Organized in an A-to-Z format, this reference guide is designed to help users find their way in the vast--and sometimes bewildering--world of living things too small to be discerned with the naked eye. Entries cover environmental, industrial, and food microbiology, in addition to the microbiology of health and disease. Scientific techniques used for studying microorganisms are discussed, and biographies of key individuals are provided. A chronology of infections and disease epidemics from 430 BC to the present is included as an appendix.