BIOL 260-General Microbiology

1. BIOL 260-General Microbiology Instructor: Christopher Thor Masters Degree, Bioengineering Bachelors Degree, Molecular Biology

2. Welcome to BIOL 260: Microbiology! • First day: • Review of Syllabus • Sign-in • Introduce the course, review course expectations • Begin with first lab • Exercise 3: Microscope Lab

3. Objectives for today • Define prokaryotes, eukaryotes & their classification • Give a historical perspective on medical bacteriology • Introduction to bacterial stains and images

4. What is microbiology? • The scientific discipline which studies microbes or microorganisms • Biology of microbes • The interaction of microbes with other microbes, the environment, and humans

5. The “Yotes” Definitions: Prokaryote: Single celled organism, no nucleus. Bacteria, Archaea Eukaryote: Single or multi-celled organism, membrane bound nucleus Algae, Protozoa, Fungi, people

6. What are examples of microbes? • Algae • Fungi • Protozoa • Bacteria • Viruses Which are Prokaryotes are which are Eukaryotes?

7. Hierarchy

8. Types of Microbes: Algae

9. Types of Microbes: Protozoa

10. Types of Microbes: Fungi

11. Types of Microbes: Bacteria

12. Viruses, Viroids, Prions

13. Microorganisms are associated with • Disease • Cause of many epidemics in history • Bubonic plague (1346-1350) • Killed 25 million people • Small pox • Killed estimated 600 million people since 10,000 BC • Eradicated in 1979 • HIV • 3.1 million estimated new cases per year • 5% of Sub-Saharan Population • Malaria Small Pox

14. Bacteria are associated with • Normal microbiota (normal flora) • The bacteria that are present on our bodies

15. Bacteria are associated with • The environment • Rhizobium (the greatest bacteria you’ve never heard of) • Nitrogen fixation in the soil • Food products • Beer! Or bread, wine, sauerkraut, yogurt, cheese… • Medicines • Bacteria are “programmed” to make insulin

16. It all started with the microscope! Zacharis Janssen (1600) Antoni van Leewenhoek (1632-1723) Robert Hooke (1665) History of Microbiology

17. Zacharis Janssen’s microscope • Modeled after the telescope • Consisted of two lenses • Magnified images 3-10X

18. Leewenhoek’s microscope 20-30x magnification

19. Where do cells come from? • Spontaneous generation • Francesco Redi (1668) • Spontaneous Generation does not occur • John Needham (1745) • Spontaneous Generation does occur • Lazzaro Spallanzani (1765) • Louis Pasteur (1861) • Biogenesis • Rudolf Virchow (1858) • Living things come from living things

20. Pasteur’s flasks

21. John Tyndall questions Pasteur’s experiments • Could not reproduce Pasteur’s results • Specific growth media required • Found that there were heat resistant forms of microbes • Same year (1876) Ferdinand Cohn discovers heat resistant forms of bacteria called endospores • Spores can survive in space (Apollo Program, 1960s) • 1877 Robert Koch demonstrates that anthrax caused by Bacillus anthracis

22. Major Milestones in Microbiology

23. Major Milestones in Microbiology

24. New cells need to be placed in categories • Aristotle-plant or animal kingdom • Kingdom Protista (1866) • Electron microscope (1940’s) • Kingdom Procaryotae (1968) • Carl Woese proposed 3 Domains (1978)

25. Three Domain System

26. Prokaryotes (Single Celled) • Bacteria Domain (Eubacteria) • Peptidoglycan cell walls • Gram negative • Gram positive • Archaea Domain (Archaebacteria) • Not a peptidoglycan cell wall • Extremophiles • Methanogens • Halophiles • Thermophiles

27. Binomial system of nomenclature • Genus and species • Escherichia coli, Escherichiacoli • E. coli is not acceptable on exams or unknowns… • Both names are in italics or underlined and correctly spelled.

28. Relationship of size and resolution

29. Types of microscopes • Brightfield • Darkfield • Phase Contrast • Fluorescent • Electron

30. Microscopy-Brightfield

31. Oil has same refractive index as glass

32. Stained specimen Microscopy, Oil Immersion Wet mount

33. Microscopy Electron microscopes - maximum magnification 100,000X

34. Microscopy Electron microscopes - maximum magnification 100,000X “Color-enhanced”

35. Relative sizes Figure: CNX.org

36. Staining: key to visualization • Simple • Differential • Special

37. Microscopic Techniques: Dyes and Staining • Simple stains • Stains everything • Differential stains • Stain based on cellular traits Gram stain - separates bacteria into two categories based on type of cell wall Acid Fast Stain – Stains non-peptidoglycan containing bacteria (Mycobacteria) Gram-positive Gram-negative

38. Microscopic Techniques: Dyes and Staining • Simple stains • Differential stains Gram stain - separates bacteria into two categories based on type of cell wall Purple: Bacteria with high peptidoglycan containing cell walls Pink: Counter stain

39. Differential Stain: Acid Fast

40. Microscopic Techniques: Dyes and Staining Fluorescent dyes and tags

41. Special stain: Capsule Stain

42. Special stain: Endospore Stain

43. Special stain: Flagella Stain

44. Morphology of Prokaryotic Cells: Cell Shapes

45. Morphology of Prokaryotic Cells: Cell Shapes

46. Morphology of Prokaryotic Cells: Cell Groupings

47. Morphology of Prokaryotic Cells: Multicellular Associations Biofilm containing mixed species