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MICROBIOLOGY

MICROBIOLOGY

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MICROBIOLOGY

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  1. MICROBIOLOGY Introduction & Classification

  2. Topics • Classification • Methods of Microbiology • Nutrition & Growth • Microbial Structure • Metabolism • Host parasite relationships • Control of Growth

  3. Types of Microorganisms • Bacteria • Gram positive & gram negative • Viruses • RNA & DNA • Fungi • Yeasts & molds • Protozoa

  4. History • Robert Hooke • Described units in cork as cells Anton van Leeuwenhoek-1667 • Made lenses or simple microscopes

  5. Spontaneous Generation • Abiogenesis-living matter arising from nonliving matter • Redi –maggots & meat • Pasteur et al disproved abiogenesis

  6. Pasteur • Fermentation • Yeast ferment grape juice –alcohol • Bacteria ferment grape juice-acids • Pasteurization

  7. Germ Theory of Disease • Koch • Koch’s postulates • Developed pure culture techniques • Discovered TB agent

  8. Immunology/Chemotherapy • Jenner and smallpox vaccine • Used cowpox virus

  9. Antiseptics • Semmelweis • Lister

  10. Fleming • Discovered penicillin

  11. Taxonomy • System of cataloging organisms • Identification: characterization of organisms • Classification: arrangement of organisms into similar groups • Nomenclature: assign names

  12. Binominal Nomenclature • Genus-capitalized ; collection of species • Microbes – species can be subdivided into strains • Strains have small genetic differences

  13. Rules • Both genus & species underlined or italicized • Strain-subdivision of species • ID by name, number or letter • Example- Escherichia coli- E. coli K12

  14. Classification • Wittaker-5 kingdoms • Plants • Animals • Fungi • Protista • Monera or Prokaryote

  15. Domains • Carl Woese-1980s • Based upon modern techniques • Sequence of rRNA in ribosomes • Three cell types based upon ribosomes

  16. Three Domains • Domains above kingdom level • Bacteria or Eubacteriae • Prokaryotes with peptidoglycan in cell wall • Divide by binary fission • Motile by flagella or cilia • Sensitive to antibiotics

  17. Archaea • Ancient prokaryotes • Cell wall present, not peptidoglycan • Live in extreme environments • Have unusual metabolic processes • Not sensitive to antibiotics

  18. Archaea • Methanogens -strict anaerobes • Produce methane from CO2 + H2 • Live in anaerobic mud lakes • Intestine of cows

  19. Archaea • Halophiles • Require high concentration of salt • Maintain cell wall • Spoilage of food-salted fish • Salt lakes

  20. Archaea • Thermophiles • Live in hot sulfurous waters or acidic water • Nucleic acids/proteins do not function at low temperatures • Volcanic vents in ocean

  21. Eukarya • All eukaryotes • Cell wall varies in composition • Not sensitive to antibiotics • Fungi-yeasts and molds • Protists-slime molds, protozoa, & algae • Plants & animals

  22. Endosymbiotic Theory • Eukaryotes evolved from prokaryotes • Supported by similarities between prokaryotes & organelles in eukaryotes • Mitochondria & chloroplasts same size as prokaryote cell • Contain DNA, 70S ribosomes • Endosymbiont-organism that lives within another

  23. Support for Theory • Prokary Eukary Mitoch & Chloro • DNA circular linear circular • Histones No Yes No • Ribosomes 70S 80S 70S • Growth binary mitosis binary • Cyanophora

  24. Viruses • Obligate intracellular parasites • Not cells so non living agent • No ribosomes • Classification is different

  25. Viroids & Prions • Viroids • Single short piece of RNA • Cause disease in plants • ? In humans • Prions • Protein • Cause neurodegenerate diseases • Humans & animals • CJD & mad cow

  26. New Challenges • Antibiotic resistance • MRSA, VRE & ESBL • Emerging diseases • SARS & Avian Influenza • Bioterrorism • Anthrax, smallpox, plague, botulism