micropara

• Microbiology


  The study of microbes
• 2 Major categories of microbes

  • Acellular microbes (viruses and prions)
  • Cellular microbes (bacteria, archaea, some algae, protozoa, some fungi)
• Microbes are ubiquitous, meaning they are virtually everywhere
• We have, living on and in our bodies, approximately 10 times as many microbes as the total number of cells that make up our bodies (10 trillion cells 10 100 trillion microbes)
• It has been estimated that perhaps as many as 500 to 1,000 different species of microbes live on and in us
• Indigenous microflora (or indigenous microbiota)


  The microbes that live on and in the human body
• Pathogens


  Microbes that cause disease
• Nonpathogens


  Microbes that do not cause disease
• Opportunistic pathogens


  Microbes that usually do not cause problems but have the potential to cause infections if they gain access to a part of the body where they do not belong
• Escherichia coli (E. coli) lives in our intestinal tracts and does not cause us any harm as long as it remains in our intestinal tract, but can cause disease if it gains access to our urinary bladder, bloodstream, or a wound
• Opportunistic pathogens can strike when a person becomes rundown, stressed-out, or debilitated (weakened) as a result of some disease or condition
• Microbes are essential for life on this planet as we know it
• Microbes involved in elemental cycles

  • Carbon
  • Nitrogen
  • Oxygen
  • Sulfur
  • Phosphorus
• Microbes serve as important links in food chains
• Microscopic organisms in the ocean

  • Phytoplankton (tiny marine plants and algae)
  • Zooplankton (tiny marine animals)
• Earth was formed about 4.5 billion years ago and, for the first 800 million to 1 billion years of Earth's existence, there was no life on this planet
• Fossils of primitive microbes (as many as 11 different types) found in ancient rock formations in northwestern Australia date back to about 3.5 billion years ago
• Animals made their appearance on Earth between 900 and 650 million years ago, and humans (Homo sapiens) have existed for only the past 100,000 years or so
• Candidates for the first microbes on Earth are archaea and cyanobacteria
• Earliest known infectious diseases

  • Tuberculosis
  • Syphilis
  • Schistosomiasis
  • Dracunculiasis (guinea worm infection)
  • Tapeworm infections

  
• The earliest known account of a "pestilence" occurred in Egypt about 3180 BC
• Around 1900 BC, near the end of the Trojan War, the Greek army was decimated by an epidemic of what is thought to have been bubonic plague
• The Ebers papyrus, describing epidemic fevers, was discovered in a tomb in Thebes, Egypt and was written around 1500 BC
• A disease thought to be smallpox occurred in China around 1122 BC
• Epidemics of plague occurred in Rome in 790, 710, and 640 BC and in Greece around 430 BC
• Other early infectious diseases

  • Rabies
  • Anthrax
  • Dysentery
  • Smallpox
  • Ergotism
  • Botulism
  • Measles
  • Typhoid fever
  • Typhus fever
  • Diphtheria
  • Syphilis
• Syphilis


  The name syphilis was not given to the disease until 1530
• Other names for syphilis

  • Neapolitan Disease (French)
  • French or Spanish Disease (Italian)
  • Rench Pox (English)
  • Spanish, German, Polish, Turkish Pocks
• Career fields within the science of microbiology

  • Bacteriologist
  • Phycologists or Algologist
  • Protozoologist
  • Mycologist
  • Virologist
• Clinical microbiology or diagnostic microbiology


  A branch of medical microbiology concerned with the laboratory diagnosis of infectious diseases of humans
• Anton van Leeuwenhoek


  The first person to see live bacteria and protozoa, referred to as the "Father of Microbiology", the "Father of Bacteriology", and the "Father of Protozoology"
• Leeuwenhoek was not a trained scientist, but a fabric merchant, a surveyor, a wine assayer, and a minor city official in Delft, Holland
• For more than 2 centuries, from 1650 to 1850, the theory of spontaneous generation was debated and tested
• Louis Pasteur and John Tyndall finally disproved the theory of spontaneous generation and proved that life can only arise from preexisting life
• Theory of biogenesis


  The theory that life can only arise from preexisting life, first proposed by Rudolf Virchow in 1858
• Louis Pasteur


  A French chemist who made numerous contributions to the newly emerging field of microbiology, considered by many to be the foundation of the science of microbiology and a cornerstone of modern medicine
• Pasteur discovered what occurs during alcoholic fermentation and demonstrated that different types of microbes produce different fermentation products
• Pasteur dealt the fatal blow to the theory of spontaneous generation
• Aerobes


  Organisms that require oxygen
• Anaerobes


  Organisms that do not require oxygen