The nomenclature of bacteria is regulated by the rules of the International Code of Nomenclature of Bacteria which was revised in 1975 and the revised code was updated in 1992. The code presents the formal framework by which bacteria are to be officially named, and the procedures by which existing names can be changed for example, when new data warrants taxonomic rearrangement.
In code, there are even rules for rejecting names if errors were made in the original naming process or a name has otherwise become invalid. The code covers the rules for the naming of all species, genera, families, and orders of bacteria.
It was Carl Linnaeus who first introduced binomial nomenclature in 1753 for plants and animals and later the same system was adopted to name bacteria also.
Following the binomial system of nomenclature, bacteria are given genus names and species epithets. The generic name is a Latinized noun starting with a capital letter and the specific epithet, which is always written in small hand, is generally a Latinized adjective qualifying the genus name.
For example, over hundred species of genus Bacillus have been described including Bacillus subtilis, B. cereus, and B. megaterium. These species epithets mean “slender”, “waxen”, and “big beast” respectively, and refer to key morphological, physiological, or ecological traits characteristic of each organism.
As an international convention, the generic name and species epithet should be printed in italics but when they are written by hand they should be underlined. Care must be taken while abbreviating the genera that share the same initial letter.
In this condition, the first few letters of the generic name are written. For example, Staphylococcus aureus is abbreviated as Staph aureus and Streptococcus pyogenes as Strepto pyogenes. Care must also be taken when the bacteria are referred to as a group. In this case their names should be neither capitalized nor underlined (e.g., staphylococci).
The abbreviation “sp.’ (singular) or “spp.” (pleural) should be used when the species is not specified. However, the family names should have the ending -aceae (e.g., family Enterobacteriaceae), whereas the order names should have the endings -ales (e.g., order Eubacteriales). The order and family names should be capitalized.
The International Code of Nomenclature of Bacteria requires that when a new bacterium is isolated and thought to be either new species of an existing genus or a new genus, its detailed description and the proposed name should be published in the International Journal of Systematic Bacteriology which paves the way for its inclusion in the Validation Lists published in the Bergey’s Manual of Systematic Bacteriology, a major taxonomic treatment of bacteria.
The names in the Validation Lists of Bergey’s Manual are valid in the sense of being validly published and widely circulated as the Manual is widely used and is a compendium of information on all recognized species of bacteria.