What bacteria make you sick?

Bacteria are one-celled organisms visible only with a microscope. You can find them in the air, on food, plants and animals, in the soil, in the water, and on just about every other surface - including your own body. Pathogenic bacteria, the harmful kind, enter the human body from the air, water or food. Once inside, these bacteria attach themselves to or invade specific cells in our respiratory system, digestive tract or any open wound. There they begin to reproduce and spread while using the human body as a source of their own nutrients and energy.