chapter 1 outline:
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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 - PowerPoint PPT PresentationTRANSCRIPT
Chapter 1 Outline:
Introduction and History of Microbiology
Define:Microbiology
– the study of little life formsMicrobe, microorganism, agent
-- microbe = microorganisms and nonliving agents
-- microorganism = small organism-- agent – nonliving entity studied in
microbiologyGerm, 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
Photosynthetic cyanobacteria
Nitrogen fixingN2 amino acids (used to build proteins)
Break down wastes/organic matter
Normal flora (microbiota)
Foods produced by microbes
Making products Example:
+
E. coli
Bacterial chromosome
Human insulin gene
Human insulin
Human insulin gene inserted into chromosome
Bioremediation
Alaska-in-pictures.comhttp://www.alaska-in-pictures.com/bioremediation-project-3253-
pictures.htm
Naming and classifying microbesNaming
OrganismsScientific names2 partsgenus + specific epithet = species
nameunderlined or in italicsgenus capitalized; specific epithet
notNon-living (like viruses and prions)
Usually named for disease, condition
ClassifyingOrganisms3 Domains:Eubacteria (true bacteria, includes pathogens)Archaea (archaebacteria, live in extreme env.)Eukarya (plants, animals, fungi, protistans)Prokaryotes vs. eukaryotesNon-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:
prokaryoticunicellularpeptidoglycan cell walldivide by binary fission
Figure 1.1a
2. viruses: acellularnucleic acid + protein coat (capsid)parasitic in host cells
3. fungi: eukaryoticsecrete digestive enzymes and absorb nutrientsmolds, yeasts, etc.
Figure 1.1b
4. protists (sometimes called protozoans): eukaryoticunicellularclassified by means of movement, ex. Amoeba
Figure 1.1d
Giardia movie clip 1_13_giardia.mov.zip
5. helminths: multicellular worms – usually diagnosed by
microscopy ex. Tapeworms, pinworms
6. prions: infectious proteinsnewly discovered
Ex. Mad Cow disease, Creutzfeldt-Jakob disease, scrapie, kuru
Normal protein and prion
7. the immune system:body’s response to pathogenaction of pathogenhumoral vs. cellular immunity(antibodies) (T cells—virally infected cells,
cancer)
Figure 1.1e
Antibodies attaching to bacterium
T cells
Branches of microbiology: Bacteriology Virology Mycology Parasitology Molecular biology Immunology
History of microbiologyAncient times
Production/preservation of foodsEmbalming
1600s to 1800Robert Hooke and his “cells” of corkAntony 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)
Figure 1.2 - Overview
courtesy of CDC/ Jean RoyPublic Health Image Library
History of microbiology1800s
Louis Pasteur disproves spontaneous generation with swan neck flasksHis other work:Fermentation processes caused by microbesWine industry and pasteurization (control of microbes)Silkworm disease caused by protozoanRabies vaccine and Joseph MeisterIsolation of viruses by filtration through porcelain
Figure 1.3 - Overview
Courtesy of CDC/ Dr. William A. ClarkPublic Health Image Library
Bacillus anthracis
A case of cutaneous anthrax
Courtesy of CDCPublic Health Image Library
History of microbiologyThe Germ Theory
Robert Koch (“coke”) and Bacillus anthracisdiseases 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 Koch1843-1910
History of microbiology
Joseph Lister: surgeon who first sterilized surgical instruments and wounds
Ignaz Semmelweis: hand hygiene prevents childbed fever
Hand Hygiene: Not a New Concept
Maternal Mortality due to Postpartum Infection General Hospital, Vienna, Austria, 1841-1850
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1841 1842 1843 1844 1845 1946 1847 1848 1849 1850
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MDs Midwives
Semmelweis’ Hand Hygiene Intervention
~ Hand antisepsis reduces the frequency of patient infections ~
Adapted from: Hosp Epidemiol Infect Control, 2nd Edition, 1999.
History of microbiology1900s:
Paul Ehrlich and salvarsan: first chemical treatment for disease (syphilis)Sulfa drugsAlexander Fleming and penicillin1940s and WWII – mass production of penicillin1950s – Age of Antibiotics begins1953 – structure of DNA1970s – restriction enzymes (molecular “scissors”) discovered1980s – PCR = polymerase chain reaction; copying DNA1997 – prions2000 – the Human Genome Project2001 – 9/11/2001 and bioterrorism2003 – new disease called SARS; first case of the “bird”flu2005 – growing awareness of the avian flu; world governments mobilize/prepare2009 – H1N1 influenza (swine flu)
Alexander Fleming
Figure 1.5
Kary B. MullisThe Nobel Prize in Chemistry 1993
the polymerase chain reaction (PCR) method
Dr Bruce Ivins, a a biodefense researcher at Fort Detrick. Photograph: Frederick News Post/AP
“Detrick anthrax scientist commits suicide as FBI closes in”August 01, 2008
The End