Fundamentals Microbiology Notes Introduction Objectives: () Define: microbiology microbe biogenesis () Briefly describe the roles of microorganisms. () Briefly describe the contributions of the following individuals: Leeuwenhoek Holmes Hooke Ehrlich Schleiden and Schwann Jenner Redi Fleming Needham Florey and Chain Spallanzani Linnaeus Pasteur Roux Virchow Metchnikoff Koch Beijerink Semmelweis Domagk Lister () Define: cell theory vaccination germ theory of disease chemotherapy fermentation () Explain the significance of Koch’s Postulates. (see book) () Be able to write the scientific names of microorganisms. () Describe Woese’s 3 domain system of classification. Describe the types of microorganisms you would find in each domain. 1) 2) Microbiology: the study of microscopic organisms (also called microbes) I. Roles of microbes A. Beneficial a. basis of food chains on earth (photosynthetic or chemosynthetic microbes feed the low level consumers) b. role in nutrient cycles on earth such as the nitrogen cycle c. decomposer organisms – break down dead materials for recycling d. production of foods: bread, cheeses, yogurt, sauerkraut, wine, beer e. production of industrial products: organic acids, vinegar f. production of antibiotics g. production of genetically engineered products: human insulin, human growth hormone, interferon B. Detrimental a. decomposer organisms – decomposition of things you may not want to break down (when you build a fence outside, you need to use lumber which has been pressure-­‐treated so the fungi and bacteria won’t cause the wood to rot. b. Pathogens – organisms that are capable of causing disease Designation and Classification of Microorganisms I. Scientific notation – binomial nomenclature – the 2 named naming system devised by Carolus Linnaeus to specifically designate different types of organisms A. Each organism has a genus and a species name – in Latin, italicized or underlined. e.g. Staphylococcus aureus B. The genus name is a noun and is capitalized e.g. Staphylo (grapes) coccus (round) , Staphylococcus aureus is an organism which is typically seen as clusters of round cells under the microscope, resembling grapes. C. The species name is an adjective and is in lower case e.g. aureus (golden) Staphylococcus aureus has a golden yellow color when grown in the lab.) II. Classification A. There have been many classification schemes or living things B. Initially, it was thought there were 2 kingdoms, plant and animal C. When microbes were discovered, it was apparent additional kingdoms were needed. Ultimately a kingdom was designated for bacteria and their relatives (Prokaryota or Monera) and for protozoa (Protista) D. Refinements in molecular biology have led to the discovery that there are actually three distinct types of cells found among all things we know of as living – two which lack a defined nucleus (Bacteria and Archae) and one type of cell with a nucleus (Eukarya) These were grouped into 3 domains by Carl Woese in 1978 E. The Bacteria domain contains typical; bacteria, cyanobacteria (also called bluegreen algae), and bacterial relatives such as chlamydias F. G. 3) III. Note that viruses have no place in this classification scheme because they are not truly defined as living things. History of Microbiology I. II. The Archaea domain contains organisms that live in extreme environments such as areas of high salt concentration or extreme heat or acidity The Eukarya domain has microscopic representatives in a variety of kingdoms or groups; protozoa, algae, fungi such as yeasts or molds, parasitic helminthes (worms) III. IV. Leeuwenhoek – father of the microscope A. Dutch merchant – ground lenses of good quality B. First observed microorganisms in pond water and called then weeanimalcules – reported them to the Royal Society Cell Theory -­‐ All living things are composed of cellular units and all cells come from previously existing cells. A. Hooke – observed slices of cork and saw a regular arrangement of structure. These were actually the dead walls – he called them cells B. Scheiden and Schwann – observed many different plant and animal tissues, and always found cellular structure – they put forth the first part of what is now called the Cell Theory. All living things are composed of cellular units. C. Origin of cells – 2 Theories a. Spontaneous generation – life from non-­‐living material a. Biogenesis – life from life D. Redi – disputed spontaneous generation with his experiment proving maggots could not be spontaneously generated from a piece of meat E. Pasteur – father of microbiology, disputed the spontaneous generation of microbes with the swan-­‐neck flask experiment F. Virchow – Took work of all these and stated the second part of the cell theory – biogenesis, that all cells come from previously existing cells Fermentation A. French wine industry brought problem of sick or sour wine to Pasteur B. Pasteur found two groups of microorganisms in the sour wine a. yeast cells which converted sugar to alcohol b. bacteria which convert sugar to acid C. Devised heating procedure called Pasteurization to destroy unwanted organisms Germ Theory of Disease A. French silk industry brought the problem of pebrine disease to Pasteur which was destroying silkworms B. Pasteur investigated worms and moths and found a protozoan parasite in diseased stock. C. D. E. F. G. H. I. J. Recommended quarantine and destruction of diseased stock One of the first recorded incidents in which a microorganism was found to cause a disease This was a unique concept to individuals who believed disease was a result of sin. Koch – Father of bacteriology a. Established aseptic techniques still used in microbiology laboratory b. Grew cultures on solid culture media allowing for isolation into pure cultures c. Taught the first true microbiology course d. In work with anthrax developed a protocol to establish the relationship between a particular microbe and a specific disease state. This protocol actually proved the Germ Theory of Disease Lister – practical application of the Germ Theory to a clinical situation a. Lister was a surgeon who was appalled at the high rate of post operative infections especially amputations b. Found that carbolic acid (phenol) could kill microorganisms c. Soaked instruments, bandages, swabbed surgical area with carbolic acid. Also he had all staff wash their hands in it and sprayed an aerosol in the operating area d. Dramatically reduced infection rate Semmelweis and Holmes – clinical application to the problem of puerperal fever (childbirth fever) a. Semmelweis (Europe) and Holmes (US) noted the high infection rate when births were attended by medical students fresh from the autopsy room b. Used chlorinated lime (bleach) to disinfect c. This practice reduced infections drastically Jenner – Father of vaccination cowpox and smallpox a. Jenner noted that individuals who had contracted a disease called cowpox seemed immune to the periodic outbreaks of smallpox that could decimate a community b. He conducted an experiment to first inoculate a young boy with cowpox, and then challenged him with smallpox; fortunately for the young boy, it was successful leading to widespread immunizations Pasteur – in his attempt to prove the Germ Theory of Disease created a vaccine against chicken cholera a. Through a laboratory mistake he recognized that it was possible to use cultures that were attenuated or weakened as protection against virulent strains b. He later developed other vaccines such as the rabies vaccine c. These vaccines work through active immunity – your own body produces the defense K. L.. M. N. O. P. Q. Roux – passive immunity – another organism produces antibodies that you can then utilize a. Symptoms of diphtheria are caused by a toxin produced by a microorganism b. Roux developed an antitoxin to be used in treatment by injecting small amounts of toxin into a large animal such as a horse or cow c. Over time the animal’s blood can be separated to yield antibody rich serum Metchnikof – colleague of Pasteur a. Observed leukocytes ingesting bacteria through phagocytosis b. Recognized the potential of this action as a defensive mechanism in the body Beijerinck – Virology a. Discovered nonfilterable agents of disease (too small to be trapped by a filter) b. He called them viruses and postulated about their life style c. At first there was little except Quinine for malaria – bark of chinchona tree Ehrlich – Father of chemotherapy a. Postulated about the use of drugs which would act as a “magic bullet” (selectively toxic) to destroy infectious agents without harming host tissue b. Developed Salvarsan (an arsenic compound) against syphilis (effectiveness now under controversy) Domagk – development of sulfonamide (sulfa) drugs a. Synthetic drugs from coal tar dyes b. Where drugs of choice against bacterial infections until resistant strains appeared Fleming – discovery of penicillin a. found penicillium mold growing on plates of Staphylococcus aureus, inhibiting growth b. Recognized potential of bacteriostatic compound produced by one organism against another – antibiotic c. Also discovered lysozyme, an enzyme in body secretions which can break down bacterial walls Florey and Chain – developed penicillin into a practical agent a. Grew mold in mass cultures b. Isolated penicillin in stable form c. Performed animal testing Source: Created for Dr. Yurko’s Microbiology class, edited by LLC staff, January 2012 for FSCJ South campus Library Learning Commons Science Lab. Permission to copy and use is granted for educational use provided this copyright label is displayed.