Introduction to microbiology

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Introduction to microbiology

  1. 1. Welcome to Microbiology 1 For Today… Introduction to the course Explore the history and foundation of microbiology Dimensional Analysis
  2. 2. Chapter 1 The Microbial World and You
  3. 3. Chapter 1 The Microbial World and You What is Microbiology? Microbes, or microorganisms are minute living things that are usually unable to be viewed with the naked eye. What are some examples of microbes? Bacteria, fungi, protozoa, algae, viruses are examples! Some are pathogenic “Germ” refers to a rapidly growing cell.
  4. 4. Chapter 1 The Microbial World and You What is Microbiology? Microbes (benefits): Decompose organic waste Are producers in the ecosystem by photosynthesis Produce industrial chemicals such as ethyl alcohol and acetone Produce fermented foods such as vinegar, cheese, and bread
  5. 5. Chapter 1 The Microbial World and You What is Microbiology?
  6. 6. Chapter 1 The Microbial World and You What is Microbiology? Knowledge of Microbes allows humans to Prevent food spoilage Prevent disease occurrence Led to aseptic techniques to prevent contamination in medicine and in microbiology laboratories.
  7. 7. Chapter 1 The Microbial World and You History of Microbiology Ancestors of bacteria were the first life on Earth.
  8. 8. Chapter 1 The Microbial World and You History of Microbiology The first microbes were observed in 1673. In 1665, Robert Hooke (Englishman) reported that living things were composed of little boxes or cells.
  9. 9. Chapter 1 The Microbial World and You History of Microbiology 1673-1723, Antoni van Leeuwenhoek (Dutch) described live microorganisms that he observed in teeth scrapings, rain water, and peppercorn infusions.
  10. 10. Chapter 1 The Microbial World and You History of Microbiology Many believed spontaneous generation: life can arise from non-living matter In 1668, the Italian physician Francesco Redi performed an experiment to disprove spontaneous generation. Can you think of an experiment that could disprove spontaneous generation?
  11. 11. Chapter 1 The Microbial World and You History of Microbiology Conditions Results 3 jars covered with fine net No maggots 3 open jars Maggots appeared From where did the maggots come? What was the purpose of the sealed jars? Spontaneous generation or biogenesis? Redi filled six jars with decaying meat.
  12. 12. Redi placed meat in three containers. One was uncovered, a second was covered with paper, and the third was covered with fine gauze that would exclude flies. Flies laid their eggs on the uncovered meat and maggots developed. The other two pieces of meat did not produce maggots spontaneously. Chapter 1 The Microbial World and You
  13. 13. However, flies we attracted to the gauze-covered container and laid their eggs on the gauze; these eggs produced maggots. Thus the generation of maggots by decaying meat resulted from the presence of fly eggs, and meat did not spontaneously generate maggots. Chapter 1 The Microbial World and You
  14. 14. Chapter 1 The Microbial World and You History of Microbiology So now there are two hypotheses: The hypothesis that living organisms arise from nonliving matter is called spontaneous generation. According to spontaneous generation, a “vital force’ Forms life. The Alternative hypothesis, that the living organisms arise from preexisting life, is called biogenesis.
  15. 15. Chapter 1 The Microbial World and You History of Microbiology Rudolf Virchow (German) presented biogenesis: living cells can arise only from preexisting cells.
  16. 16. Read up on the historical contribution(s) of microbiology made by: John Needem (1713-1781) Lazzaro Spallanzani (1729-1799) Theodore Schwann (1810-1882) Theodorvon Dusch (1824-1890) Chapter 1 The Microbial World and You
  17. 17. Chapter 1 The Microbial World and You History of Microbiology 1861: Louis Pasteur demonstrated that microorganisms are present in the air. Conditions Results Nutrient broth placed in flask, heated, not sealed Microbial growth Nutrient broth placed in flask, heated, then sealed No microbial growth Spontaneous generation or biogenesis?
  18. 18. Pasteur experiment – Pasteur first filtered air through cotton and found that objects resembling plant spores had been trapped. If a piece of the cotton was placed in sterile medium after air had been filtered through it, microbial growth occurred. Next he placed nutrients solutions in flasks, heated their necks in a flame, and drew them out into a variety of curves. Chapter 1 The Microbial World and You
  19. 19. Cont’d The swan neck flasks that he produced in this way had necks open to the atmosphere. Pasteur then boiled the solutions for a few minutes and allowed them to cool. No growth took place even though the contents of the flasks were exposed to the air. Pasteur pointed out that no growth occurred because dust and germs had been trapped on the walls of the curved necks.
  20. 20. Cont’d If the neck were broken, growth commenced immediately.
  21. 21. Chapter 1 The Microbial World and You History of Microbiology Pasteur’s S-shaped flask kept microbes out but let air in. These experiments form the basis of aseptic technique
  22. 22. Chapter 1 The Microbial World and You History of Microbiology The Golden Age of Microbiology 1857-1914 Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, microbes and fermentation, immunity, and antimicrobial drugs
  23. 23. Chapter 1 The Microbial World and You History of Microbiology Pasteur showed that microbes are responsible for fermentation (Germ theory of fermentation). Fermentation is the conversation of sugar to alcohol to make beer and wine. Microbial growth is also responsible for spoilage of food. Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid).
  24. 24. Chapter 1 The Microbial World and You History of Microbiology Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time is called pasteurization.
  25. 25. Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease 1835: Agostino Bassi showed a silkworm disease was caused by a fungus. 1865: Pasteur believed that another silkworm disease was caused by a protozoan. 1840s: Ignaz Semmelwise advocated handwashing to prevent transmission of puerperal fever from one OB patient to another.
  26. 26. Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease • 1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteur’s work showing microbes are in the air, can spoil food, and cause animal diseases.
  27. 27. Chapter 1 The Microbial World and You History of Microbiology The Germ Theory of Disease 1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, used to prove that a specific microbe causes a specific disease. Koch was a physician and Pasteur’s young rival
  28. 28. Chapter 1 The Microbial World and You History of Microbiology Koch's Postulates are used to prove the cause of an infectious disease.
  29. 29. Chapter 1 The Microbial World and You History of Microbiology Koch's Postulates are a sequence of experimental steps to relate a specific microbe to a specific disease.
  30. 30. Chapter 1 The Microbial World and You History of Microbiology A young milkmaid informed the physician Edward Jenner that she could not get smallpox because she had already been sick from cowpox. 1796: Edward Jenner inoculated a person with cowpox virus. The person was then protected from smallpox. Called vaccination from vacca for cow The protection is called immunity
  31. 31. Chapter 1 The Microbial World and You History of Microbiology What can you say about the cowpox and smallpox viruses?
  32. 32. Chapter 1 The Microbial World and You History of Microbiology Vaccinations produced from avirulent microbial strains produced from live viruses produced from viral particles
  33. 33. Chapter 1 The Microbial World and You History of Microbiology Chemotherapy – treatment with chemicals • Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics. • Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes. • Quinine from tree bark was long used to treat malaria.
  34. 34. Chapter 1 The Microbial World and You History of Microbiology Chemotherapy – treatment with chemicals • 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. • 1930s: Sulfonamides were synthesized.
  35. 35. Chapter 1 The Microbial World and You History of Microbiology 1928: Alexander Fleming discovered the first antibiotic. He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus (bacteria). 1940s: Penicillin was tested clinically and mass produced.
  36. 36. Chapter 1 The Microbial World and You Modern Developments • Bacteriology is the study of bacteria. • Mycology is the study of fungi. • Parasitology is the study of protozoa and parasitic worms. • Recent advances in genomics, the study of an organism’s genes, have provided new tools for classifying microorganisms.
  37. 37. Read up on these branches of microbiology and their uses of microorganism, for example: Environmental Microbiology Industrial Microbiology Agricultural microbiology Chapter 1 The Microbial World and You
  38. 38. Scope of Microbiology Microorganisms are usually divided into six subgroups: Bacteria, archaea, alage, fungi, protozoa, and viruses. These subgroups are not close related. Bacteria are less like archaea or algae or fungi or protozoa or virus than a shark is like a giraffe or an orchid is like an eagle.
  39. 39. Scope of Microbiology These are grouped based on the techniques for identifying, cultivating and studying which are similar. Read up on primary distinction among sub groups. Example: prokaryotes and eukaryotes.
  40. 40. Chapter 1 The Microbial World and You Classification of Microbes Taxonomy • The science of classifying organisms • Provides universal names for organisms • Provides a reference for identifying organisms
  41. 41. Chapter 1 The Microbial World and You Classification of Microbes Taxonomy • Systematics or phylogeny • The study of the evolutionary history of organisms • All Species Inventory (2001-2025) • To identify all species of life on Earth
  42. 42. Chapter 1 The Microbial World and You Classification of Microbes Taxonomic Hierarchy Domain Kingdom Phylum Class Order Family Genus Species Dumb Kings Play Chess On Funny Green Square s
  43. 43. Chapter 1 The Microbial World and You Classification of Microbes Taxonomic Hierarchy Domain Kingdom Phylum Class Order Family Genus Species Binomal Nomenclature uses the Genus and Species name to identify each creature.
  44. 44. Chapter 1 The Microbial World and You Classification of Microbes Taxonomic Hierarchy Each name is Latinized There is a specific way to write each name. Homo sapiens The first word is capitalized Name is in italics Homo sapiens H. sapiens
  45. 45. Chapter 1 The Microbial World and You
  46. 46. Chapter 1 The Microbial World and You
  47. 47. Chapter 1 The Microbial World and You
  48. 48. Chapter 1 The Microbial World and You Bacteria (or Eubacteria) Most abundant on earth They are nitrogen fixers and recycle carbon No membrane bound organelles
  49. 49. Chapter 1 The Microbial World and You Archaea Methanogens Halophiles Hyperthermophiles
  50. 50. Chapter 1 The Microbial World and You Classification of Microbes
  51. 51. Chapter 1 The Microbial World and You •Eukaryotic species: •A group of closely related organisms that breed among themselves •Prokaryotic species: •A population of cells with similar characteristics •Clone: Population of cells derived from a single cell •Strain: Genetically different cells within a clone •Viral species: •Population of viruses with similar characteristics that occupies a particular ecological niche Classification of Microbes
  52. 52. Chapter 1 The Microbial World and You Classification of Microbes
  53. 53. Chapter 1 The Microbial World and You Let’s examine some microbes Paramecium caudatum Euglena acus Peridiniumis - a dinoflagellate Classification of Microbes
  54. 54. Chapter 1 The Microbial World and You Microbes and Human Disease • Bacteria were once classified as plants which gave rise to use of the term flora for microbes. • This term has been replaced by microbiota. • Microbes normally present in and on the human body are called normal microbiota.
  55. 55. Chapter 1 The Microbial World and You Microbes and Human Disease • Normal microbiota prevent growth of pathogens. • Normal microbiota produce growth factors such as folic acid and vitamin K. • Resistance is the ability of the body to ward off disease. • Resistance factors include skin, stomach acid, and antimicrobial chemicals.
  56. 56. Chapter 1 The Microbial World and You Microbes and Human Disease • When a pathogen overcomes the host’s resistance, disease results. • Emerging Infectious Diseases (EID): New diseases and diseases increasing in incidence
  57. 57. Chapter 1 The Microbial World and You Major Taxonomic Groups of Bacteria per Bergey’s manual Gracilicutes – gram-negative cell walls, thin- skinned Firmicutes – gram-positive cell walls, thick skinned Tenericutes – lack a cell wall & are soft Mendosicutes – archaea, primitive procaryotes with unusual cell walls & nutritional habits
  58. 58. species –a collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly strain or variety – a culture derived from a single parent that differs in structure or metabolism from other cultures of that species (biovars, morphovars) type – a subspecies that can show differences in antigenic makeup (serotype or serovar), susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype).
  59. 59. species –a collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly strain or variety – a culture derived from a single parent that differs in structure or metabolism from other cultures of that species (biovars, morphovars) type – a subspecies that can show differences in antigenic makeup (serotype or serovar), susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype).

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