1. SCOPE AND HISTORY OF MICROBIOLOGY
CHAPTER 1
Photo courtesy Kenneth Ingham

2. Why Study Microbiology?
Ubiquity
Courtesy Jacquelyn G. Black

3. Microbes in Our Lives
Microorganisms are organisms that are too small to be seen with the unaided eye.
“Germ” refers to a rapidly growing cell.

4. Why Study Microbiology?
Biological roles- decomposers, recyclers, symbionts
Animal digestion - ruminants, methane
Food Microbiology - yogurt, sauerkraut, Kim Chee, cheese, beer, bread etc.
Food safety - prevent putrefication, disease etc.

5. Why Study Microbiology?
Pharmaceuticals- produce complex drug molecules. (ex. insulin )
Bioremediation - using microbes to clean pollution
Pathogenicity - bacteria and viruses that make us sick
Fundamental Biology most biochemical pathways worked out with microbes

6. Microbes in Research Simple structure- many are prokaryotic
Large populations - up to billions/ml
Rapid growth rates
Vibrio harveyii = fastest grower known
1 gen/15 mins

7. Scale of Microbes

8. Classification of Microorganisms
Three domains
Bacteria
Archaea
Eukarya
Protists
Fungi
Plants
Animals

9. Microbe Types Bacteria prokaryotes Eubacteria Archaebacteria
CNRI/ Photo Researchers, Inc.

10. Bacteria Prokaryotes Peptidoglycan cell walls Binary fission
For energy, use organic chemicals, inorganic chemicals, or photosynthesis
Figure 1.1a

11. Archaea: Prokaryotic Lack peptidoglycan Live in extreme environments
Include:
Methanogens
Extreme halophiles
Extreme thermophiles
Figure 4.5b

12. Microbe Types Algae Fungi Protista, Planta Eukaryotes
R. B. Taylor/Photo Researchers, Inc.

13. Algae Eukaryotes Cellulose cell walls Use photosynthesis for energy
Produce molecular oxygen and organic compounds
Volvox
Figure 1.1d

14. Fungi Eukaryotes Chitin cell walls Use organic chemicals for energy
Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae
Yeasts are unicellular
Figure 1.1b

15. Microbe Types
Viruses
Living?
Thomas Broker/Phototake

16. Microbe Types
Protozoa
eukaryotes
Michael Abbey/Visuals Unlimited

17. Protozoa Eukaryotes Absorb or ingest organic chemicals
May be motile via pseudopods, cilia, or flagella
Amoeba
Figure 1.1c

18. Microbe Types Helminths/Arthropods Eukaryotes (multicellular)
Cath Ellis/Photo Researchers, Inc.

19. Multicellular Animal Parasites
Eukaryote
Multicellular animals
Parasitic flatworms and round worms are called helminths.
Microscopic stages in life cycles.
tapeworm
Figure 12.28

20. Microorganisms:
Figure 1.1

21. Roles of Microbiologists
Biological
Pharmaceutical/Vaccines
Agricultural- Rumen microbiology

22. Microbiology Settings
Universities
Commercial laboratories
food prep & cosmetics
Courtesy United States Department of Agriculture

23. Microbiology Settings
Legal
Clinical
Courtesy United States Department of Agriculture

24. Microbiology Settings
Public Health
Epidemiology

25. Microbiology History Plagues in History
Pieter Brueghel the Elder (1528–1569), Flemish, Trionfolo della Morte, Painting, Prado, Madrid, Spain/Scala/Art Resource, NY

26. The Black Plaque-Bubonic plaque
1348 and 1350
( )
Killed 75 million people worldwide
Yersinia pestis
Flea vector.

27. Smallpox
(430 BC? ):
Killed more than 300 million people worldwide in the 20th century alone, and most of the native inhabitants of the Americas.
Smallpox (also known by the Latin names Variola or Variola vera) is a contagious disease unique to humans. Smallpox is caused by either of two virus variants named Variola major and Variola minor. The deadlier form, V. major, has a mortality rate of 30–35%, while V. minor causes a milder form of disease called alastrim and kills ~1% of its victims. Long-term side-effects for survivors include the characteristic skin scars. Occasional side effects include blindness due to corneal ulcerations and infertility in male survivors.
Smallpox killed an estimated 60 million Europeans, including five reigning European monarchs, in the 18th century alone. Up to 30% of those infected, including 80% of the children under 5 years of age, died from the disease, and one third of the survivors became blind.

28. Microbiology History Early Studies Hooke Cork Slices- 1st Scope (cell)
Van Leeuwenhoek microscope
Linnaeus classification
Schwann cell theory
© Corbis

29. Fig. 1-9

30. Fig. 1-10

31. Germ Theory vs. Spontaneous Generation
Redi maggots
Spallanzani - boiling

32. Germ Theory vs. Spontaneous Generation
Pasteur
© Charles O’Rear/Corbis

33. Understanding Disease
Robert Koch
Koch’s postulates
Lister/
Semmelweiss
Granger Collection
disinfection
handwashing

34. Koch’s postulates
1. The suspected causal organism must be constantly associated with the disease.
2. The suspected causal organism must be isolated from an infected plant (or animals)
and grown in pure culture.
3. When a healthy susceptible host is inoculated with the pathogen from pure culture,
symptoms of the original disease must develop.
4. The same pathogen must be re-isolated from plants (animals) infected under experimental
conditions.

35. Special Fields of Study
Immunology
Virology
Immune system and it’s interaction with microbes
Study of very small ?living? Viral particles

36. Special Fields of Study
Chemotherapy
Antibiotics
Synthetics
Natural products
penicillin
© UPI/Bettmann/Corbis
Man-made
Erhlich
Alexander Fleming
Penicillin
doxycycline

37. Special fields of Study
Genetics/Molecular Biology
genes and how they are expressed
Recombinant DNA technology
Genomics decyphering genomes and expression
Proteomics decyphering protein structure/function

38. Microbes I know and Love?
Bacillus megaterium
Klebsiella aerogenes
Escherichia coli
Klebsiella pneumoniae
Mycobacterium smegmatis
Mycobacterium marinum

39. A Brief History of Microbiology
Ancestors of bacteria were the first life on Earth.
The first microbes were observed in 1673.

40. The First Observations
In 1665, Robert Hooke reported that living things were composed of little boxes or cells.
In 1858, Rudolf Virchow said cells arise from preexisting cells.
Cell Theory. All living things are composed of cells and come from preexisting cells

41. The Golden Age of Microbiology
Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

42. Fermentation and Pasteurization
Pasteur showed that microbes are responsible for 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).

43. Fermentation and Pasteurization
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.
Figure 1.4

44. 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 Semmelweiss advocated handwashing to prevent transmission of puerperal fever from one OB patient to another.

45. 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.
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.

46. Vaccination
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

47. The Birth of Modern Chemotherapy
Treatment with chemicals is chemotherapy.
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.
1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis.
1930s: Sulfonamides were synthesized.

48. The Birth of Modern Chemotherapy
1928: Alexander Fleming discovered the first antibiotic.
He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus.
1940s: Penicillin was tested clinically and mass produced.
Figure 1.5

49. Modern Developments in Microbiology
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.

50. Modern Developments in Microbiology
Immunology is the study of immunity. Vaccines and interferons are being investigated to prevent and cure viral diseases.
The use of immunology to identify some bacteria according to serotypes (variants within a species) was proposed by Rebecca Lancefield in 1933.

51. Modern Developments in Microbiology
Virology is the study of viruses.
Recombinant DNA is DNA made from two different sources. In the 1960s, Paul Berg inserted animal DNA into bacterial DNA and the bacteria produced an animal protein.
Recombinant DNA technology or genetic engineering involves microbial genetics and molecular biology.

52. Modern Developments in Microbiology
Using microbes
George Beadle and Edward Tatum showed that genes encode a cell’s enzymes (1942)
Oswald Avery, Colin MacLeod, and Maclyn McCarty showed that DNA was the hereditary material (1944).
Francois Jacob and Jacques Monod discovered the role of mRNA in protein synthesis (1961).

53. Selected Novel Prizes in Physiology or Medicine
1901* von Behring Diphtheria antitoxin
1902 Ross Malaria transmission
1905 Koch TB bacterium
1908 Metchnikoff Phagocytes
1945 Fleming, Chain, Florey Penicillin
1952 Waksman Streptomycin
1969 Delbrück, Hershey, Luria Viral replication
1987 Tonegawa Antibody genetics
1997 Prusiner Prions
* The first Nobel Prize in Physiology or Medicine.