BASIC MICROBIOLOGY

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BASIC MICROBIOLOGY
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Definition

• Microbiology is the science that studies living
  organisms that cannot be seen with the naked eye
  (microorganisms or microbes)

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Nature of Microorganisms

• Most microorganisms are harmless, some are
  beneficial and others harmful (pathogenic)
  causing disease
• eg. E. coli from the colon (breaks down
  waste/makes vitamin K) can enter the urinary
  tract and cause an infection

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Types of Microorganisms

• Major types are
• Bacteria
• Fungi
• Protozoa (protists, parasites)
• Viruses

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Transmission or Spread of Microorganisms

• Vectors usually an animal or insect that
  carries the microorganism
• Airborne - spread through the air by people's
  coughing and sneezing
• Direct contact - an infected person touching a
  surface and then another person touching that
  surface
• Fecal-oral - contaminated hands, food and water
• Sexually Transmitted direct transfer of bodily
  fluids (blood, semen)

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Transmission or Spread of Microorganisms
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Bacteria

• most familiar of the microbes that infect humans
• classified by their shape and arrangement

Type Shape Arrangement
Diplococci Round in pairs
Staphylococci Round in groups or clusters
Streptococci Round in chains
Bacilli Rod-shaped in pairs, single, or in chains
Spirilli Cork-screw or spiral single
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Bacterial Resistance

• What is the proper way to take your antibiotics?
• Why are you not prescribed antiobiotics every
  time that you have some type of flu or cold
  symptoms?
• What is MRSA?
• What are nosocomial infections?

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Fungi

• Once classified as plants but they dont undergo
  photosynthesis
• Saprophytes feed on dead or decaying material
• Thrive in moist environments
• Examples (mould, mildew, yeast)
• Cause some diseases in humans
• Ringworm
• Athletes foot
• Thrush
• Poisonous

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Ringworm

• Skin infection causing severe itching (scalp,
  groin, beard)
• If left untreated can be passed on to others by
  direct or indirect contact, infected wrestling
  mats
• Treated with fungicides, antifungal creams

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Athletes Foot

• Related to dirty showers and running shoes
• Moist area between toes

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Thrush yeast infection
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Protists (Protozoa)

• Also known as parasites
• Mostly unicellular
• Eukaryotes
• Thrive in moist environments
• Cause disease in humans
• Malaria
• Food poisoning
• Leishmaniasis
• Trypanosomiasis

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Disease from Protists

• Malaria
• https//www.youtube.com/watch?vIVbq2yQH52g
• Food poisoning
• https//www.youtube.com/watch?vjlvXtvWm80A
• Leishmaniasis
• https//www.youtube.com/watch?vJR44Y0wUaX0
• Trypanosomiasis
• https//www.youtube.com/watch?v4aVUrGO97Zg

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Viruses

• A virus is a microorganism that reproduces inside
  the cells of living hosts
• viruses attach to and enter the host cell and
  force the cell into making more viruses
• Viruses can cause diseases in humans (HIV, common
  cold, Zika, Ebola)
• Death of the host cell leads to symptoms
• Some viruses remain dormant in the body for long
  periods without symptoms (herpes, chicken pox
  virus)
• Viruses are usually completely eliminated by a
  healthy immune system,
• Antibiotics have no effect on viruses,
• Vaccines that produce lifelong immunity can
  prevent some viral infections.