2. Introduction What are microbes? Where can they be found? How big are they?

3. Fig. 1.7

4. Types of Microbes They include – Bacteria – Protozoa – Fungi – Algae – *Helminths – *Viruses – *Prions

5. Bacteria Unicellular Prokaryotic Cell walls contain peptidoglycan Have many shapes Generally reproduce by binary fission Obtain nourishment from organic or inorganic substances of photosynthesis

6. Archaea Prokaryotic cells Cell walls lack peptidoglycan (if present) Not known to cause human disease Mainly found in extreme environments

7. Fungi Eukaryotes May be multicellular or unicellular May reproduce sexually or asexually Obtain nourishment by absorbing organic material from their environments Cell walls composed of chitin

8. Protozoa Eukaryotes Unicellular Classified by type of movement May live as free entities or parasites May reproduce sexually or asexually

9. Algae Photosynthetic eukaryotes May produce sexually or asexually May be unicellular or multicellular Cell walls composed of cellulose

10. Helminths Multicellular animal parasites

11. Viruses Acellular organisms Composed mainly of protein and nucleic acid; may contain lipids Obligate intracellular parasites

12. Prions Proteinaceous infectious particles Composed of protein

15. 6 processes that define life 1. growth 2. reproduction & heredity 3. metabolism 4. movement and/or irritability 5. capacity to transport substances into & out of cell 6. cell support, protection & storage mechanisms

16. History of Microbiology Supernatural Miasma theory- disease is caused by an altered chemical in the air Zaccharias Jansen created the first microscope (1600). No technology prior to this

17. Modification of Microbe Definition Thiomargarita nambiensis- large enough to be seen without a microscope Viruses and prions- not living organisms

18. Microbes are easier to study Microorganisms are easier to study than macroorganisms (organisms visible with the naked eye) because of – Relative simplicity – Rapid reproduction – Adapatility

19. History of Microbiology Antoni van Leeuwenhoek- discovered “animalcules” Robert Hooke- (1678)- developed the compound microscope; confirmed Leeuwenhoek’s findings; marked the beginning of the cell theory

20. Spontaneous Generation Spontaneous generation- theory that living things arise from nonliving things Debate of this theory

21. Francesco Redi In his experiment, he used 3 jars containing meat and left the jar open. He took 3 other jars containing meat and sealed them. Days later, only the open jar contained organisms. Opponents said sealing the jar prevented fresh air to enter, therefore, microbes could not grow. He modified his experiment using a mesh gauze, which was thin enough to allow air, but prevent microbes.

22. Fig. 1.p010

23. John Needham Boiled nutrient broth and placed them into sealed containers. Days later, microbes grew. What are some reasons this may have happened?

24. Lazarro Spallanzani In his experiment, he sealed flasks of nutrient broth then boiled them. He transferred the broth into sealed containers and no microbes grew. Needham suggested the “vital force” needed for microbes to grow was kept out of the flask by the seals

25. Laurent Lavosier Showed importance of oxygen to life. Spallanzani opponents claimed there wasn’t enough oxygen to support life in his sealed flasks

26. Shultz and Schwann Thought air was the source of microbes. The passed air through chemicals into heat treated flasks. No microbes grew. Opponents said the chemicals prevented microbial growth

28. Louis Pasteur Louis Pasteur resolved the debate of spontaneous generation. He set up flasks with beef broth, boiled them and left them open. Other flasks containing boiled beef broth were sealed. A few days later, microbes were present in the open flasks, but not the sealed ones. Pasteur suggested that microbes are present in the air and are capable of contaminating non living solutions. Then, he set up another series of flasks with boiled beef broth containing an S shaped opening. A few days later, no microbes were present.

29. Louis Pasteur These S shaped flasks allowed air to enter (filling the oxygen requirement), but prevented microbes from entering (they are presumably “caught” in the S shaped openings). He showed microbes are present in air and can contaminate sterile solutions, but the air itself does not create microbes. He also showed these microbes can be destroyed by heat or microbial access can be blocked. These discoveries formed the basis of aseptic techniques- techniques used to prevent microbial contamination

30. Louis Pasteur Showed microbes caused fermentation & spoilage Disproved spontaneous generation of m.o. Developed aseptic techniques. Developed a rabies vaccine. (1822-1895)

31. The Golden Age of Microbiology (1857-1914) During this time rapid advances in microbiology were made and spearheaded by Pasteur and Robert Koch Were possible due to advances in microscopy and other technology of the Industrial Revolution

32. Germ Theory of Disease Many diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc.

33. Aseptic Techniques Ignaz Semmelweis showed that physicians who do not disinfect their hands can transmit disease to patients. Joseph Lister began using phenol as a disinfectant. The number of deaths from childbirth fever decreased.

34. Robert Koch Robert Koch (1876) set out to discover the causative agent of anthrax. He took a sample of blood from cattle that died of anthrax and cultured it. Samples from the culture were then injected into healthy animals. After these animals became sick and died, he isolated the bacteria in their blood and cultured it. He found that both sets of organisms were identical. This experiment established a sequence of steps for relating a specific organism to a specific disease. These steps are known as Koch’s postulates

35. Koch’s Postulates 1) the same pathogen must be present in every case of disease 2) pathogen must be isolated from diseased host and grown in pure culture 3) pathogen from pure culture must cause disease when inoculated into a healthy susceptible laboratory animal 4) pathogen must be isolated from inoculated animal and must be shown to be the original organism

36. Robert Koch Established a sequence of experimental steps to show that a specific m.o. causes a particular disease. Developed pure culture methods. Identified cause of anthrax, TB, & cholera. (1843-1910)

37. Edward Jenner Edward Jenner (1796) discovered from milkmaids that those who contracted cowpox became mildly ill, but never contracted smallpox. Jenner decided to determine the validity. He obtained permission to use an 8 year old “volunteer” and inoculated him with scrapings from cowpox pustules. The child became ill, but never got smallpox. This process was termed vaccination. Protection from the disease or recovery from the disease is called immunity.

38. Louis Pasteur Pasteur (1880) found that aged microbes also confer immunity. He was working on isolating the causative agent of cholera using chickens. He inoculated chickens with cholera and they became sick and died. Allegedly, he went away for the summer, and his cholera samples aged. When he came back, he used these aged cultures to inoculate the chickens. These chickens became mildly ill but did not die. Then (allegedly) he inoculated these same chickens with a regular strength batch since he ran out of new chickens. He found that these chickens did not get sick at all. He determined these aged cultures lost the ability to cause disease and was able to confer immunity.

39. Magic Bullet Paul Ehrlich (1910) speculated about a “magic bullet”, a chemical which could destroy a pathogen without affecting the host. Prior to this, the only chemical being used was quinine, to treat malaria. Ehrlich eventually discovered salvarsan, effective against syphilis.

40. Alexander Fleming (1928), while doing experiments, left a Petri dish which became contaminated by mold. He noted an area of inhibition around the mold, an area where no bacterial growth occurred. However, the usefulness of this mold, used to produce penicillin, did not occur until the 1940s.

41. Types of Study Bacteriology- study of bacteria Mycology- study of fungi Parasitology- study of parasites Immunology- study of the immune system Virology- study of viruses Phycology (algology)- study of algae Protozoology- study of protozoa

42. Benefits of Microbes Recycle vital elements Recycle water Bioremediation Pest control Food

43. Emerging Infectious Disease EID’s may occur due to: – evolutionary changes to existing organisms – spread of diseases to new geographic regions – increased human exposure to new diseases in areas undergoing ecological change (construction, deforestations) – increased number of patients with depressed immune systems – disruptions in human population, such as crowding or immigration – lack of immunization – lack of nourishment – mass production and packaging of food – animal migration

44. People Involved in Classification Charles Darwin (1859) proposed the theory of natural selection Carolus Linnaeus (1735-1759)- divided organisms into plant and animal and created a 2 name system Carl von Nageli (1857)- proposed bacteria and fungi be placed into the plant kingdom Ernst Haeckel (1866)- proposed kingdom Protista to include bacteria, protozoa, algae and fungi; Fungi were placed into their own kingdom in 1959 Robert G. E. Murray (1968)- proposed the kingdom Prokaryotae

45. Evolution- living things change gradually over millions of years Changes favoring survival are retained & less beneficial changes are lost. All new species originate from preexisting species. Closely related organism have similar features because they evolved from common ancestral forms. Evolution usually progresses toward greater complexity.

46. Naming micoorganisms Binomial (scientific) nomenclature Gives each microbe 2 names – Genus - noun, always capitalized – species - adjective, lowercase Both italicized or underlined – Staphylococcus aureus (S. aureus) – Bacillus subtilis(B. subtilis) – Escherichia coli(E. coli)

47. More Classification Robert Whittaker (1969)- proposed a 5 kingdom system – Monera (Prokaryotae)- bacteria – Protista-protozoa and algae – Fungi-yeasts, molds – Plantae-plants – Animalia-vertebrates, invertebrates Carl R. Woese (1978) proposed 3 domains to be placed above kingdom

49. Fig. 1.15

50. Taxonomy - system for organizing, classifying & naming living things Domain - Archaea, Bacteria & Eukarya Kingdom - 5 Phylum or Division Class Order Family Genus species

52. 3 domains Eubacteria -true bacteria, peptidoglycan Archaea –odd bacteria that live in extreme environments, high salt, heat, etc Eukarya- have a nucleus, & organelles

53. Methods of Classifying and Identifying Microbes Chapter 4 pgs 107-108 Bergey’s Manual of Determinative Bacteriology Morphological Characteristics Differential Staining Biochemical Tests Serology DNA base composition Using rRNA sequencing,

54. Scientific Method Form a hypothesis - a tentative explanation that can be supported or refuted by observation & experimentation A lengthy process of experimentation, analysis & testing either supports or refutes the hypothesis. Results must be published & repeated by other investigators.

55. Scientific Method If hypothesis is supported by a growing body of evidence & survives rigorous scrutiny, it moves to the next level of confidence - it becomes a theory Evidence of a theory is so compelling that the next level of confidence is reached - it becomes a Law or principle

58. Fig. 1.11