Recommended minimal standards for description of new staphylococcal species

In accordance with Recommendation 30b of the International Code of Nomencla ture of Bacteria, minimal standards are proposed for the genus Staphylococc us and the description of newly recognized species in this genus. Assignmen t of a strain to the genus Staphylococcus requires that it is a Grampositiv e coccus that forms clusters, produces catalase, has an appropriate cell wa ll structure (including peptidoglycan type and teichoic acid presence) and G+C content of DNA in a range of 30-40 mol%. The recommended minimal standa rds for describing a new Staphylococcus species are based on the results of phenotypic and genomic studies of at least five independently isolated str ains. They include colony morphology and the results of the following conve ntional tests: pigment production, growth requirements, fermentative and ox idative activity on carbohydrates, novobiocin susceptibility, enzymic activ ities (nitrate reductase, alkaline phosphatase, arginine dihydrolase, ornit hine decarboxylase, urease, cytochrome oxidase, staphylocoagulase in rabbit plasma, heat-stable nuclease, amidases, oxidases, clumping factor, and hae molytic activity on sheep or bovine blood agar). DNA-DNA hybridization expe riments may distinguish species when the difference between the binding in the homologous reaction and the binding in the heterologous reaction expres sed as a percentage is less than 70%. In addition, rRNA signature sequence criteria, ribotyping characterization of the nomenclature type strain and o ther strains of the species, and reference strains of other species is reco mmended to describe the strains of the new species with sets of genetic att ributes and reveal possible grouping errors. This proposal has been endorse d by the members of the Subcommittee on the taxonomy of staphylococci and s treptococci of the International Committee on Systematic Bacteriology.