bacterium

A bacterium is a tiny living thing that is so small you can only see it with a microscope.

Bacteria are single-celled organisms, which means they are made up of just one cell. They are found everywhere in the world, including in your body.

Some bacteria are helpful, such as the bacteria that live in your gut and help you digest food. Other bacteria can cause diseases, such as strep throat or food poisoning.

Bacteria can reproduce very quickly, which is why they can sometimes cause infections. However, there are also many ways to prevent and treat bacterial infections.

The doctor diagnosed the patient with a bacterial infection.