ABSTRACT
The shift toward economic and political globalization accompanied by greatly increased travel contributes to the spread of disease from one region. Microbes are free-living, predominantly single cell organisms that are ubiquitous in nature. One ounce of rich garden soil may contain 60 billion living organisms; yet only about ten percent of the over 2000 identified species of bacteria are known to cause disease. Most microorganisms are unicellular and have the ability to grow very rapidly in number as well as in size of an individual cell under ideal growth conditions. The size of an organism strongly affects dispersability and transmission of diseases in both air and water. Most bacteria consist of about eighty percent water and twenty percent solids and they require moisture to grow. As with all living organisms, bacteria must absorb nutrients, metabolize them in order to derive energy to synthesize new cell structure and then excrete the by-products of metabolism.
