1 - Humans and the microbial world

  1. Theory of spontaneous generation
    creation of living organisms from non-living material
  2. detractors of spontaneous generation
    • Francesco Redi
    • Louis Pasteur
    • John Tyndall
  3. infusion
    liquid that contains nutrients which support the growth of microorganisms
  4. endospore
    a kind of resting bacterial cell hightly resistant to heat, radiation, and disinfectants; found abundant in soil and hay infusions

    Genus/Genera: Bacillus & Clostridium
  5. disinfectant
    chemical used on inanimate objects that eliminates most pathogens (microorganisms and viruses)
  6. benefits of microorganisms
    nitrogen fixation, oxygen production, degradation of materials (cellulose, sewage, wastewater, oil spills)

    yeasts for bread, fermentation of milk (yogurt, cheese, buttermilk)

    treat radioactive waste
  7. biodiversity
    diversity in the number and distribution of species inhabiting an ecosystem
  8. biomass
    total weight of all organisms in a specific environment
  9. bacteria can synthesize
    ehtanol, pesticides, antibiotics, dietary amino acids
  10. genetic engineering
    introduce genes of one organism into an unrelated organism to confer new properties on the organism
  11. genetic engineering applications
    engineering organisms to produce medically important  products and vaccines


    engineered plants resist disease

    potentially therapeutic (gene therapy)
  12. what decreased incidences of the worst diseases
    • modern sanitation
    • vaccination
    • antimicrobial treatments
  13. past harmful diseases
    • viral disease smallpox (~10 millions deaths over 4,000 years)
    • The Black Plague (~25 million individuals)
  14. Golden age of microbiology
    • most pathogenic bacteria identified
    • work on viruses began
    • understanding that microscopic agents could cause disease led to control efforts
    • huge improvements in past century in human health (antibiotics to treat infectious diseases; vaccines to prevent diseases)
  15. what causes the most illness and deaths in the world today?
    respiratory infections and diarrheal (GI) diseases
  16. emerging disease
    disease with increased incidence in the last 20 years; changing lifestyles increase opportunities to spread and evolution of infectious agents previously unable to infect humans
  17. examples of emerging diseases
    • swine flu (2009)
    • SARS (2002)
    • MDR-TB
    • lyme disease
    • hepatitis C (HCV)
  18. reason for re-emerging disease
    • pathogens built up immunity to vaccinations
    • lack of firsthand knowledge of dangers of diseases lead people to fear vaccines more than diseases
    • declining vaccination rates (measles, mumps, whooping cough nearly eradicated from US)
    • increased travel and immigration
    • changes in population
    • chronic diseases may be caused by bacteria
  19. pathogen
    • organism/virus capable of causing disease
    • damage body tissues -> disease symptoms
    • bacteria and viruses that use the human body as a habitat for multiplcation, persistence, and transmission to other hosts
  20. reasons for resurgence of old diseases
    • increased travel
    • unvaccinated individuals susceptible to infection
    • geriatric population
    • HIV/immunocompromised
  21. normal flora/normal microbiota
    • beneficial microbes; stay for highly variable periods
    • bacteria, fungi
  22. Benefits of normal flora
    • prevent diseases by competing with pathogens
    • stimulate development of immune system response
    • aid in digestion
  23. why are microorganisms "model organisms?"
    • all cells composed of same elements
    • synthesize structures in similar ways
    • replicate DNA
    • degrade foods via metabolic pathways
Card Set
1 - Humans and the microbial world
BIOL2300 Week 1, Part 1