Microbiology -INTRODUCTION

• Cocci bacteria are spherical or oval in shape and may occur singly, in pairs, chains, tetrads, or clusters.
• Microbes - Acellular Infectious Agents and Cellular

  Microorganisms+

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  Acellular Infectious Agents -Prions and Viruses+

  Cellular Microorganisms - Procaryotes and eukaryotes+

  Procaryotes - Archaea and Bacteria +

  Eucaryotes- Algae, Fungi, Protozoa
• Spirilla is spiral shaped
• Bacillus is rod shaped with rounded ends
• Bacillus is rod shaped
• Vibrio is comma shaped
• Mycoplasmas are the smallest free living organism known to man
• Archaea have no cell wall
• The three domains of life include Archaea, Bacteria, and Eukaryota
• Eukaryotes have membrane bound nuclei, mitochondria, chloroplasts, and other membranous structures
• Prokaryotes do not have membrane bound nuclei or any other membranous structure
• • Microbes that live on and in our bodies are referred to as our indigenous microflora
• Infectious Disease: A disease caused by a pathogen that is spread from one person to another.
• Microbial Intoxication: Intoxication caused by the consumption of food or drink that contains harmful microorganisms.
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  • they are essential for life on this planet
  • Photosynthetic algae and bacteria (such as cyanobacteria) produce much of the oxygen in our atmosphere
• • Many microbes play essential roles in various elemental cycles; e.g., the carbon, nitrogen, oxygen, sulfur, and phosphorous cycles
• Microbes and Nitrogen Fixation: Nitrogen Fixation is the process by which nitrogen is converted into ammonia
• • Microbes are used in many industries; e.g., food, beverage, chemical, and antibiotic industries and in genetic engineering
  • In genetic engineering, a gene or genes from one organism is/are inserted into a bacterial or yeast cell; the cell that receives the new gene(s) is then capable of producing the gene products) coded for by the newgene(s)
  • The use of living organisms or their derivatives to make or modify useful products or processes is call biotechnology
• • Fossils of primitive microorganisms date back about 3.5 billion years ago.
  • Candidates for the first microorganisms on Earth are archaea and cyanobacteria.
  • Infectious diseases of humans and animals have existed for as long as humans and animals have inhabited the planet.
  • Earliest known account of pestilence occurred in Egypt in about 3180 BC.
• Louis Pasteur (1822-1895)

  • French chemist who made numerous contributions to microbiology

  -Investigated different fermentation products

  -Developed the pasteurization process

  -Discovered life forms that could exist without oxygen (anaerobes)

  -Developed several vaccines, including rabies and anthrax vaccines
• Koch's Postulates

  1. A particular microbe must be found in all cases of the disease and must not be present in healthy animals or humans.
  2. The microbe must be isolated from the diseased animal or human and grown in pure culture in the laboratory.
  3. The same disease must be produced when microbes from the pure culture are inoculated into healthy susceptible laboratory animals.
  4. The same microbe must be recovered from the experimentally infected animals and grown again in pure culture.
• Koch's Postulates, cont.

  • If an organism fulfills Koch's postulates, it has been proven to be the cause of that particular infectious disease
  • Koch's Postulates helped prove the germ theory of disease
  • Koch gave a tremendous boost to the development of microbiology by stressing laboratory culture and identification of microorganisms
  • Circumstances do exist in which Koch's Postulates cannot be fulfilled
• Pathogens cause two categories of diseases: infectious diseases and microbial intoxications
• Opportunistic pathogens are microbes that can cause disease, but usually do not; they can be thought of as microbes that are awaiting the opportunity to cause disease

   

   
• Some members of our indigenous microflora are opportunistic pathogens
• The use of microbes to clean up toxic wastes and other industrial waste products is known as bioremediation

   
• Saprophytes are organisms that live on dead and/or decaying organic matter

   
• Microorganisms are involved in the decomposition of dead organisms and waste products
• Microorganisms play significant roles in our lives;
• For many years, microorganisms have been used as"cell models"; the more that scientists learned about microbial cells, the more they learned about cells in general
• Microbes that live in the intestinal tracts of animals aid in the digestion of food and produce beneficial substances
• Algae and bacteria serve as food for tiny animals; they are important links in food chains

   
• Louis Pasteur (1822-1895)

   

  French chemist who made numerous contributions to microbiology

   
• Louis Pasteur (1822-1895)

   

  -Investigated different fermentation products

  -Developed the pasteurization process

  -Discovered life forms that could exist without oxygen (anaerobes)

  -Developed several vaccines, including rabies and anthrax vaccines

    
• anton von leeuwenhoek was the first to observe microorganisms with a microscope
• Anton van Leewenhoek is known as the father of microbiology and the microscope due to his early study of bacteria. He was a Dutch scientist. Antonie Van Leeuwenhoek a Dutch, who saw microbes when he was polishing lens he saw microbes.