microorganisms
  • Common disease caused by microorganisms
  • How to control the spread of microorganisms
  • Immune system
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