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Chapter 1

Chapter 1 . The Microbial World and You. What are microorganisms?. Too small to be seen with the unaided eye True cellular forms Ubiquitous Both helpful and problematic. Scope and Relevance of Microbiology. First living organisms on the planet Live everywhere life is possible

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Chapter 1

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  1. Chapter 1 The Microbial World and You

  2. What are microorganisms? • Too small to be seen with the unaided eye • True cellular forms • Ubiquitous • Both helpful and problematic

  3. Scope and Relevance of Microbiology • First living organisms on the planet • Live everywhere life is possible • Largest component of Earth's biomass • The entire ecosystem depends on their activities

  4. Why study microbes? • Recycling vital elements • Bioremediation • Agriculture • Molecular Biology and Biotechnology • Food microbiology • Industrial Microbiology • Disease causing microorganisms

  5. Common Ancestor • Gave rise to 3 Domains • Two prokaryotic • Bacteria and Archaea • One eukaryotic • Eukarya

  6. Prokaryotes • Asexual; unicellular, no membrane bound organelles • Archaea • Not known to be human pathogens • Usually found in extreme environments • Bacteria • Some pathogenic • Multiple morphological and physiological differences from archaea

  7. Rod Shaped Bacteria Round Archaea Many Klebisella pneumoniae cells Methanococcus janaschii, with numerous flagella attached to one side

  8. Eukaryotes • Unicellular or multicellular • Sexual and asexual reproduction • Multiple membranous organelles • Algae • Unicellular or multicellular • Photosynthetic • High morphological diversity • Not pathogenic

  9. Cymatopleura Volvox Macrocystis pyrifera Gelidium pulchrum Alexandrium tamarense

  10. Fungi • Unicellular or multicellular • Absorb nutrients from their environment • Primarily opportunistic pathogens Saccharomyces cerevisiae Rhizopus Aspergillus flavus Amanita muscaria

  11. Protozoa • Unicellular • Most are mobile • Pseudopods, Flagella, Cilia • Absorb nutrients from environment or live as parasites • Manyare pathogenic

  12. Amoeba Giardia lamblia Paramecium

  13. Helminths • Multi-cellular animals • Flatworms and round worms • Many are pathogenic • Only some life stages microscopic Taenia taeniformis Necator americanus

  14. Viruses • Living or non-living??? • Obligatory intracellular parasite • No true cellular organization HIV virus on the surface of a CD4+ cell Bacteriophages

  15. Size in the Microbial World

  16. History of Microbiology • Robert Hooke -1665 • Anton van Leeuwenhoek - 1673 • "animalcules" • Schleiden and Schwann- 1838/39 • Cell theory

  17. Spontaneous Generation • Franscesco Redi – 1668 • John Needham – 1745 • Lazzaro Spallanzani - 1765

  18. Rudolf Virchow -1855 • Louis Pasteur – 1861 • Aseptic techniques

  19. Golden Age of Microbiology (1874 – 1914)

  20. Support theories that invisible agents cause disease • IgnazSemmelweis - 1840 • Childbed fever • Joseph Lister - 1867 • Aseptic surgery • John Tyndall • Microbes in dust, some heat resistant

  21. Germ Theory of Disease • Pasteur • Fermentation (1857) and pasteurization (1864) • Robert Koch - 1876 • Walther Hesse – 1882

  22. Vaccination • Edward Jenner – 1798 • Smallpox vaccine • Louis Pasteur – 1880 • Avirulence • Rabies vaccine

  23. 1908, Paul Ehrlich Salvarsan – treatment for syphilis 1928, Alexander Fleming Discovered properties of penicillin 1935-36, Gerhard Domagk & Ernest Fourneau Development of sulfa drugs Chemotherapy

  24. 1940, Selman Waksman • Isolated antibiotic from Streptomyces • 1940, Howard Florey & Ernest Chain • Preformed clinical trials and mass produced penicillin

  25. Problems with modern chemotherapeutics • Toxicity • Resistance • Lack of adequate anti- viral drugs

  26. Infectious disease remains a threat • 750 million cases each year in US • Emerging diseases • Factors associated with emerging disease • Microbial evolution • Changing human behavior/lifestyles • Complacency of human population • Population expansion/global travel

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