Proposal to Elevate the Subspecies of Streptococcus mutans to Species Status, Based on Their Molecular Composition

Publisher Website
Google Scholar
Abstract
It is proposed to confer species rank to the genetically distinct streptococci that have been considered subspecies of Streptococcus mutans Clarke: S. mutans subsp. rattus Coykendall, S. mutans subsp. cricetus Coykendall, and S. mutans subsp. sobrinus Coykendall. S. mutans is defined to exclude phenotypically similar bacteria that have deoxyribonucleic acid (DNA) guanine plus cytosine contents appreciably different from 36 to 38 mol% and/or that do not demonstrate DNA base-sequence homology with the type strain. Streptococci that resemble S. mutans but that are quite disparate in molecular constitution are here regarded as comprising four new species: S. rattus (Coykendall) comb. nov., S. cricetus (Coykendall) comb. nov., S. sobrinus (Coykendall) comb. nov., and S. ferus sp. nov. NCTC 10449 is here designated as the neotype strain of S. mutans. The type strains of S. rattus, S. cricetus, S. sobrinus, and S. ferus are FA1 (= ATCC 19645), HS6 (= ATCC 19642), SL1, and 8S1, respectively. Simple biochemical tests serve to identify most strains of all five species. Serological procedures are capable of differentiating most human isolates.