2.2 What are antibiotics?

Activity 7: What are antibiotics?

Watch Video 5, on antibiotics:

Download this video clip.Video player: Video 5
Copy this transcript to the clipboard
Print this transcript
Show transcript|Hide transcript

Transcript: Video 5

NARRATOR:
Microbes, mostly tiny bacteria, make up around 90% of the cells in a typical human body and 10% of our body weight. Most of them are in our gut and on our skin. Many microbes are beneficial, for example, helping us to digest our food. Only a tiny fraction cause disease, and are usually kept in check by our immune system. But when they aren't, microbes also help us to fight back.
Bacteria cause disease when they are able to reproduce in the body. They produce harmful substances called toxins, which damage tissues and organs. But in nature, microbes can also produce agents called antibiotics to protect themselves against competitors.
PROFESSOR CHARLES COCKELL:
It's a tough world out there. And you might think that you just see competition in the savannas of Africa. But in fact, the microbes fight each other as well. And in fact, like martial arts, they have ways of fighting other microbes with particular moves. And one move they have is to produce antibiotics. These are compounds that allow them to kill other microbes and take all the food for themselves, all the resources that they need. And so the competition between microbes results in these very sophisticated antibiotic molecules.
End transcript: Video 5
Download
Video 5
Interactive feature not available in single page view (see it in standard view).

Now write down in your own words a definition of antibiotics.

Discussion

Compounds that are made by microbes to fight other microbes are naturally occurring antibiotics. Scientists have copied and often modified these compounds to use to fight bacteria in humans, animals and plants.

Activity 8: Study definitions

In this course you have already seen a few concepts, and you have read about microbes, bacteria, antibiotics and antimicrobials. Take a few minutes to study the definitions listed in the table below and then answer the questions that follow.

TermDefinition
AntibacterialCompounds that kill or inhibit the growth of bacteria.
AntibioticCompounds that kill or inhibit the growth of microbes/micro-organisms. ‘An antibiotic is an agent or substance that is produced by or derived from a micro-organism that kills or inhibits the growth of another living micro-organism. Antibiotic substances that are synthetic, semi-synthetic, or derived from plants or animals are, strictly speaking, not antibiotics. However, for the purposes of this module they are included. In this document “antibiotic” refers to an antimicrobial agent with the ability to kill or inhibit bacterial growth.’ (WHO, 2019)
AntifungalCompounds that kill or inhibit the growth of fungi.
AntimicrobialCompounds that kill or inhibit the growth of microbes/micro-organisms. ‘An antimicrobial is an agent or substance derived from any source (micro-organisms, plants, animals, synthetic or semi-synthetic) that acts against any type of micro-organism, such as bacteria (antibacterial), mycobacteria (anti-mycobacterial), fungi (antifungal), parasite (anti-parasitic) and viruses (antiviral).’ (WHO, 2019)
AntiparasiticCompounds that kill or inhibit the growth of parasites.
AntiviralCompounds that kill or inhibit the growth of viruses.

a. 

True


b. 

False


The correct answer is a.

Answer

Antibacterials are a kind of antimicrobial.

a. 

True


b. 

False


The correct answer is b.

Answer

Antimicrobials also include antifungals, antivirals and antiparasitics.

Note: because this course mostly focuses on bacterial antimicrobial resistance, we will generally use the terms ‘antibiotic’ and ‘antimicrobial’ to mean ‘antibacterial’.

2.1 What bacteria are

2.3 What antibiotics do