Microbiology

1. Microbiology Chapter 1

2. Part I Introduction to Microbiology

3. Scope of Microbiology • Microbes • Life forms which require magnification for viewing • Ubiquitous • Each group has a distinct set of biological characteristics • Single celled vs. multi-celled • Prokaryotic vs. eukaryotic • Cell wall vs. no cell wall • Autotrophic vs. heterotrophic • Cellular vs. acellular

4. Prokaryotic vs. Eukaryotic

5. Assigning Characteristics • Bacteria • Protozoa • Fungi • Algae • Helminths • Viruses Assign common characteristics to each group

6. Mycobacterium tuberculosis. Acid fast bacteria (shown in pink) like this causes TB and leprosy. Light blue is Staph epi, a common bacteria cocci which inhabits the Skin. Not a common pathogen Schistosoma (worms) at two different stages of development – liver Disease and other symptoms (Top) Coccidioidomycosis Arthrospores (Bottom) Development of Arthrospores Into spherule in lung tissue Fungal Infection of the lung Staphylococcus Aureus Gram positive bacteria Staph infections and MRSA Trypanosoma Eukaryotic pathogen African Sleeping Sickness Treponema pallidum Bacterial spirochete Causes syphilis Herpes Virus

7. Size Comparisons

9. Part II Historical Figures in Microbiology

10. Superstition of Microbiology • Spontaneous generation • For thousands of years people believed that living things arose from vital forces present in non living matter • Mushrooms appearing on rotting wood • Afflicted people were thought to be cursed • Controversy between… • Abiogenesis and biogenesis

11. First Look at Microbes • In the 1600s • Robert Hooke (English) reported that living things were composed of little boxes or cells • Antonie van Leeuwenhoek construction microscopes which could magnify 300X • Described microorganisms that he observed in teeth scrapings & rain water

12. Abiogenesis vs. Biogenesis • Franceso Redi • He wanted to ascertain whether maggots arose from some “vital force” of the meat or were offspring of flies

13. Abiogenesis vs. Biogenesis • Conclusions of Redi’s Experiment • This and related experiments proved that complex animals such as insects and mice develop through biogenesis • However, meat leaf out but covered with gauze would still rot • Therefore, the idea that simpler organism could arise from abiogenesis was still accepted

14. Proving that Microbes Are Present in Dust Particles • Jablot’s vs. Needham’s Experiment • Jablots experiment supported the idea that microbes are present in the air

15. Proving that Microbes Are Present in Dust Particles • However, support for Jablot’s experiment faltered when Needham’s results were reported • Needham performed the same experiment with mutton gravy • Microbial growth was in both containers • What do you think happened here?

16. Proving that Microbes Are Present in Dust Particles • These disputes would be put to rest with Louis Pasteur’s work

17. Pasteurization • Pasteur also demonstrated that 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

18. Lister’s Work • English physician advanced the idea of antisepsis in health care setting 1860’s • Dressed wounds with carbolic acid (phenol) • Reduced deaths among patients by 2/3 • Listerine Mouthwash

19. Koch’s Postulates • 1876 Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, postulates, used to prove that a specific microbe causes a specific disease • Koch was a physician and Pasteur’s young rival

20. Koch’s Postulates Take scraping and plate on agar Mouse dies with sores A heterogeneous population of bacteria Grow – which one is the causative agent Isolate all different strains and types and inject into healthy mice and see which mice develop similar phenotype and symptoms Take a sample again from mice which died of same symptoms and isolate the causative agent again

21. Koch’s Postulates A sequence of experimental steps to relate a specific microbe to a specific disease

22. Koch’s Postulates Used to prove the specific causative agent of an infectious disease

23. Jenner’s Work • Observed that milkmaids did not acquire smallpox • Milkmaids were exposed to chronic low doses of cowpox and therefore acquired specific immunity • 1796 Jenner inoculated a person with cowpox virus and found this person was then protected against acquiring small pox • This protection is known as immunity • Called vaccinatin from vacca for cow

24. Alexander Fleming’s Work • In 1928 Fleming discovered the first antibiotic by accident • He observed that Penicillium fungus secreted a substance which killed bacteria • Explain why a fungus would do this • In 1940s penicillin was tested clinically and mass produced

25. Germ Theory of Disease • All of these aforementioned people and others helped give rise to the germ theory of disease • Germ Theory states that microorganisms can invade other organisms and cause disease • Before this many time politics and religion would spur on erroneous theories

26. Part III Introduction to Disease

27. Chronic vs. Infectious Disease • Chronic • Disease which persists over a long period of time • Atherosclerosis, cancer & heart failure • Infectious • Organism enters and tissues & grows • Bacterial – Prokaryotic • Viral – Acellular • Protozoan – Eukaryotic • Causes symptoms in patients

28. Conquering Infectious Disease • The triumph over infectious disease? • Antibiotics discovered in 1940s • Vaccinations routinely delivered in the 1950s through today • Eradication of polio and small pox • But then… • MRSA • Drug resistant TB • HIV • Ebola • Avia Flu • And more

29. Conquering Infectious Disease • What went wrong? • Medical advances • Older and sicker people live longer • More susceptible to garden variety microbes • Population is more mobile • Emerging diseases • Encroachment of humans into wild habitat • Rapid evolution and biochemical changes to microbes • Microbes have a quick generation time

31. Top Causes of Death * Stands for lower respiratory disease Infectious Diseases are shown in red

32. Infectious Disease Statistics

33. Part IV Taxonomy & Biological Classification

34. Organizing Life • Classification • Orderly arrangement of organisms into groups that indicate evolutionary relationships • Nomenclature • Assigning names to various taxonomic rankings • Identification • Correct placement of organism into taxonomic scheme

35. Taxonomy • Origins of organizing biological life • Carl von Linne or Linnaeus 1701 – 1778 • System of recognizing and defining properties of living organism followed by the placement into specific slots • Grouped according to similar properties • Grouped according to evolutionary relatedness • Constantly being revised and refined

36. Taxonomy

37. Nomenclature • Scientists use a standard binomial system • Overseen by an international group • Verify that standard procedures were followed • Ascertain the uniqueness of each name • Make sure no other name exists

38. Nomenclature • Staphylococcus aureus • Staphule – bunch of grapes • Aureus – golden • Campylobacter jejuni • Kampylos – curved • Bakterion – little rod • Jejunum – section of small intestine • Giardia lamblia • Alfred Giard – French microbiologist • Vilem Lambl – Bohemian physician

39. Evolution & Phylogeny • Evolution • All new species originate from preexisting species • Closely related organism have similar feature due to evolution from common ancestral forms • Phylogeny • Tree of life • Classification based on evolutionary relatedness

40. Whittaker’s System

41. Whittaker’s System • Although used for many years this system has problems in terms of evolutionary relatedness • Kingdom Protista • Autotrophs & heterotrops are groups together • Archaea • Although these organisms are prokaryotic they are more closely related to eukaryotic cells

42. Solution to Whittaker’s Tree • Biologist no longer group organisms into a 5 kingdom system • Currently a three domain system • Many original kingdoms still work • Plants, animals, fungi • However, Kingdom Protista & Kingdom Monera have been extensively reorganized into many different kingdoms

43. Three Domain System