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Chapter 1 Outline:. Introduction and History of Microbiology. Define:. Microbiology – the study of little life forms Microbe, microorganism, agent -- microbe = microorganisms and nonliving agents -- microorganism = small organism -- agent – nonliving entity studied in microbiology
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Chapter 1 Outline: Introduction and History of Microbiology
Define: Microbiology – the study of little life forms Microbe, microorganism, agent -- microbe = microorganisms and nonliving agents -- microorganism = small organism -- agent – nonliving entity studied in microbiology Germ, pathogen -- disease-causing microbe
List several ways in which microbes affect us: • Photosynthesis • Nitrogen fixing • Break down wastes/organic matter • Part of normal flora on/in our bodies • Used to produce food: yogurt, bread, wine, etc. • Make vaccines, insulin, enzymes • Bioremediation: cleaning up pollution, ex. Oil spills • Pathogens
Nitrogen fixing N2 amino acids (used to build proteins)
Making products Bacterial chromosome • Example: + Human insulin gene E. coli Human insulin gene inserted into chromosome Human insulin
Bioremediation Alaska-in-pictures.com http://www.alaska-in-pictures.com/bioremediation-project-3253-pictures.htm
Naming and classifying microbes Naming Organisms Scientific names 2 parts genus + specific epithet = species name underlined or in italics genus capitalized; specific epithet not Non-living (like viruses and prions) Usually named for disease, condition
Classifying Organisms 3 Domains: Eubacteria (true bacteria, includes pathogens) Archaea (archaebacteria, live in extreme env.) Eukarya (plants, animals, fungi, protistans) Prokaryotes vs. eukaryotes Non-living (viruses) Based on characteristics, such as DNA vs. RNA
Virus classification • Type of nucleic acid • Ds (double-stranded) or ss (single-stranded) • Enveloped vs. non-enveloped • Shape
Types of microbes studied in microbiology: 1. bacteria: prokaryotic unicellular peptidoglycan cell wall divide by binary fission
2. viruses: acellular nucleic acid + protein coat (capsid) parasitic in host cells
3. fungi: eukaryotic secrete digestive enzymes and absorb nutrients molds, yeasts, etc.
4. protists (sometimes called protozoans): eukaryotic unicellular classified by means of movement, ex. Amoeba
Giardia movie clip • 1_13_giardia.mov.zip
5. helminths: multicellular worms – usually diagnosed by microscopy ex. Tapeworms, pinworms
6. prions: infectious proteins newly discovered Ex. Mad Cow disease, Creutzfeldt-Jakob disease, scrapie, kuru
7. the immune system: body’s response to pathogen action of pathogen humoral vs. cellular immunity (antibodies) (T cells—virally infected cells, cancer)
Branches of microbiology: • Bacteriology • Virology • Mycology • Parasitology • Molecular biology • Immunology
History of microbiology Ancient times Production/preservation of foods Embalming 1600s to 1800 Robert Hooke and his “cells” of cork Antony van Leeuwenhoek sees first living “animalcules” Francesco Redi and his jars of meat (starts to disprove spontaneous generation) Edward Jenner and the first vaccine (against smallpox)
courtesy of CDC/ Jean Roy Public Health Image Library
History of microbiology 1800s Louis Pasteur disproves spontaneous generation with swan neck flasks His other work: Fermentation processes caused by microbes Wine industry and pasteurization (control of microbes) Silkworm disease caused by protozoan Rabies vaccine and Joseph Meister Isolation of viruses by filtration through porcelain
Bacillus anthracis Courtesy of CDC/ Dr. William A. Clark Public Health Image Library
A case of cutaneous anthrax Courtesy of CDC Public Health Image Library
History of microbiology The Germ Theory Robert Koch (“coke”) and Bacillus anthracis diseases had been associated with bad/immoral behavior, punishment from God, evil spells, swamp vapors, etc. … not microbes…until Koch Koch’s Postulates: 1. Disease and microbe must always be present together in host. 2. Isolate microbe in pure culture. 3. Infect new, healthy host with microbe from pure culture and produce disease again. 4. Reisolate microbe from 2nd host in pure culture. (Development of agar and establishment of pure cultures were crucial to Koch’s Postulates.)
Robert Koch 1843-1910
History of microbiology Joseph Lister: surgeon who first sterilized surgical instruments and wounds Ignaz Semmelweis: hand hygiene prevents childbed fever
Semmelweis’ Hand Hygiene Intervention Hand Hygiene: Not a New Concept ~ Hand antisepsis reduces the frequency of patient infections ~ Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999.