Scope and History of Microbiology


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Lecture 1 - The scope and history of microbiology. Based upon chapter 1 from "Microbiology: A Systems Approach" by Cowan.

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Scope and History of Microbiology

  1. 1. The Scope and History of Microbiology<br />Assigned Reading:Chapter 1, pp 1-26<br />
  2. 2. What is Microbiology?<br />micron = small and biologia = studying life<br />How small is “small”?<br />Study of entities too small to be seen with the naked eye (< 0.1 mm)<br />Different perspectives of microbiology:<br /> Collection of disciplines by organism<br /> Confluence of disciplines to study microbes<br /> Microbes have changed history<br /> Microbes have changed science<br /> Microbes have changed the Earth<br />
  3. 3. Diversity of Microbiology<br />
  4. 4. Microorganism Sizes<br />
  5. 5. Sub-Disciplines<br />Fields are historically arranged by the type of microbial system under investigation<br />Bacteriology: Bacteria and Archaea<br />Mycology: Fungi<br />Phycology: Algae<br />Protozoology: Protozoa<br />Virology: Viruses<br />Immunology: The immune response<br />
  6. 6. Microbes Have Changed History<br />Although not always recognized at the time, microbes have dramatically altered human history.<br />Microbes working with us:<br /> Food preservation and preparation for instance<br /> Beer, wine, bread, cheese, sauerkraut, yogurt…<br />Microbes working against us:<br /> Many microbial diseases have altered the outcome of historical events.<br />
  7. 7. History-Altering Microbes<br />Malaria - Plasmodium falciparum (Protozoan)<br />Mosquito-borne infectious disease<br />Thought to have killed Alexander the Great (323 BC)<br />Still an important pathogen<br />Infects ~400,000,000 annually<br />Kills ~2,000,000 annually<br /> that is over 5,000 every day!<br />
  8. 8. History-Altering Microbes<br />Bubonic plague - Yersinia pestis (Bacterium)<br />Vector-borne septicemia<br />Black Death (1347-1351)<br />Between 25-40% of Europe died<br />Loss of laborers contributed to the collapse of the feudal system<br />Lead to the Peasant’s Revolt of 1381<br />Still endemic around the world<br />
  9. 9. History-Altering Microbes<br />Smallpox (Virus)<br />Directly transmissible disease<br />This disease was a big problem in Europe and Asia<br />Variola major has a 40% mortality rate<br />Hernán Cortéz landed in Mexico in 1519<br />Smallpox was brought to the Americas<br />Aztec civilization was decimated<br />Spanish rule over the region was enabled<br />Eliminated by vaccination in 1979<br />
  10. 10. History-Altering Microbes<br />Potato Blight - Phytophthora infestans (Fungus??)<br />Irish potato famine (1845-1849)<br />Potato crops were wiped out<br />~1,000,000 starved to dead<br />~2,000,000 emigrated<br /> Many came to the United States in the mid-1800s<br />Still a chronic problem for potato farmers<br />
  11. 11. Developments in microbiology altered our views of the scope, diversity, and origin of life<br />The germ theory altered our views on the cause, treatment, and prevention of illness<br />The advent of molecular biology and initial advances in genetics were largely driven by microbiologists<br />Microbiology and its offshoots represent the majority of modern biological science<br />Microbes Have Changed Science<br />
  12. 12. Anton Von Leeuwenhoek<br />1684<br />Dutch lens maker<br />First person to see and describe living microbes<br />Simple microscope <br />70 to 250X magnification<br />Made and reportedmany detailedobservations<br />
  13. 13. Aristotle<br />400 BC – Supported<br />Philosopher and early naturalist <br />Made detailed observations of nature<br />Concluded that aphids, fleas, flies, and even mice could spontaneously form from other organic substrates<br />
  14. 14. Francesco Redi<br />1668 - Against<br />Italian natural philosopher<br />Uncovered dishes of meat filled with maggots<br />Covered dishes of meat attracted flies, but maggots formed on the gauze - not the meat<br />Disproved spontaneous generation of maggots<br />
  15. 15. Louis Joblot<br />1710 - Against<br />French mathematician<br />Boiled hay infusions<br />Open container became cloudy<br />Sealed container remained clear<br />Argued that contamination come from outside of the container<br />
  16. 16. John Needham<br />1745 - Supported<br />English scientist<br />Boiled mutton broth<br />Growth observed in both open and closed flasks after boiling<br />Inadequate boiling probably<br />Argued that the growth was intrinsic to the nature of the broth<br />
  17. 17. Lazzaro Spallanzani<br />1768 - Against<br />Italian priest<br />Repeated Needham’s experiment<br />Boiled sealed flasks<br />No growth in flasks until opened<br />Argued that Needham must have contaminated his flask when closing it<br />
  18. 18. Franz Schulze <br />1836 - Against<br />After Priestly discovered oxygen<br />Unheated gasses passed through concentrated acid or base solutions<br />No growth observed inboiled broth media<br />
  19. 19. Theodor Schwann<br />1836 - Against<br />German physiologist<br />Best known for work with nerve tissue<br />Heated incoming gas<br />No growth observed inboiled broth media<br />
  20. 20. Louis Pasteur<br />1864 - Against<br />French microbiologist<br />Used swan-necked flasks<br />Untreated air allowed in and out of flasks<br />No growth in undisturbed flasks<br />Contacting the broth with the dust results in rapid microbial growth<br />
  21. 21. John Tyndall<br />1876 - Against<br />English physicist<br />Built elaborate boxes to eliminate dust<br />Discontinuous heating used to kill endospores<br />Finally laid abiogenesis to rest<br />Oparin and Haldane<br />
  22. 22. Oliver Wendell Holmes<br />American physician – 1834<br />Observed the apparent spread of puerperal fever (Streptococcus) by health care providers<br />Published findings with guidelines to reduce transmission<br />Results largely ignored for twenty years<br />
  23. 23. Ignatz Semmelweiss<br />Vienna physician - 1841<br />Puerperal fever outbreak was severe in his hospital<br />Observed a difference in incidence in clinical wards<br />Forced hand washingwith chlorinatedlime solutions<br />Before germ theory<br />Unpublished and largely ignored<br />
  24. 24. Louis Pasteur<br />French microbiologist - 1862<br />Was contacted by wine producers with a problem<br />The wine was going sour<br />Pasteur thought that the wine was “infected” with detrimental microbes<br />He briefly heated the wine to kill these microbes<br /> Advent of pasteurization<br />Also postulated that if wine can be infected by microbes, people can too<br />This is the beginning of the germ theory of disease.<br />
  25. 25. Joseph Lister<br />British surgeon - 1867<br />Applied germ theory to the treatment and prevention of disease<br />Used carbolic acid (phenol) to clean wounds and operating rooms<br />Disinfection <br />Antisepsis<br />
  26. 26. John Snow<br />British doctor - 1854<br />Cholera outbreak in Soho<br />Tracked incidence in the population<br />Traced source to contaminated drinking water<br />Epidemiology<br />
  27. 27. Robert Koch<br />German microbiologist<br />Contemporary of Pasteur<br />Worked on anthrax, tuberculosis, and cholera<br />Used pure cultures<br />Developed the germ theory of disease<br />Described several postulates for proving the etiological agent of disease (1884)<br />
  28. 28. Koch’s Postulates<br />
  29. 29. Edward Jenner<br />English physician - 1789<br />Studied smallpox outbreaks<br />Variolation had been used<br /> Rather dangerous<br />Cowpox was noted to cause mild lesions in milk maids<br />Used the cowpox virus (vaccinia) to protect against smallpox<br />The first “vaccination”<br />
  30. 30. Advent of Chemotherapy<br />Aniline dyes were observed to inhibit microbial growth<br />Salvarsan - discovered by Ehrlich (1908)<br /> Arsenic compound that inhibited syphilis<br />Penicillin - Fleming (1928)<br /> Commercially available in the 1939<br />Protosil - first sulfa-drug Domagk (1935)<br /> Also the first drug to be used commercially<br />Streptomycin - Waksman and Schatz (1944)<br /> Second antibiotic<br />
  31. 31. Molecular Biology<br />Many of the most critical development of modern molecular biology were worked out in microbes<br />Griffith and Avery study transformation<br />Lederberg developed bacterial genetics<br />Meselson and Stahl studied DNA replication<br />Hershey and Chase study bacteriophage<br />Howard Berg performed first cloning<br />Keri Mullis developed PCR<br />We will revisit these scientists throughout the course.<br />
  32. 32. Taxonomy<br />Kings<br />Play<br />Chess<br />On<br />Fine<br />Green<br />Satin<br />Binomialnomenclature<br />
  33. 33. New Views of Phylogeny<br />Whittaker<br /> versus<br />Woese<br />
  34. 34. Microbes Change the Earth<br />What effect would there be if you removed every human from the earth today?<br />What effect would there be if you removed every mammal from the earth today?<br />What effect would there be in you removed every microbe from the earth today?<br />Microbes cycle all of the biologically important elements on the planet<br />Availability of N, S, P, O, and C are regulated by microbes<br />
  35. 35. Microbial Ecology<br />Beijerinck - Used enrichment cultures to identify environmental isolates<br /> Also discovered the first virus<br />Winogradsky - Used similar techniques to identify nitrogen fixers and chemoautotrophs<br />They began to work out the biochemical roles that microbes play in the environment.<br />Carl Woese - 16S sequencing revealed the archaea<br />Now we begin to appreciate the true diversity of microbes<br />