Foundations in Microbiology Sixth Edition Lecture 1: The Main Themes of Microbiology Department of...
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Foundations in MicrobiologySixth EditionLecture 1:The Main Themes of MicrobiologyDepartment of Medical Microbiology, School of Medicine Ilam University of Medical SciencesPresented by Dr. Morovat Taherikalani
*MicrobiologyThe study of organisms too small to be seen without magnificationMicroorganisms include:bacteriavirusesfungiprotozoa helminths (worms) algae
*Branches of Study Within MicrobiologyImmunologyPublic health microbiology and epidemiologyFood, dairy and aquatic microbiologyBiotechnologyGenetic engineering and recombinant DNA technology
*Microbes are Involved inNutrient production and energy flowDecompositionBiotechnologyproduction of foods, drugs and vaccinesGenetic engineeringBioremediationInfectious disease
*Infectious DiseasesNearly 2,000 different microbes cause diseases.10 B new infections/year worldwide13 M deaths from infections/year worldwide
*Characteristics of MicrobesProcaryotes and eukaryotesprocaryote microscopic, unicellular organisms, lack nuclei and membrane-bound organelleseucaryote unicellular (microscopic) and multicellular, nucleus and membrane-bound organellesViruses acellular, parasitic particles composed of a nucleic acid and protein
*Insert figure 1.5 basic cell and virus structures
*Microbial DimensionsProcaryotes are measured in micrometers.Viruses in nanometersHelminths are measured in millimeters.
*Historical Foundations of Microbiology300 years of contributions by manyProminent discoveries include:microscopyscientific methoddevelopment of medical microbiology microbiology techniques
*Antonie van Leeuwenhoek (1632-1723)Dutch linen merchantFirst to observe living microbesSingle-lens magnified up to 300XInsert figure 1.8
*Insert figure 1.9 (a)microscope
Spontaneous GenerationEarly belief that some forms of life could arise from vital forces present in nonliving or decomposing matter (flies from manure, etc)
*Discovery of Spores and SterilizationJohn Tyndall and Ferdinand Cohn each demonstrated the presence of heat resistant forms of some microbes.Cohn determined these forms to be endospores.Sterility requires the elimination of all life forms including endospores and viruses.
*Development of Aseptic TechniquesDr. Oliver Wendell Holmes observed that mothers of home births had fewer infections than those who gave birth in hospitalDr. Ignaz Semmelweis correlated infections with physicians coming directly from autopsy room to maternity ward Nosocomial Infections - infections acquired during stay in hospitals
*Joseph Lister introduced aseptic techniques reducing microbes in medical settings to prevent infectionsinvolved disinfection of hands using chemicals prior to surgeryuse of heat for sterilization
*Pathogens and Germ Theory of DiseaseMany diseases are caused by the growth of microbes in the body and not by sins, bad character, or poverty, etc.Two major contributors: Louis Pasteur and Robert Koch
*Louis Pasteur (1822-1895)Showed microbes caused fermentation and spoilageDisproved spontaneous generation of microorganismsDeveloped pasteurizationDemonstrated what is now known as Germ Theory of Disease Developed a rabies vaccineInsert figure 1.11
*Robert Koch (1843-1910)Established Kochs postulates - a sequence of experimental steps that verified the germ theoryIdentified cause of anthrax, TB, and choleraDeveloped pure culture methodsInsert figure 1.12
*Taxonomy: Organizing, Classifying and Naming Living ThingsFormal system originated by Carl von Linn (1701-1778) Concerned with: classification orderly arrangement of organisms into groupsnomenclature assigning namesidentification discovering and recording traits of organisms for placement into taxonomic schemes
*Levels of ClassificationDomain - Archaea, Bacteria & EukaryaKingdomPhylum or DivisionClass OrderFamilyGenusspecies
*Naming MicoorganismsBinomial (scientific) nomenclature Gives each microbe 2 names:Genus - noun, always capitalizedspecies - adjective, lowercaseBoth italicized or underlinedStaphylococcus aureus (S. aureus)Bacillus subtilis(B. subtilis)Escherichia coli(E. coli)
*3 DomainsBacteria - true bacteria, peptidoglycanArchaea - odd bacteria that live in extreme environments, high salt, heat, etc.Eukarya- have a nucleus and organelles
*Insert figure 1.15Woese-Fox System