C1 ppt

• Microbiology


  The study of microorganisms, including bacteria, archaea, fungi, protozoa, and viruses

  
• Parasitology


  The study of parasites and parasitic diseases
• Microorganisms


  Also called microbes, they include tiny animals, fungi, algae, and single-celled protozoa
• Antoni van Leeuwenhoek


  • Began making and using simple microscopes
  • Often made a new microscope for each specimen
  • Examined water and visualized tiny animals, fungi, algae, and single-celled protozoa: "animalcules"
• Microorganisms


  By the end of the 19th century, they were called microorganisms; now they are also called microbes
• Leeuwenhoek's microscope


  • Lens
  • Specimen holder
• Taxonomy


  A system for naming and grouping similar organisms together
• Categories of microorganisms


  • Bacteria
  • Archaea
  • Fungi
  • Protozoa
  • Algae
  • Small multicellular animals
• Bacteria and Archaea


  • Prokaryotic (lack nuclei)
  • Much smaller than eukaryotes
  • Found everywhere there is sufficient moisture; some have been isolated from extreme environments
  • Reproduce asexually
  • Bacterial cell walls contain peptidoglycan; some lack cell walls
  • Archaeal cell walls are composed of polymers other than peptidoglycan
• Fungi


  • Eukaryotic (have membrane-bound nucleus)
  • Obtain food from other organisms
  • Possess cell walls
  • Include molds - multicellular, grow as long filaments, reproduce by sexual and asexual spores
  • Include yeasts - unicellular, reproduce asexually by budding, some produce sexual spores
• Protozoa


  • Single-celled eukaryotes
  • Similar to animals in nutrient needs and cellular structure
  • Live freely in water; some live in animal hosts
  • Asexual (most) and sexual reproduction
  • Most are capable of locomotion by pseudopods, cilia, or flagella
• Algae


  • Unicellular or multicellular
  • Photosynthetic
  • Simple reproductive structures
  • Categorized on the basis of pigmentation and composition of cell wall
  • Scientists and manufacturers use many algae-derived products

  
• Other organisms of importance to microbiologists

  • Parasites
  • Viruses
• Parasites and viruses are also studied by microbiologists
• Spontaneous generation


  The idea that living things can arise from nonliving matter
• Redi's experiments


  Showed that maggots did not develop in decaying meat that was kept isolated from flies, but did develop in meat exposed to flies
• Needham's experiments


  Reinforced the idea that microbes could arise spontaneously in beef gravy and plant infusions
• Spallanzani's experiments


  Contradicted Needham's findings, concluding that microorganisms exist in air and can contaminate experiments, and that spontaneous generation of microorganisms does not occur

  
• Pasteur's experiments


  • Performed investigations of spontaneous generation
  • When the "swan-necked" flasks remained upright, no microbial growth appeared
  • When the flask was tilted, dust from the bend in the neck seeped back into the flask and made the infusion cloudy with microbes within a day

  
• Scientific method


  Observation leads to question, question generates hypothesis, hypothesis is tested through experiment(s), results prove or disprove hypothesis, accepted hypothesis can lead to theory/law, disproved hypothesis is rejected or modified
• Fermentation


  The process by which microorganisms convert carbohydrates to alcohols and carbon dioxide
• Pasteur's experiments on fermentation

  • Led to the development of pasteurization, a process of heating liquids just enough to kill most bacteria
  • Began the field of industrial microbiology, the intentional use of microbes for manufacturing products

  
• Buchner's experiments


  Demonstrated that fermentation does not require living cells, and showed that enzymes promote chemical reactions, beginning the field of biochemistry
• Germ theory of disease

  The theory developed by Pasteur that certain diseases are caused by the presence and actions of specific microorganisms
• Robert Koch's studies on disease causation

  • Examined colonies of microorganisms
  • Studied anthrax
• Koch's experiments led to the development of Koch's postulates, a set of criteria for determining the cause of a particular disease
• Fermentation


  The process that causes fermentation
• Pasteur's experiments


  1. Led to the development of pasteurization

  2. Process of heating liquids just enough to kill most bacteria

  3. Began the field of industrial microbiology

  4. Intentional use of microbes for manufacturing products

  
• Buchner's experiments


  1. Demonstrated fermentation does not require living cells

  2. Showed enzymes promote chemical reactions

  3. Began the field of biochemistry
• Germ theory of disease

  Pasteur's theory that microorganisms cause disease
• Robert Koch


  • Studied disease causation (etiology)
  • Examined colonies of microorganisms
• Koch's experiments


  1. Simple staining techniques

  2. First photomicrograph of bacteria

  3. First photomicrograph of bacteria in diseased tissue

  4. Techniques for estimating CFU/ml

  5. Use of steam to sterilize media

  6. Use of Petri dishes

  7. Techniques to transfer bacteria

  8. Bacteria as distinct species
• Koch's postulates


  • Suspected causative agent must be found in every case of the disease and be absent from healthy hosts
  • Agent must be isolated and grown outside the host
  • When agent is introduced into a healthy, susceptible host, the host must get the disease
  • Same agent must be found in the diseased experimental host
• Gram staining


  Technique to differentiate between gram-positive and gram-negative bacteria
• Semmelweis and handwashing


  1. Ignaz Semmelweis required medical students to wash their hands in chlorinated lime water

  2. Resulted in higher patient survival rates
• Lister's antiseptic technique


  1. Joseph Lister advanced antisepsis in health care settings

  2. Sprayed wounds, surgical incisions, and dressings with carbolic acid (phenol)
• Nightingale and nursing


  1. Florence Nightingale introduced cleanliness and antiseptic techniques into nursing practice

  2. Advocated for hospital and public health policy reform
• Snow and epidemiology


  1. John Snow mapped cholera epidemic in London in 1854

  2. His work was the foundation for infection control and epidemiology
• Jenner's vaccine


  1. Edward Jenner developed a vaccine against smallpox

  2. Demonstrated the validity of vaccination

  3. Began the field of immunology
• Ehrlich's "magic bullets"


  1. Paul Ehrlich worked to identify "magic bullets" that would destroy pathogens but not harm humans

  2. Discoveries began the field of chemotherapy