To keep the many organisms on earth straight, in the 18th century the Swedish botanist Carl Linnaeus developed a simple nomenclature system to classify and name all organisms including bacteria. This system ranks all organisms using the following headings, shown with the example of the bacterium E. coli.
Domain: Bacteria
Phylum: Proteobacteria
Class: Gammaproteobacteria
Order: Enterobacteriales (Order names always end in –iales.)
Family: Enterobacteriaceae (Family names always end in –aceae.)
Genus: Escherichia
Species: coli
Organisms are uniquely identified by the genus and species names, which are always either italicized or underlined, the genus is often shortened to the first letter (for example, E. coli).
