Arguments against the replacement of type species of the genus Salmonella from Salmonella choleraesuis to 'Salmonella enterica' and the creation of the term 'neotype species', and for conservation of Salmonella choleraesuis

This taxonomic note argues against proposals to replace Salmonella choleraesuis as the type species of the genus Salmonella with 'Salmonella enterica'. Yabuuchi and Ezaki contend that such replacement violates Rule 20a of the Bacteriological Code (1990 Revision) and reject the introduction of the term 'neotype species' as unsupported by the Code. They note that S. choleraesuis was properly designated as the type species according to established rules and appears in the Approved Lists of Bacterial Names. The authors argue that the similarity between the specific epithet 'choleraesuis' and the serovar name 'Choleraesuis' does not justify changing the type species designation. While 'S. enterica' has gained widespread use among bacteriologists despite its illegitimate status, the authors maintain that formal rules must be followed. They request that the Judicial Commission reject 'Salmonella enterica' and conserve S. choleraesuis as the type species. To resolve nomenclatural confusion arising from the naming similarity, they recommend renaming the serovar from Choleraesuis to Hogcholera, which falls outside Code regulations as an infrasubspecific category.

Key findings

• Salmonella choleraesuis is the legitimate type species of genus Salmonella according to Rule 20a of the Bacteriological Code and Opinion 26 of the Judicial Commission
• Proposals by Le Minor and Popoff (1987) and Euzéby (1999) to designate 'Salmonella enterica' as the type species violate the Bacteriological Code and lack Judicial Commission approval
• The term 'neotype species' introduced in recent proposals has no definition or description in the Bacteriological Code
• To reduce confusion from the similar names of the specific epithet and serovar, the authors recommend changing the serovar name from Choleraesuis to Hogcholera