What Is the Difference Between a Microorganism and a Pathogen?

A microorganism is a living entity that is so small it can only be seen with the aid of a microscope.

microorganism or pathogen

A pathogen is an organism that causes disease. Examples of pathogens include bacteria, viruses, parasites, and fungi. Note that a pathogen does not have to be a microorganism; some parasitic worms cause disease and are pathogens but are large enough to be seen with the naked eye.

In addition, a microorganism is not necessarily a pathogen. Bacteria can only be seen with a microscope, but most bacteria do not cause disease.

All vaccines are targeted against pathogenic bacteria or viruses. We do not (yet) have any vaccines against fungi or parasites.

About Karen Hill

Karen Hill is a freelance writer, editor, and columnist. Born in New York, her work has appeared in the Examiner, Yahoo News, Buzzfeed, among others.

Leave a Comment