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					Microbiology
   Chapter 1
         Part I
Introduction to Microbiology
Scope of Microbiology
   Microbes
       Life forms which require magnification for
        viewing
       Ubiquitous
       Each group has a distinct set of biological
        characteristics
            Single celled vs. multi-celled
            Prokaryotic vs. eukaryotic
            Cell wall vs. no cell wall
            Autotrophic vs. heterotrophic
            Cellular vs. acellular
Prokaryotic vs. Eukaryotic
Assigning Characteristics
   Bacteria

   Protozoa

   Fungi

   Algae

   Helminths

   Viruses

               Assign common characteristics to each group
                                                                           Mycobacterium tuberculosis. Acid
                                                                           fast bacteria (shown in pink) like
                                                                           this causes TB and leprosy. Light
(Top) Coccidioidomycosis Arthrospores      Schistosoma (worms) at          blue is Staph epi, a common
(Bottom) Development of Arthrospores       two different stages of         bacteria cocci which inhabits the
Into spherule in lung tissue               development – liver             Skin. Not a common pathogen
Fungal Infection of the lung               Disease and other symptoms

Staphylococcus Aureus       Trypanosoma                 Treponema pallidum                 Herpes Virus
Gram positive bacteria      Eukaryotic pathogen         Bacterial spirochete
Staph infections and MRSA   African Sleeping Sickness   Causes syphilis
Size
Comparisons
                                      What Do
                                    Microbes Do?




Photosynthesis       Microbial                      Bioremediation
                                       Genetics,
Decomposition      Physiology &                        Oil Eating     Infectious
                                         Gene
 Soil Fertility   Fermentation of                     Bacteria &       Disease
                                      Regulation
       &              Cheese                              Fungi           &
                                          &
  Microbial            Wine                             Water        Immunology
                                    Biotechnology
   Ecology             Bread                          Purification




                                                     Ch 27 Briefly
                                                       Need an
                                                                     Ch 14 – 16
                                                    Environmental
Ch 4, 7, & 26       Ch 8 & 27         Ch 9 & 10                          &
                                                      & Applied
                                                                     Ch 18 - 25
                                                         Micro
                                                        Course
     Part II
Historical Figures in
    Microbiology
Superstition of Microbiology
   Spontaneous generation
       For thousands of years people believed that
        living things arose from vital forces present in
        non living matter
       Mushrooms appearing on rotting wood
       Afflicted people were thought to be cursed
   Controversy between…
       Abiogenesis and biogenesis
First Look at Microbes
    In the 1600s
        Robert Hooke (English)
         reported that living things
         were composed of little
         boxes or cells
        Antonie van Leeuwenhoek
         construction microscopes
         which could magnify 300X
             Described microorganisms that
              he observed in teeth scrapings
              & rain water
Abiogenesis vs. Biogenesis
   Franceso Redi
       He wanted to ascertain whether maggots arose
        from some “vital force” of the meat or were
        offspring of flies
Abiogenesis vs. Biogenesis
   Conclusions of Redi’s Experiment
       This and related experiments proved that
        complex animals such as insects and mice
        develop through biogenesis
       However, meat leaf out but covered with
        gauze would still rot
       Therefore, the idea that simpler organism
        could arise from abiogenesis was still accepted
Proving that Microbes Are Present in
Dust Particles
   Jablot’s vs. Needham’s Experiment
       Jablots experiment supported the idea that
        microbes are present in the air
Proving that Microbes Are Present in
Dust Particles
 However, support for Jablot’s experiment
  faltered when Needham’s results were
  reported
 Needham performed the same experiment
  with mutton gravy
 Microbial growth was in both containers
 What do you think happened here?
Proving that Microbes Are Present in
Dust Particles
   These disputes would
    be put to rest with
    Louis Pasteur’s work
Pasteurization
   Pasteur also demonstrated that
    spoilage bacteria could be killed
    by heat that was not hot
    enough to evaporate the
    alcohol in wine. This application
    of a high heat for a short time
    is called pasteurization
Lister’s Work
 English physician advanced the idea of
  antisepsis in health care setting 1860’s
 Dressed wounds with carbolic acid
  (phenol)
 Reduced deaths among patients by 2/3
 Listerine Mouthwash
Koch’s Postulates
 1876 Robert Koch provided proof that a
  bacterium causes anthrax and provided
  the experimental steps, postulates, used
  to prove that a specific microbe causes a
  specific disease
 Koch was a physician and Pasteur’s young
  rival
Koch’s Postulates
                            Take scraping and plate on agar

Mouse dies with sores

                        A heterogeneous population of bacteria
                        Grow – which one is the causative agent



                        Isolate all different strains and types and
                        inject into healthy mice and see which mice
                        develop similar phenotype and symptoms



                        Take a sample again from mice which died
                        of same symptoms and isolate the
                        causative agent again
Koch’s Postulates

A sequence of
experimental
steps to relate a
specific microbe
to a specific
disease
Koch’s Postulates


Used to prove the
specific causative
agent of an infectious
disease
Jenner’s Work
 Observed that milkmaids did not acquire
  smallpox
 Milkmaids were exposed to chronic low
  doses of cowpox and therefore acquired
  specific immunity
 1796 Jenner inoculated a person with
  cowpox virus and found this person was
  then protected against acquiring small pox
 This protection is known as immunity
 Called vaccinatin from vacca for cow
Alexander Fleming’s Work
   In 1928 Fleming
    discovered the first
    antibiotic by accident
   He observed that
    Penicillium fungus
    secreted a substance
    which killed bacteria
   Explain why a fungus
    would do this
   In 1940s penicillin was
    tested clinically and
    mass produced
Germ Theory of Disease
 All of these aforementioned people and
  others helped give rise to the germ theory
  of disease
 Germ Theory states that microorganisms
  can invade other organisms and cause
  disease
 Before this many time politics and religion
  would spur on erroneous theories
      Part III
Introduction to Disease
Chronic vs. Infectious Disease
   Chronic
       Disease which persists over a long period of
        time
       Atherosclerosis, cancer & heart failure
   Infectious
       Organism enters and tissues & grows
            Bacterial – Prokaryotic
            Viral – Acellular
            Protozoan – Eukaryotic
       Causes symptoms in patients
Conquering Infectious Disease
   The triumph over infectious disease?
       Antibiotics discovered in 1940s
       Vaccinations routinely delivered in the 1950s
        through today
       Eradication of polio and small pox
   But then…
       MRSA
       Drug resistant TB
       HIV
       Ebola
       Avia Flu
       And more
Conquering Infectious Disease
   What went wrong?
       Medical advances
            Older and sicker people live longer
            More susceptible to garden variety microbes
       Population is more mobile
       Emerging diseases
            Encroachment of humans into wild habitat
       Rapid evolution and biochemical changes to
        microbes
            Microbes have a quick generation time
                       All Diseases




Old Standards           Emerging                Reemerging
                           Avia Flu             Tuberculosis - TB
     Syphilis
                     Antigenic shift event         New drug
     Measles
                       HIV in the 80’s          resistant strains
 Staph Infections
                    West Nile in US in 2001   Immunocompromised
   Chicken Pox
                      Continental travel            patients
Top Causes of Death
United States            Deaths     Worldwide               Deaths
1. Heart Disease         696,950 1. Heart Disease           8.12 x 106
2. Cancer                557,270 2. Stroke                  5.51 x 106
3. Stroke                162,670 3. Res infection           3.88 x 106
4. Chronic LRD*          124,800 4. Cancer                  3.33 x 106
5. Accidents             106,740 5. HIV/AIDS                2.78 x 106
6. Diabetes              73,250     6. Chronic LRD*         2.75 x 106
7. Flu & Pneumonia       65,680     7. Diarrheal disease 1.80 x 106
8. Alzheimer disease 58,870         8. Tuberculosis         1.57 x 106
9. Kidney problems       40,970     9. Malaria              1.27 x 106
10.Septicemia            33,865     10. Accidents           1.19 x 106
                   * Stands for lower respiratory disease
                   Infectious Diseases are shown in red
Infectious
Disease
Statistics
     Part IV
Taxonomy & Biological
    Classification
Organizing Life
   Classification
       Orderly arrangement of organisms into groups
        that indicate evolutionary relationships
   Nomenclature
       Assigning names to various taxonomic
        rankings
   Identification
       Correct placement of organism into taxonomic
        scheme
Taxonomy
   Origins of organizing biological life
       Carl von Linne or Linnaeus 1701 – 1778
       System of recognizing and defining properties
        of living organism followed by the placement
        into specific slots
       Grouped according to similar properties
       Grouped according to evolutionary relatedness
       Constantly being revised and refined
Taxonomy
Nomenclature
 Scientists use a standard binomial system
 Overseen by an international group
       Verify that standard procedures were followed
       Ascertain the uniqueness of each name
       Make sure no other name exists
Nomenclature
   Staphylococcus aureus
       Staphule – bunch of grapes
       Aureus – golden
   Campylobacter jejuni
       Kampylos – curved
       Bakterion – little rod
       Jejunum – section of small intestine
   Giardia lamblia
       Alfred Giard – French microbiologist
       Vilem Lambl – Bohemian physician
Evolution & Phylogeny
   Evolution
       All new species originate from preexisting
        species
       Closely related organism have similar feature
        due to evolution from common ancestral forms
   Phylogeny
       Tree of life
       Classification based on evolutionary
        relatedness
Whittaker’s
System
Whittaker’s System
 Although used for many years this system
  has problems in terms of evolutionary
  relatedness
 Kingdom Protista
       Autotrophs & heterotrops are groups together
   Archaea
       Although these organisms are prokaryotic they
        are more closely related to eukaryotic cells
Solution to Whittaker’s Tree
 Biologist no longer group organisms into a
  5 kingdom system
 Currently a three domain system
       Many original kingdoms still work
            Plants, animals, fungi
       However, Kingdom Protista & Kingdom Monera
        have been extensively reorganized into many
        different kingdoms
Three Domain System

				
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posted:12/3/2011
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