What is antibiotic?

Antibiotics are chemicals that kill or inhibit the growth of bacteria and are used to treat bacterial infections. They are produced in nature by soil bacteria and fungi. This gives the microbe an advantage when competing for food and water and other limited resources in a particular habitat, as the antibiotic kills off their competition.

How do antibiotics work?

Antibiotics take advantage of the difference between the structure of the bacterial cell and the host’s  cell.

They either prevent the bacterial cells from multiplying so that the bacterial population remains the same, allowing the host’s defense mechanism to fight the infection or kill the bacteria, for example stopping the mechanism responsible for building their cell walls.

An antibiotic can also be classified according to the range of pathogens against which it is effective. Penicillin G will destroy only a few species of bacteria and is known as a narrow spectrum antibiotic. Tetracycline is effective against a wide range of organisms and is known as a broad spectrum antibiotic.