01. Introduction to Microbiology, first session
- 2. 2 2 MICROBIOLOGY MICROBIOLOGY • The study of organisms too small to be seen without magnification – bacteria – viruses – fungi – protozoa – helminths (worms) – algae – some multicellular parasites
- 3. 3 3 Introduction cont Introduction cont • Two basic themes 1.Basic science of understanding life 2.The application of science to human needs
- 4. 4 4 BRANCHES OF STUDY WITHIN BRANCHES OF STUDY WITHIN MICROBIOLOGY MICROBIOLOGY 1.Immunology 2.Public health microbiology & epidemiology 3.Food, dairy and aquatic microbiology 4.Biotechnology 5.Genetic engineering & recombinant DNA technology
- 5. 5 5 Importance of Microorganisms Importance of Microorganisms 1.Oldest form of life 2.Existed on earth for billions of years before plant and animals. 3.Have great biomass 4.Microorganisms have killed more people than have ever been killed in war. 5.Without certain microorganism life could not exist; produce O2 and N2 . 6.Microorganisms are decomposers
- 6. 6 6 Impact of microorganisms on Impact of microorganisms on Human Human 1.Microorganisms as Disease agents 2.Microorganisms and agriculture 3.Microorganisms and foods 4.Microorganisms, Energy, and environment 5.Genetic engineering 6.Production of drugs & vaccines
- 8. 8 8 ROBERT HOOKE ROBERT HOOKE One of the most important discoveries of biology occurred in 1665, with the help of a crude microscope, when Robert Hooke stated that life’s smallest structural units were cells.
- 9. 9 9 ANTONY VAN LEEUWENHOEK ANTONY VAN LEEUWENHOEK • First to observe living microbes • His single-lens magnified up to 300X • Between 1674-1723 he wrote series of papers describing his observations of bacteria, algae, protozoa, and fungi
- 10. 10 10 ANTONY VAN LEEUWENHOEK ANTONY VAN LEEUWENHOEK
- 11. 11 11 Question Question • What prevented the science of microbiology from developing before the era(time) of van Leeuwenhoek? • B’se of poor technology
- 13. SPONTANEOUS SPONTANEOUS GENERATION GENERATION Early belief that some forms of life Early belief that some forms of life could arise from could arise from “vital forces” “vital forces” present in nonliving or decomposing present in nonliving or decomposing matter, matter, “ “ abiogenesis” abiogenesis”. . In other In other words, organisms can arise form words, organisms can arise form non-living matter. non-living matter.
- 14. 14 14 LOUIS JABLOT LOUIS JABLOT In 1670 Jablot conducted an experiment in which he divided a hay infusion that had been boiled into two containers: a heated container that was closed to the air and a heated container that was freely open to the air. Only the open vessel developed microorganisms. This further helped to disprove abiogenesis.
- 15. 15 15 REDI’S and JABLOT’S REDI’S and JABLOT’S EXPERIMENTS EXPERIMENTS
- 16. 16 16 THEODOR SCHWANN THEODOR SCHWANN Schwann felt sure that air was the source of microbes and proved this by passing air through strong chemicals and hot glass tubes into heat treated hay infusions in flasks. When the infusions again remained sterile, they suggested that the treatment of the air prevented the growth of microbes.
- 18. 18 18 LOUIS PASTEUR LOUIS PASTEUR • Disproved spontaneous generation of microbes by preventing “dust particles” from reaching the sterile broth • In 1861 completed experiments that lays to rest spontaneous generation. • Showed microbes caused fermentation and spoilage
- 21. 21 21 JOHN TYNDALL JOHN TYNDALL Many scientists were skeptical of Pasteur’s results because some scientists could not reproduce his data and results. Tyndall experiments with boiled infusions resulted in some being sterile and others not sterile. He recognized these mixed results to the present of “heat-resistant forms of life”.
- 22. 22 22 FERDINAND COHN FERDINAND COHN In 1876, a German botanist, Ferdinand Cohn, also discovered “heat-resistant forms of bacteria”. This bacteria are now termed endospores.
- 23. 23 23 GOLDEN AGE OF GOLDEN AGE OF MICROBIOLOGY MICROBIOLOGY The period from 1860 to 1900 is often named the Golden Age of Microbiology. During this period, rapid advances, spear- headed by Louis Pasteur and Robert Koch, led to the establishment of microbiology as a science.
- 24. 24 24 LOUIS PASTEUR LOUIS PASTEUR In 1864 Pasteur established the relationship between microbes and disease in preventing wine from spoiling by using the process termed pasteurization. This process kills bacteria in the alcohol by heat, thus preventing the formation of acetic acid (vinegar).
- 25. 25 25 LOUIS PASTEUR LOUIS PASTEUR His discover of pasteurization, lead Pasteur to introduce the “germ theory of disease” in 1864. Pasteur stated that diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc.
- 26. 26 26 JOHN LISTER JOHN LISTER • In 1867 John Lister, applied the principals of the germ theory to medical procedures. • Lister began soaking surgical dressings and instruments in phenol to kill bacteria. • This resulted in the development of aseptic surgical technique.
- 27. GERM THEORY OF GERM THEORY OF DISEASE DISEASE In 1876 Robert Koch proved the In 1876 Robert Koch proved the “germ theory of disease” “germ theory of disease” by showing by showing that bacteria actually caused that bacteria actually caused disease. disease. KOCH’S POSTULATES KOCH’S POSTULATES
- 28. 28 28 KOCH’S POSTULATES KOCH’S POSTULATES These postulates direct an investigator to: 1. Find evidence of a particular microbe in every case of a disease. 2. Isolate that microbe from an infected subject and cultivate it artificially in the lab. 3. Inoculate a susceptible healthy subject with the lab isolate and observe the resultant disease. 4. Reisolate the microbe from this subject.
- 29. 29 29 Cont Cont • What are the Drawbacks of Koch’s postulates • Some organisms can not be grown in culture • Some microbes exhibit host range that is restricted to human hence can’t produce typical desease in other host • Some microbes keeps mutatation with respect to the change of media/host • Not all diseases are caused by microbes.
- 30. 30 30 ROBERT KOCH ROBERT KOCH • Developed pure culture methods. • Identified cause of anthrax, TB, & cholera.
- 31. 31 31 PAUL EHRLICH PAUL EHRLICH In the 1890’s Ehrlich proposed a theory of immunity in which antibodies were responsible for immunity. In addition, he is known as the father of modern chemotherapy. He speculated about some “magic bullet” that would selectively find and destroy pathogens but not harm the host.
- 32. 32 32 ALEXANDER FLEMING ALEXANDER FLEMING In 1928 Fleming observed that the growth of the bacterium staphyloccus aureus was inhibited in the areas surrounding the colony of a mold that had contaminated a Petri plate. The mold was identified as Penicillium notatum, and its active compound was named penicillin.
- 33. 33 33 WATSON and CRICK, WATSON and CRICK, FRANKLIN, and WILKINS FRANKLIN, and WILKINS In 1953 Watson and Crick determined the structure of DNA. They used their research, together with the research of Franklin and Wilkins to determine the structure of the DNA molecule.
- 34. 34 34 DNA DNA
- 35. 35 35 • 1684: Anton Van: Discovery of bacteria • 1798: Edward Jenner: Small pox vaccination • 1864: Louis Pasteur: Settled the controversy of Spontaneous generation • 1867: Robert Lister • 1884: Christian Gram • 1928: Fredrick Giffith • 1929: Alexandra Fleming • 1946: Joshua Lederberg • 1952: Norton Zinder • 1953: Watson and Group • 1975: Kohler and Cesar Milstein • 1983: Luc Montagnier