What is binomial nomenclature?

All living organisms have two names (binomial) to describe them: a genus (generic name for a group of closely related organisms) and a species (specific name that distinguishes individual types within the group). Knapp et al6 nicely summarised the origins of the system, which were invented by Carl Linnæus, a Swedish botanist in the 18th century. Linnæus suggested two-word ‘nomina trivialia’ to make it easier to remember the names of organisms, which were originally descriptive phrases (‘nomina specifica’) that changed as knowledge accrued. The rules for nomenclature have changed over time and differences between zoology, botany and microbiology have emerged.6

Bacteria

Bacteria have names in Latin. All bacteria are named in five taxonomic categories: class, order, family, genus and species. The genus and species form the binomial that we use to identify the organism (table 1). The name of the genus can come from the person who discovered it, for example, Neisseria, from Albert Neisser, or a characteristic of the organism, for example, Chlamydia, which is Greek for a cloak and describes its intracellular nature. The genus might have more than one distinct species. For example, many species of Neisseria colonise humans and animals, but only two are human pathogens (N. gonorrhoeae and N. meningitidis).7 Sometimes, the species can be divided into subspecies. For example, we use the binomial Treponema pallidum to refer to the sexually transmitted infection syphilis, but there are three subspecies: T. pallidum subspecies pallidum causes syphilis; T. pallidum subsp. pertenue causes yaws; and T. pallidum subsp. endemicum causes bejel.8 Chlamydia is a bacterium with a contentious taxonomic history, having been called Miyaganawella, Bedsonia and Rakeia in the past,9 and having initially been thought to be a virus10 or a protozoan.11

Viruses

Virologists have adopted different criteria for nomenclature, partly because viruses are not living organisms.12 Viruses often have names in English, for example hepatitis B virus, but they can also have Latin names, for example herpes simplex virus (herpes comes from the Greek herpein, to creep). The generic names of viruses such as HIV are not written in italics; italics are only used for the virus species name or its family. They are not capitalised unless the name is a proper noun, for example Ebola virus.

Whose responsibility is it to get the name right?

Authors probably expect copy editors to correct their spelling and editors expect authors to proofread carefully. As our published examples show, failures at both stages result in errors in the printed version. But getting to print is the end of a long process and editors and reviewers will read a manuscript before it is accepted. Authors are responsible for checking their spelling and terminology before submitting a manuscript. First impressions are important so it makes sense to get the spelling and formatting right before submission.

Advice for authors

Editors and production staff at Sexually Transmitted Infections have come up with some guidance for authors (tables 1, 2 and 3). This combines published conventions for scientific nomenclature, summarised by the journal Emerging Infectious Diseases,13 and the opinions of the editors. We try to cover spelling and abbreviations of both organisms and conditions for the most common sexually transmitted infections (table 2).

We have posted the guidance in our Instructions for Authors on the submission website (http://sti.bmj.com/site/about/guidelines.xhtml) and we hope you find it useful. Please follow our guidance for all your future submissions.

Answer: all are incorrect (see table 2 for the correct spelling).