Microbiology Tortora

1
Microbiology Tortora

• Chapter 0ne-
• The Microbial World and You

2
Some Little Bug

• In these days of Indigestion
• It is often times a question as to what to eat
  and what to leave alone
• For each microbe and bacillus has a different
  way to kill us,
• And in time they always claim us for their own.
• There are germs of every kind in any food that
  you can find
• In the market or upon the bill of fare.
• Drinking waters just as risky as the so-called
  deadly whisky,
• And its often a mistake to breathe the air
• By Roy Atwell

3
Microbes in our lives

• Microorganisms or microbes are too small to be
  seen with the naked eye
• Includes fungi, bacteria, yeasts and molds,
  protozoa, and microscopic algae
• May cause disease (pathogens) (http//www.cdc.gov
  /ncidod/dhqp/bp.html)
• or food spoilage http//www.foodservice.com/food_s
  afety/fb6.cfm
• BUT are also beneficial (photosynthesis, food
  production, recombinant technology, waste
  treatment, etc) http//www.safe-food.org/-issue/ge
  .html

4
Naming organisms

• Binomial nomenclature was created by Carolus
  (Karl) Linnaeus
• 2 name naming (genus and species)
• Use Latin
• Genus is capitalized (Streptococcus)
• Species is small case (aureus)
• Always use italics or underline

5
Types of microorganisms

• Bacteria (singular is bacterium)-simple,
  unicellular organisms that DONT have a nucleus
  around the genetic material (prokaryotic-before a
  nucleus)
• 3 main shapes are bacillus (rodlike), coccus
  (oval or round), and spiral (corkscrew shaped)
• Usually reproduce by binary fission

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Other types

• Archaea-found in extreme environments and include
  methanogens, extreme halophiles, and extreme
  thermophiles
• Fungi-are eukaryotes because they have a true
  nucleus
• May be yeasts, molds, mushrooms
• True fungi have chitin in cell wall
• May be asexual or sexual

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Still more types

• Protozoa-unicellular, eukaryotic microbes that
  move by pseudopods, flagella, or cilia
• Algae-photosynthetic eukaryotes that play
  important role in balance of nature
• Many algae have cellulose in cell wall
• Parasites-multicellular-include flatworms and
  roundworms
• Viruses are very small (measured in nanometers),
  have only DNA or RNA surrounded by a protein coat
  (usually)

8
History of microbiology

• http//users.stlcc.edu/kkiser/History.page.html
  this site has a time line and pictures of the
  major players in early microbiology (go there to
  study!!)
• Cell theory-Hookes discovery marked the
  beginning of this
• Spontaneous generation-life from non-life
• Much early micro work was to either prove or
  disprove this theory
• Biogenesis-living cells come from pre-existing
  cells
• Aseptic technique-germ free
• Golden age of microbiology-began with Pasteurs
  work
• Germ theory of disease-proved by Koch

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Modern Chemotherapy

• Treatment of disease using chemical substances
• Synthetic versus antibiotic
• Paul Ehrlich-magic bullet-salvarsan- salvation
  from syphilis (1910)
• Alexander Fleming-accidentally discovered
  penicillin in 1928

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Modern Developments

• Bacteriology-study of bacteria, began with
  Leeuwenhoeks examination of tooth scrapings
• Mycology-study of fungi
• Parasitology-study of protozoa and parasitic
  worms
• Immunology-study of the immune system, began with
  Jenners first vaccine in 1796
• Advanced when Rebecca Lancefield classified
  Streptococcus based on differences in cell wall

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Modern Developments continued

• Virology- Iwanowski and the tobacco mosaic virus
  discovery in 1892 gave it a major boost
• Recombinant DNA technology-use microorganisms to
  manufacture human hormones and other medical
  substances (growth hormone used to come from
  cadavers)
• The technology is also called genetic engineering
  
• 1944 DNA proved to be unit of heredity (Averys
  group
• 1946 Lederberg and Tatum discovered conjugation
• 1953 Watson and Crick created model for DNA
• 1961 Jacob and Monod discovered mRNA leading to
  the understanding of protein synthesis

12
Microbes and Humans

• Recycling vital elements-nitrogen is common but
  must be changed into a usable form by bacteria to
  be available for plants and animals
• Sewage treatment-Zooglea help break down
  particulate matter in sewage treatment
• Bioremediation-using bacteria to clean up toxic
  spills
• Insect pest control -Bacillus thuringensis is
  toxic to the digestive tract of bollworms, corn
  borers, tomato worms, etc.

13
Microbes and Humans continued

• Biotechnology has now allowed gene
  therapy-inserting a missing gene into human cells
• Normal flora-populations of bacteria in and on
  you that help keep you healthy by providing
  vitamins, prevent overgrowth of harmful
  pathogens, etc

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Disease

• Infectious disease-when pathogen invades a
  susceptible host
• Emerging infectious disease-new diseases that
  have appeared in the last couple of decades
• EIDs include Avian influenza (bird flu), SARS,
  West Nile Virus, BSE or mad cow disease, CJD is
  human disease like mad cow, E-coli 0157H7,
  flesh-eating disease caused by IGAS or invasive
  group A Streptococcus, Ebola, AIDS and HIV, and
  cryptosporidiosis