Our body is not just human cells, it also contains bacteria ! Furthermore in very large amount. Indeed, there are more than 100 000 billion in the human body.

By the way, what are bacteria?

They are living, unicellular microorganisms belonging to the empire of prokaryotic, which means that bacteria do not have nucleus.

The bacterial genetic material, consisting of DNA, is in the form of a single chromosome and possibly, plasmids.

How do we name them?

Their nomenclature is in latin, like the other alive organisms. They are mainly identified by their genus and species’ name and more specifically by their strain name.

How can we classify them?

They are  classified and identified according to various parameters :

  • their microscopic morphology (cocci, bacilli, isolated, in necklaces)
  • the composition of their cellular wall (type Gram + or Gram -)
  • their respiratory type (aerobic, strict anaerobic, optional aero-anaerobic)
  • their substratum needs
  • their glucose degradation pathway (respiration or fermentation)

Bacteria can be also classified according to their capacity to form a spore : this state allows them to survive in extreme conditions (heat, desiccation) for millions of years!

Bacteria = diseases?

For a long time considered to be only pathogenic in the same way as viruses, some bacteria are beneficial for your health. For example, probiotics.

The World Health Organization (WHO) even recognized them with an official definition!




Picture: Freepik