270 likes | 355 Views
Chapter 1. The Microbial World and You. What are microorganisms?. Too small to be seen with the unaided eye True cellular forms Ubiquitous Both helpful and problematic. Scope and Relevance of Microbiology. First living organisms on the planet Live everywhere life is possible
E N D
Chapter 1 The Microbial World and You
What are microorganisms? • Too small to be seen with the unaided eye • True cellular forms • Ubiquitous • Both helpful and problematic
Scope and Relevance of Microbiology • First living organisms on the planet • Live everywhere life is possible • Largest component of Earth's biomass • Ecosystems depends on their activities
Why study microbes? • Recycling vital elements • Bioremediation • Agriculture • Biotechnology/ Genetic engineering • Food microbiology • Industrial Microbiology • Normal microbiota • Disease causing microorganisms
Common Ancestor • Gave rise to 3 Domains • Two prokaryotic • Bacteria and Archaea • One eukaryotic • Eukarya
Prokaryotes • Asexual; unicellular, no membrane bound organelles • Archaea • Not known to be human pathogens • Usually found in extreme environments • Bacteria • Some pathogenic • Multiple morphological and physiological differences from archaea
Rod Shaped Bacteria Round Archaea Many Klebisella pneumoniae cells Methanococcus janaschii, with numerous flagella attached to one side
Eukaryotes • Unicellular or multicellular • Sexual and asexual reproduction • Multiple membranous organelles • Algae • Unicellular or multicellular • Photosynthetic • High morphological diversity • Not pathogenic
Cymatopleura Volvox Macrocystis pyrifera Gelidium pulchrum Alexandrium tamarense
Fungi • Unicellular or multicellular • Absorb nutrients from their environment • Primarily opportunistic pathogens Saccharomyces cerevisiae Rhizopus Aspergillus flavus Amanita muscaria
Protozoa • Unicellular • Most are mobile • Pseudopods, Flagella, Cilia • Absorb nutrients from environment or live as parasites • Manyare pathogenic
Amoeba Giardia lamblia Paramecium
Helminths • Multi-cellular animals • Flatworms and round worms • Many are pathogenic • Only some life stages microscopic Taenia taeniformis Necator americanus
Viruses • Obligatory intracellular parasite • No true cellular organization • Living or non-living??? HIV virus on the surface of a CD4+ cell Bacteriophages
History of Microbiology • Robert Hooke -1665 • Anton van Leeuwenhoek - 1673 • "animalcules" • Schleiden and Schwann- 1838/39 • Cell theory
Spontaneous Generation • Franscesco Redi – 1668 • John Needham – 1745 • Lazzaro Spallanzani - 1765
Rudolf Virchow -1855 • Louis Pasteur – 1861 • Aseptic techniques
Support theories that invisible agents cause disease • IgnazSemmelweis - 1840 • Childbed fever • Joseph Lister - 1867 • Aseptic surgery • John Tyndall • Microbes in dust, some heat resistant
Germ Theory of Disease • Pasteur • Fermentation (1857) and pasteurization (1864) • Robert Koch - 1876 • Walther Hesse – 1882
Vaccination • Edward Jenner – 1798 • Smallpox vaccine • Louis Pasteur – 1880 • Avirulence • Rabies vaccine
1908, Paul Ehrlich Salvarsan – treatment for syphilis 1928, Alexander Fleming Discovered properties of penicillin 1935-36, Gerhard Domagk & Ernest Fourneau Development of sulfa drugs Chemotherapy
1940, Selman Waksman • Isolated antibiotic from Streptomyces • 1940, Howard Florey & Ernest Chain • Preformed clinical trials and mass produced penicillin
Problems with modern chemotherapeutics • Toxicity • Resistance • Lack of adequate anti- viral drugs
Infectious disease remains a threat • 750 million cases each year in US • Emerging diseases • Factors associated with emerging disease • Microbial evolution • Changing human behavior/lifestyles • Complacency of human population • Population expansion/global travel