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MICROBIOLOGY. Introduction & Classification. Topics. Classification Methods of Microbiology Nutrition & Growth Microbial Structure Metabolism Host parasite relationships Control of Growth. Types of Microorganisms. Bacteria Gram positive & gram negative Viruses RNA & DNA Fungi
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MICROBIOLOGY Introduction & Classification
Topics • Classification • Methods of Microbiology • Nutrition & Growth • Microbial Structure • Metabolism • Host parasite relationships • Control of Growth
Types of Microorganisms • Bacteria • Gram positive & gram negative • Viruses • RNA & DNA • Fungi • Yeasts & molds • Protozoa
History • Robert Hooke • Described units in cork as cells Anton van Leeuwenhoek-1667 • Made lenses or simple microscopes
Spontaneous Generation • Abiogenesis-living matter arising from nonliving matter • Redi –maggots & meat • Pasteur et al disproved abiogenesis
Pasteur • Fermentation • Yeast ferment grape juice –alcohol • Bacteria ferment grape juice-acids • Pasteurization
Germ Theory of Disease • Koch • Koch’s postulates • Developed pure culture techniques • Discovered TB agent
Immunology/Chemotherapy • Jenner and smallpox vaccine • Used cowpox virus
Antiseptics • Semmelweis • Lister
Fleming • Discovered penicillin
Taxonomy • System of cataloging organisms • Identification: characterization of organisms • Classification: arrangement of organisms into similar groups • Nomenclature: assign names
Binominal Nomenclature • Genus-capitalized ; collection of species • Microbes – species can be subdivided into strains • Strains have small genetic differences
Rules • Both genus & species underlined or italicized • Strain-subdivision of species • ID by name, number or letter • Example- Escherichia coli- E. coli K12
Classification • Wittaker-5 kingdoms • Plants • Animals • Fungi • Protista • Monera or Prokaryote
Domains • Carl Woese-1980s • Based upon modern techniques • Sequence of rRNA in ribosomes • Three cell types based upon ribosomes
Three Domains • Domains above kingdom level • Bacteria or Eubacteriae • Prokaryotes with peptidoglycan in cell wall • Divide by binary fission • Motile by flagella or cilia • Sensitive to antibiotics
Archaea • Ancient prokaryotes • Cell wall present, not peptidoglycan • Live in extreme environments • Have unusual metabolic processes • Not sensitive to antibiotics
Archaea • Methanogens -strict anaerobes • Produce methane from CO2 + H2 • Live in anaerobic mud lakes • Intestine of cows
Archaea • Halophiles • Require high concentration of salt • Maintain cell wall • Spoilage of food-salted fish • Salt lakes
Archaea • Thermophiles • Live in hot sulfurous waters or acidic water • Nucleic acids/proteins do not function at low temperatures • Volcanic vents in ocean
Eukarya • All eukaryotes • Cell wall varies in composition • Not sensitive to antibiotics • Fungi-yeasts and molds • Protists-slime molds, protozoa, & algae • Plants & animals
Endosymbiotic Theory • Eukaryotes evolved from prokaryotes • Supported by similarities between prokaryotes & organelles in eukaryotes • Mitochondria & chloroplasts same size as prokaryote cell • Contain DNA, 70S ribosomes • Endosymbiont-organism that lives within another
Support for Theory • Prokary Eukary Mitoch & Chloro • DNA circular linear circular • Histones No Yes No • Ribosomes 70S 80S 70S • Growth binary mitosis binary • Cyanophora
Viruses • Obligate intracellular parasites • Not cells so non living agent • No ribosomes • Classification is different
Viroids & Prions • Viroids • Single short piece of RNA • Cause disease in plants • ? In humans • Prions • Protein • Cause neurodegenerate diseases • Humans & animals • CJD & mad cow
New Challenges • Antibiotic resistance • MRSA, VRE & ESBL • Emerging diseases • SARS & Avian Influenza • Bioterrorism • Anthrax, smallpox, plague, botulism