Writing about biology and other scientific topics involves navigating and communicating the complexity and diversity of living organisms.
How can we ensure that the features of these organisms are conveyed clearly? An important first step is to understand nomenclature, the branch of taxonomy designed to bring a sense of order and organization when naming living organisms.
We will highlight a few principles and examples of nomenclature by providing examples of microorganisms such as pathogenic bacteria and fungi.
The species of these microorganisms have Latin (or latinized) binomial names composed of a genus name and a specific epithet. The genus name is always a noun and always begins with a capital letter. The specific epithet is usually an adjective and always begins with a lowercase letter. In text, binomial names should be either italicized or underlined.
Once the complete name of a microorganism has been written out once, the genus can be abbreviated to just the capital letter, if no other genus in the publication begins with the same letter. For example, the pathogenic bacterium Streptococcus pneumoniae can be written as S. pneumoniae the second time it is mentioned in an article, if no other genus in the paper begins with the letter “S”. In a publication’s abstract or summary, the name of the microorganism should always be spelled out.
When referring to a single unnamed species, the genus name is followed by “sp.”, (for example, Staphylococcus sp.), while when referring to multiple unnamed species, the genus name is followed by “spp.”, (for example, Bacillus spp.). When writing about multiple species that belong to the same genus, that specific genus can be spelled out once, even if the other species have not been mentioned earlier in the text. For example, for the pathogenic fungus Aspergillus spp., individual species can be listed as Aspergillus fumigatus, A. flavus, and A. terreus.
Would you like to learn more?
The CDC provides an extensive description of scientific nomenclature for microorganisms, genes, and proteins, among other categories. Read more here.
The International Committee of Systematics in Prokaryotics (ICSP) oversees the nomenclature of prokaryotic organisms, such as bacteria, fungi, and parasites. Visit the site here.