MICRO

• Microbiology


  The study of all living organisms that are too small to be visible with the naked eye
• Medical microbiology


  The study of certain classes of viruses, bacteria, fungi and protozoa that can affect health
• Microorganisms are life forms too small to be seen by the unaided human eye. These microscopic organisms are diverse in form and function, and they inhabit every environment on Earth that supports life.
• Parasitology


  The scientific study of parasites, their hosts, and the relationship between the parasite and the host
• Medical parasitology


  Concerned mainly with the larger, usually visible, parasites such as the various worms and ecto parasites
• Bacteria, viruses and protozoa, are so important as to require separate disciplines and are not normally included in medical parasitology
• Anthony Van Leeuwenhoek


  • He is the father of MICROBIOLOGY
  • Dutch microscopist who was the first to observe bacteria and protozoa
  • Amateur Scientist, ground his own lenses and described what we know today as bacteria- rod shaped and spiral shaped (animalcules)
• Louis Pasteur

  • French scientists 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 developed the process called PASTEURIZATION
  • He proved that fermentation was caused by a microbe-YEAST
  • He developed vaccines for rabies and anthrax
• Robert Koch


  • Developed Koch's postulates – important technique for determining the actual microbial cause agent of a disease
  • 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
  • Bacillus anthracis produces spores capable of resisting adverse conditions
  • Developed method of fixing, staining and photographing bacteria
  • Developed methods of cultivating bacteria on solid media
  • Worked on tuberculin which led to the development of a skin test valuable in diagnosing tuberculosis

  
• Koch's and Pasteur's work helped establish the "Germ Theory of Disease" – that microorganisms cause disease (in people, animals, and even plants)

  
• Patrick Manson

  • Father of tropical medicine
  • Notable for transmission vector- Causative agent for FILIARIS (mosquito)
• Charles Louis Alphonse Laveran


  • Determine another blood borne parasites (PLASMODIUM) (malaria)
• Ronald Ross


  • Work in the study of plasmodium
  • Discover the transmission vector of malaria is MOSQUITO
• Pasteur


  Microorganisms not come in non-living organisms
• Spontaneous generation theory

  Microorganisms come from living things (MEAT AND FLIES)
• Pasteur proved he is correct (2000's)
• Example: Rats arise from stored grains
• Koch's postulates


  • Important technique for determining the actual microbial cause agent of a disease

  
• Symbiosis


  A close and long term interaction between organisms
• Competition


  There are limited resources in an ecosystem. Individuals compete for these resources and for space
• Predation


  One organism feeds on another organism. The organism that is eaten is called prey. The organism that is eating is called the predator
• Mutualism


  Both organisms benefit from the relationship
• Commensalism

  One organism benefits from the relationship, the other organism does not benefit but is not harmed
• Parasitism

  One organism benefits from the relationship, the other organism is harmed, but not always killed
• Impacts of microorganisms

  • Act as agent of diseases
  • Agriculture and Nutrition
  • In food
  • In industry- (pharmaceutical and cosmetics)
• Prokaryotic microorganisms include Domain Bacteria and Domain Archaea
• Bacteria and Archaea

  • Prokaryotes
  • Variable morphology; no distinguishable morphologic differences
  • Masters of adaptation
• Differences between Bacteria and Archaea

  • Bacteria are present in all environments that support life, while Archaea are present in the most extreme environments that support life
  • Bacteria have known pathogens or parasites of plants and animals (5%), while Archaea have no known pathogens or parasites of plants or animals
• Cell membrane functions

  • Permeability
  • Anchor proteins for key cell functions
  • Plays major role in energy conservation and consumption
• Cell wall


  Maintains cell shape, protection, and prevention from bursting
• Cell wall classification

  • Gram-positive – contains thick peptidoglycan
  • Gram-negative – contains thin peptidoglycan and an outer membrane
• Outer membrane


  Lipopolysaccharide – contains the antigenic molecules
• Archaeal cell walls

  • Pseudomurein - formed from alternating repeats of N-acetylglucosamine (also present in peptidoglycan) and N-acetyltalosaminuronic acid
  • S layer – para-crystalline surface layer; interlocking molecules of protein or glycoprotein
• Some archaea have different cell wall types and some lack cell wall
• Capsules


  Organized tight matrix, excludes small particles, and is tightly attached
• Slime Layers


  More easily deformed, loosely attached, and does exclude particles
• Fimbrae


  Enable cells to stick to surfaces, including animal tissues in the case of pathogenic bacteria, or to form pellicles or biofilms on solid surfaces
• Pili


  Longer and only one or a few pili are present on the surface of a cell; for conjugation, adhesion
• Endospores


  • Highly differentiated cells that are extremely resistant to heat, harsh chemicals, and radiation
  • Survival structures and enable the organism to endure unfavorable growth conditions
  • Easily dispersed by wind, water, or through the animal gut
  • Dormant stage of a bacterial life cycle
• Nucleoid


  • The genetic material of the chromosome of prokaryotes
  • Not membrane bound