Salmonella nomenclature

Salmonella nomenclature is complex, and scientists use different systems to refer to and communicate about this genus. However, uniformity in Salmonella nomenclature is necessary for communication between scientists, health officials, and the public. Unfortunately, current usage often combines several nomenclatural systems that inconsistently divide the genus into species, subspecies, subgenera, groups, subgroups, and serotypes (serovars), and this causes confusion. CDC receives many inquiries concerning the appropriate Salmonella nomenclature for the reporting of results and for use in scientific publications. The defining development in Salmonella taxonomy occurred in 1973 when Crosa et al. demonstrated by DNA-DNA hybridization that all serotypes and subgenera I, II, and IV of Salmonella and all serotypes of 'Arizona' were related at the species level; thus, they belonged in a single specie. In 1986 the Subcommittee of Enterobacteriaceae of the International Committee on Systematic Bacteriology at the XIV International Congress of Microbiology unanimously recommended that the type species for Salmonella be changed to S. enterica, a name coined by Kauffmann and Edwards in 1952, because no serotype shares this name. Nonetheless, the request was denied by the Judicial Commission. Although the Judicial Commission was generally in favor of S. enterica as the type species of Salmonella, its members believed that the status of Salmonella serotype Typhi, the causative agent of typhoid fever, was not adequately addressed in this request for an opinion.