WHAT ARE MICRO-ORGANISMS?

Microorganisms are organisms of microscopic size, which may exist in their single-celled form or as a colony of cells

we have bacteria, fungi, protozoa (single-celled eukaryotes) and single-celled Algae. Little multicellular organisms like nematodes and flatworms.

• Viruses aren’t living organisms → no independent reproduction, no metabolism. (They are studied in microbiology so we will also see the viral infection in one of the next chapters.)

  -side note- A lot of them use warm-blooded animals like a human as habitat → symbiosis

• symbiosis = long-term biological interaction between two different organisms

  • commensalism: only the micro-organism gets the advantage

    example: bacteria on our skin that doesn’t bother us. They find organic substances and can live at a constant temperature.

  • mutualism: both the human and the microorganism get an advantage

    For example: intestinal bacteria take nutrients from our intestines and produce vitamin K for the human → essential for blood clotting

  • parasitism: the micro-organism gets the advantage and the human gets the disadvantage example: a cold virus causes an inflammation of the nasal mucosa resulting in an overproduction of nasal mucus

TERMINOLOGY

• Contamination = when someone comes into contact with a pathogen, one speaks of contamination. A disease is called contagious if it can be transmitted by one microorganism to another carrier.

• Infection = if the microorganism begins to multiply and thereby damages the tissue, you speak of an infection. An infection can result in an inflammation, a reaction of the body

• Incubation period = the incubation period is the time between contamination and the first symptoms (noticeable signs of disease)

• Epidemic = if many people have an infectious disease at the same time, you speak of an epidemic. For some infectious diseases, there is a reporting obligation to prevent epidemics

• Pandemic = a worldwide epidemic

  • It is a new disease within the population

  • It infects people and causes serious complaints

  • A simple spread of said disease