Microbiology – Chapter 1



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Microbiology – Chapter 1

  • Microbiology - The science that studies very small living things
  • Usually requires a magnification tool – the microscope
  • Some organisms are large though – Helminths – worms
  • Sub groups of Microbes we will study
  • Bacteria
  • Archaea
  • Fungi
  • Protozoans
  • Algae
  • Viruses
  • Multicellular animal parasites – Helminths

Microbiology – Chapter 1

  • Bacteria

Microbiology – Chapter 1

  • Fungi

Microbiology – Chapter 1

  • Protozoans
  • Giardia Ameba

Microbiology – Chapter 1

  • Viruses
  • Bacteriophage Avian Flu

Microbiology – Chapter 1

  • Helminth
  • Tapeworm Ascaris round worm

Microbiology – Chapter 1

  • Various disciplines of study within microbiology:
  • Bacteriology, Mycology, Parisitology, Immunology,
  • Epidemiology,
  • Biotechnology
  • Virology
  • Environmental Microbiology
  • Bioremediation

Microbiology – Chapter 1

  • Historical review of the Science of Microbiology
  • Robert Hook – 1665 – Englishman, used a primitive compound (two magnifying lenses)
  • microscope, reported that life’s smallest units were little boxes – Cells, his work
  • started the process of the development of the Cell theory of life

Microbiology – Chapter 1

  • Hook’s microscope

Microbiology – Chapter 1

  • Antoni Van Leeuwenhoek –1673 - probably the first person to observe living cells with a simple microscope, amateur scientist, ground his own lenses and described what we know today as bacteria – rod shaped , spiral shaped , etc. “animalcules”

Microbiology – Chapter 1

  • Antoni Van Leeuwenhoek

Microbiology – Chapter 1

  • Francesco Redi – 1668 – opposed the prevailing theory of Spontaneous Generation,
  • maggots in meat , He used covered jars to show that maggots came from flies –strong evidence against spontaneous generation
  • Now we teach the theory of Biogenesis – Life comes from Life
  • But issue of Spontaneous Generation was actively believed for many more years

Microbiology – Chapter 1

  • Francesco Redi

Microbiology – Chapter 1

  • Edward Jenner is credited with first vaccine – in epidemics of smallpox during the late 1700’s he observed that milk maids didn’t get the disease, cattle had a similar
  • disease – cowpox, milk maids had cow pox lesions, but not small pox, he purposefully took scrapings from cowpox blister and scraped a 8 year old volunteer. With the material – child got mild illness but not small pox,
  • Vaccination comes from Latin word “vacca” meaning cow. Jenner laid the foundation for Pasteur’s later work with other vaccinations.
  • (Vaccinia virus similar to Variola smallpox virus, today a possible bioterror weapon – genetically engineered variola?)

Microbiology – Chapter 1

  • Jenner and vaccination

Microbiology – Chapter 1

  • Pasteur – French sceintist that dealt the death blow to the spontaneous generation theory.
  • He devised the ingenious curved necked flasks that prevented contaminated air from reaching boiled beef broth – the broth remained uncontaminated even though exposed to the air
  • He was very lucky – no endopores present, or it would have failed
  • (resitant to boiling)

Microbiology – Chapter 1

  • 1. He developed process we call Pasteuriztion – he heated wine to kill contaminating microbes – cured sick wine (today we heat treatment to kill pathogens in milk also)
  • 2. He proved that fermentation was caused by a microbe – yeast
  • 3. He developed vaccines for rabies and anthrax. Vaccines led to immunity to diseases that routinely killed many people, used to help people long before they understood how they even worked (science of Immunology)
  • 4. He began the revolution in science that led to the Golden Age of
  • Microbiology (from 1857-1914)

Microbiology – Chapter 1

Microbiology – Chapter 1

  • Robert Koch - Developed Koch’s postulates – important technique for determining the
  • actual microbial cause agent of a disease – more later, German, contemporary of Pasteur, several very important contributions
  • 1. He discovered the tuberculosis bug (tubercle bacillus, Mycobacterium tuberculosis)
  • 2. He discovered the cause of anthrax (Bacillus anthracis) – from blood of dead cattle, cultured bacteria in pure culture, injected bacteria in live cattle and they died, then again cultured the bacteria in pure culture. This led to the
  • establishment of a procedure for determining microbial cause of disease (see p. ____-for modern application of Koch’s postulates)

Microbiology – Chapter 1

  • Koch’s postulates

Microbiology – Chapter 1

  • Koch’s and Pasteur’s work helped establish the “Germ Theory of Disease” - that
  • microorganisms cause disease (in people, animals, and even plants)

Microbiology – Chapter 1

  • Iwanowski 1892 - Discovered that plant disease can be caused by small organisms that
  • were so small they passed through filters , Tobacco mosaic virus (TMV) was later
  • identified as the cause - beginning of virology (Today we have discovered new and
  • weird things like viroids, prions) See next slide

Microbiology – Chapter 1

Microbiology – Chapter 1

  • Paul Ehrlich, German doctor, wanted to find a “magic bullet” an agent that would kill
  • the disease agent without hurting the patient (see the “Coming plague” video, part 1)
  • 1. Developed Salvarsan, “salvation from syphilis”agent
  • 2. This was an arsenical – arsenic compound, that was effective against syphilis
  • Antimicrobial agent, medicine to treat a microbial disease, it was chemical – chemotherapy

Microbiology – Chapter 1

  • Syphilis spirochete: T. pallidum Paul Ehrlich

Microbiology – Chapter 1

  • Joseph Lister – 1860’s, English surgeon that applied ideas of the germ theory to surgery, remembered the work of Semmelweis in Hungary in the 1840’s, if a Dr. would wash their hands childbed fever was prevented. He knew that phenol would kill bacteria; put 2 and 2 together and treated wounds with phenol - and no infection (phenol is the basic agent of today’s – Lysol)
  • 1. First antiseptic use in surgery, chemicals used as agents on tissue before surgery
  • (tissue treated with an antimicrobial agent – antiseptic, betadine) disinfectants are chemicals, used on a surface
  • 2. Also proved that microbes cause surgical infections (today’s scourge –MRSA)

Semmelweis

Lister

  • Antisepsis in surgery

Microbiology – Chapter 1

  • Alexander Fleming - Scottish physician and bacteriologist - 1928
  • Observed mold growing on a bacteria culture, there was a ring of clearing around the mold where the bacteria didn’t grow, the mold was later found to be a Penicillium species and the naturally secreted chemical was called penicillin, an antibiotic
  • 1. Antibiotics are natural agents
  • 2. Synthetic drugs are chemicals produced in labs (sulfas)
  • 3. Problems with them - toxicity, resistance, allergic reactions
  • 4. Fleming’s work - shelved until early WWII, sulfas were failing, needed penicillin to cure battle field wounds
  • 5. Now have thousands of antibiotics and synthetics (and a significant problem – resistance)

Flemming and Penicillium

Microbiology – Chapter 1

  • Salk - Polio vaccine, 1950’s polio was a scary epidemic, Salk developed a vaccine by
  • treating the virus with formalin (IPV) inactivated polio virus
  • Sabin 1963 live Polio virus vaccine, attenuated –altered virus, OPV-oral polio vaccine
  • The work done on polio revolutionized the science of virology and we are seeing
  • the results today in advances with Hepatitis and HIV viral infections - tissue
  • culture and other techniques

Avery and Macleod, DNA is genetic material

Watson and Crick, DNA, 1953

DNA Double helix

  • Double Helix

Salk; IPV

Sabin, OPV

Microbiology – Chapter 1

  • Jacob and Monod – 1965 Did research on RNA and protein synthesis in bacteria - last
  • necessary step in understanding how genetics works on a cellular level (Replication,
  • Transcription, Translation – protein synthesis – expression of traits)
  • Modern science thrives today only on the laid foundation of thousands of men and
  • women who did mundane routine and often boring lab science. Don’t forget that we are
  • here today because we stand on the shoulders of Giants – who were people just like you
  • and me. (Who are the Giants today? CDC, USAMRID, young Joe or Mary the graduate
  • student?, maybe you?)

Microbiology – Chapter 1

Microbiology – Chapter 1

  • Classification, Taxonomy, Binomial Nomenclature - Yucchy!!!!! No one likes it. Just do it!!!

The Classification of Living Things

  • Living organisms are assigned to groups based upon their similarities.
  • Systematics is the discipline of identifying and classifying organisms.

Domains

  • The highest – largest category, recent addition
  • 3 domains
    • 1. Archaea – ancient “bacteria”, unicellular like bacteria, also simple cell structure (prokaryote – no nucleus) but have distinct metabolism (chemistry) allowing them to exist in “extreme” environments
    • 2. Bacteria – unicellular, prokaryote, found everywhere (Old kingdom name – Monera)
    • 3. Eukarya – unicellular to multicellular, complex and organized cells with nuclei and organelles (mitochondria)

Domain Archaea

  • Archaea are single- celled organisms that lack a membrane-bound nucleus. - Prokaryote
  • Archaea can be found in environments that are too hostile for other life forms.

Domain Bacteria

  • Bacteria are single- celled organisms that lack a membrane-bound nucleus. (Prokaryote also)
  • Bacteria are found almost everywhere on the planet Earth.

Domain Eukarya

  • The cells of all eukaryotes have a membrane-bound nucleus. Members of the Domain Eukarya are further categorized into one of four Kingdoms. (know these kingdoms)

Microbiology

  • Check your notes; Older 5 kingdom scheme is still widely used
  • Monera – bacteria (Prokaryotic)
  • Protista – Protozoans (Eukaryotic)
  • Fungi - yeast, molds, etc. (Eukaryotic)
  • Plant – photosynthetic producers (Eukaryotic)
  • Animals – heterotrophic consumers (Eukaryotic)

Categories of Classification

  • Domain
    • Kingdom
      • Phylum
        • Class
          • Order
          • Family
          • Genus
          • Species

Categories of Classification

  • Domain - Dumb
    • Kingdom - King
      • Phylum - Philip
        • Class – Came
          • Order - Over
          • Family - For
          • Genus - Good
          • Species - __
          • Spaghetti?

Categories of Classification

    • Domain
    • Kingdom
    • Phylum
    • Class
    • Order
    • Family
    • Genus
    • Species
  • Least inclusive
  • Most inclusive

Categories of Classification

Scientific Names

  • Binomial (two name) Genus first and first letter capitalized, then species not capitalized. If written or typed – either underline or italicize
    • Genus name, species name
    • Homo sapiens - italicized
    • Homo troglodytis (Your EX?) – underlined
    • Canis familiaris – Your puppy (except poodles)
    • Felis domesticus – Your Kitty (some strange people have to have Felis leo or Felis tigris)
    • Canis latrans – Invites your kitty over for lunch
    • Canis lupus - ____________? guess

Know for test

  • 3 domains Archaea, Bacteria, Eukarya
  • 4 Eukarya Kingdoms
    • Protista – Protozoans like Ameba and Paramecium (producers and consumers)
    • Fungi – yeasts, molds, mushrooms (consumers)
    • Plants – complex producers, trees, grasses
    • Animals – complex consumers

Classification of Bacteria

  • Somewhat different: a clinical rapid ID is often important when trying to find causative agent of a disease
  • Bergey’s manual: Manual is in lab for a reference when doing unknown
  • Developed on 1940’s for grouping bacteria according to standard diagnostic lab techniques available at the time (such as Grams stain)

Classification of Bacteria

  • Gram + cocci Gram - bacilli

Classification of Bacteria

  • Gram - Spirochete Gram + bacilli

Classification of Bacteria

  • The manual divides bacteria into 4 groups or divisions on the basis of their Cell Wall
    • 1. Gram + (stain violet)
    • 2. Gram - (destain, and are counterstained pink or reddish color)
    • 3. Bacteria that lack a cell wall (mycoplasma)
    • 4. organisms that have a cell wall lacking “peptidoglycan” (archaeobacteria – Now called “Archaea”

Classification of Bacteria

  • More modern methods now used:
  • 1. DNA studies, genomics, gene probes
  • 2. using Bacterial viruses “bacteriophages”
  • 3. Serology – antibody – antigen reactions (like blood typing)
  • Examples: Salmonella typhi
  • Salmonella typhimurium
  • Azotobacter vinelandii 12837
  • E. coli 0157H7 nasty strain of E. coli


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