Research Rack: Glossary

bacterium - any of a group of single-celled microorganisms that live in soil, water, organic matter, or the bodies of plants and animals and are important because of their chemical effects and as a cause of disease.

disease - an abnormal bodily condition of a living plant or animal that interferes with functioning and can usually be recognized by signs, symptoms, and illness.

E. coli O157:H7 - one of hundreds of strains of the bacterium Escherichia coli. Although most strains are harmless and live in the intestines of healthy humans and animals, this strain produces a powerful toxin and can cause severe illness.

epidemiology - a branch of medical science that deals with the occurrence, distribution, and control of disease in a population

immune system - the interacting combination of all the body’s ways of recognizing cells, tissues, objects, and organisms that are not part of itself, and which initiates the immune response to fight them.

Influenza - also known as the flu, is a contagious disease that is caused by the influenza virus. It attacks the respiratory tract in humans (nose, throat, and lungs).

microorganism - an organism (as a bacterium) of microscopic or less than microscopic size.

virus - any of a large group of very tiny infectious agents that are too small to be seen with the ordinary light microscope but can often be seen with the electron microscope, that are considered either very simple microorganisms or very complicated molecules, that have an outside coat of protein around a core of RNA or DNA, that can grow and multiply only in living cells, and that cause important diseases in human beings, lower animals, and plants.

vaccine - a preparation of killed, weakened, or fully infectious microbes that is given (as by injection) to produce or increase immunity to a particular disease.