New method for the isolation of Streptococcus mutans and its differentiation from other oral streptococci

Publisher Website
Google Scholar
Abstract
A new, improved agar medium for the isolation of S. mutans, the etiological agent of [human] dental caries, was developed. Unlike mitis-salivarius agar, this medium recovers a greater number of S. mutans strains from most oral specimens and, because of its mannitol and sorbitol content, it also facilitates the differentiation of S. mutans from other oral streptococci, e.g., S. salivarius, S. mitis and S. sanguis, which do not grow or produce scanty growth only after 10 days of incubation. The medium is easy to prepare because of its simple and unique composition, is characterized by the presence of an acid indicator, and can also be utilized under aerobic and anaerobic conditions. The medium cannot be used to distinguish among the 8 serotypes, a to g and SL-1, of S. mutans. Mannitol-utilizing bacteria such as streptococci (e.g., S. faecalis) and other microorganisms (e.g., Staphylococcus aureus) can grow on this medium and can be distinguished from S. mutans by their unique colony morphology.