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1 intro and history (bio 211)vo

  1. Relevance and History of Microbiology General Microbiology BIO 211 Dr. Miller
  2. Objectives Introduction to Microbiology • Learn the scope and range of microbiology study (ubiquity and diversity) • Describe broad taxonomic classifications of microorganisms • Understand the importance of microorganisms and the effect they have on human populations • Describe the advent of the microbiology field from a historical perspective
  3. What is microbiology? 1. Micro: too small to be seen with the naked eye 2. Bio: life 3. Logy: study of In general microbiology is the study of microorganisms
  4. Microorganisms are DIVERSE!!! • Microorganisms are found across every taxonomic group – Bacteria (Bacteria and Archaea) – Fungi (Fungi/Myceteae) – Protozoa (Protista) – Algae (Protista) – Parasites (Animalia) – Viruses ( ? )
  5. System of Classification • Five Kingdom system azImages/FiveKingdoms%20Animals2.jpg
  6. System of Classification • Three Domain System
  7. System of Classification • Six Kingdom System
  8. System of Classification Domain Kingdom Phylum Class Order Family Genus Species Humans E. coli (6 Kingdom) Eukarya Bacteria/Eubacteria Animalia Bacteria/Eubacteria Chordata Proteobacteria Mammalia Gama Proteobacteria Primates Enterobacteriales Hominidae Enterobacteriaceae Homo Escherichia H. sapiens E. coli
  9. Microorganisms are UBIQUITIOUS!!! • Microorganisms are found nearly everywhere – On/in bodies – On surfaces – In the air – In water – In extreme environments: deep sea thermal vents, polar ice caps, sulfur and salty lakes
  10. Microorganisms are IMPORTANT!!! (positive) 1. Nutrient production and energy flow – Engage in photosynthesis – Produce oxygen – Food chain 2. Decomposition and nutrient recycling – Recycle chemical elements and direct them back to natural cycles of living organisms. 3. Biotechnology/Genetic Engineering – Can be manipulated to produce proteins for our use (i.e. insulin, human growth hormone) – Used as a genetic model organism 4. Bioremediation – Used to restore stability or clean up pollutants
  11. Microorganisms are IMPORTANT!!! (negative) Impact on Human Health • Only 1% of known bacteria cause human disease • Annual world wide death toll from infections is 12 million people – 3 million from malaria alone
  12. Worldwide Infectious Disease
  13. • Notice how many deaths are caused by microorganisms • Notice the difference between the US and worldwide Today we understand the impact microorganisms have on our life. Historically their importance was not recognized!
  14. Historical Perspective • 400 B.C. Hippocrates – Medicine is distinct from theology and philosophy – Set forth ethical standards for the practice of medicine • 100 B.C. Roman scholars – Proposed that tiny animals entered the mouth and nose to cause disease • Disease, infection, and death was recognized as contagious and perhaps even caused by “minute bodies” or “foul foreign earthly bodies” however, their study was inhibited due to a lack of scientific tools. – 542-1650 A.D. The Black Death (bubonic plague) killed 10s of millions of people in the Mediterranean and Europe. Jewish population less affected due to Hebrew sanitation laws
  15. Spontaneous Generation • Existed ~300B.C. through the mid 1800s • Theory that microorganisms arose from non- living things (seeing is believing) – Maggots from dead meat – Bacteria from old broth • As long as people believed that living could arise from non-living there was no need to understand how diseases were transmitted and controlled!!!
  16. Beginning of Microbiology • Scientists (and others) began to change traditional ideas about disease and microorganisms in the mid 1600s 1. Tools • Anton van Leeuwenhoek (Dutch merchant): 1670s. 1st lenses and later the 1st to examine/document living microorganisms • Robert Hooke (English scientist): Used a compound microscope . Coined the term cell. 2. New hypothesis (theory): Germ Theory of Disease • Microorganisms can invade other organisms and cause disease • Met with lots of resistance from the scientific community (previous theory lasted for 2100 years)
  17. Germ Theory of Disease Proponents • Francesco Redi (Italian physician): 1688 2/chapter6/image/spallanzani-experiment.jpg • John Needham (English priest): 1748 • Lazzaro Spallanzani (Italian priest): 1760s • Challenges spontaneous generation • Tested decaying meat’s ability to produce maggots • Challenges spontaneous generation • Boiled broth and sealed it
  18. Germ Theory of Disease Proponents • Ignaz Philipp Semmelweis (Austrian physician): 1847 – Introduced hand washing practices – Childbed fever • (decrease the mortality rate from 35% to 1%) – Largely ignored during his lifetime • Joseph Lister (English surgeon): 1867 – Introduced phenol as a disinfectant – Decrease post-operative infections
  19. Germ Theory of Disease Proponents-The Final Blow Y1pj8I/AAAAAAAAACQ/hsehi4O0DV0/s200/1_6.gif • John Tyndall (English physicist): 1860s • Louis Pasteur (French chemist): 1861 • Swan neck flasks • Placed sealed flasks of boiled infusions in an airtight box. After the dust settled he removed the covers from the flasks. The flasks remained sterile. First evidence against spontaneous generation was in 1688. Wasn’t finally accepted by the scientific community until 1861.
  20. Other Significant Events in Microbiology History • 1796: Edward Jenner introduces cowpox vaccination for smallpox • 1838 & 1839: Schwann and Schleiden propose cell theory – Plants and animals are made up of cells – These cells are essential to the structure and function of organisms • 1884: Hans Christian Gram develops the Gram stain technique
  21. Other Significant Events in Microbiology History 1876: Identifies Bacillus anthracis as the causative agent of anthrax 1882: Identifies Mycobacterium tuberculosis as the causative agent of tuberculosis 1884: Develops Koch’s postulates. Still used today in identifying causative agents of disease 1857: Developed pasteurization 1861: Refuted spontaneous generation 1881: Developed anthrax vaccine 1885: Developed rabies vaccine Louis Pasteur Robert Koch
  22. Other Significant Events in Microbiology History • 1903: Wright and others discover antibodies • 1929: Alexander Fleming discovers the first antibiotic (penicillin) • 1953: Watson and Crick propose DNA double helix • 1954: Jonas Salk develops polio vaccine • 1976: First whole genome to be sequenced (RNA virus) • 1979: Smallpox is officially declared eradicated • 1983: HIV is isolated and identified • 1990: First human gene therapy • 1995: First bacterial genome is sequenced • 2002: Infectious poliovirus is made from basic chemicals SIGNIFICANT findings are still being made today!
  23. Conclusions • Microorganisms span all taxonomic kingdoms • Microorganisms can be found everywhere • Microorganisms have vast impact on the environment, the ecosystem, and human life (give examples) • Our current understanding of microbiology is the result of the work of thousands of microbiologists over hundreds of years • The advent of the microscope is what really began the study of microbiology • The Golden Era of Microbiology resulted in huge advancements in this field • Great achievements are still being reached today
  24. Suggested Reading • Chapter 4: Prokarytoic cells