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PubMed · 5551636

Genetic heterogeneity in Streptococcus mutans.

A L Coykendall
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Abstract

The genetic homogeneity among eight cariogenic strains of Streptococcus mutans was assessed by deoxyribonucleic acid (DNA)-DNA reassociation experiments. DNA species were extracted from strains GS5, Ingbritt, 10449, FAl, BHT, E49, SLl, and KlR. Labeled DNA ((14)C-DNA) was extracted from strains 10449, FAl, and SLl. Denatured (14)C-DNA fragments were allowed to reassociate, i.e., form hybrid duplexes, with denatured DNA immobilized on membrane filters incubated in 0.45 m NaCl-0.045 m sodium citrate at 67 or 75 C. At 67 C, 10449 (14)C-DNA reassociated extensively only with GS5 and Ingbritt DNA. FAl (14)C-DNA hybridized extensively only with BHT DNA, and SLl (14)C-DNA reassociated with KlR and E49 DNA. DNA which hybridized extensively at 67 C also reassociated to a high degree at 75 C. Thermal elution of (14)C-FAl-BHT duplexes showed that the hybrid duplexes were thermostable. The results indicate that S. mutans is a genetically heterogeneous species. The strains studied can be divided into three (possibly four) genetic groups, and these groups closely parallel antigenic groups.

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Carbon IsotopesChemical PrecipitationCulture MediaDNA, BacterialEthanolFiltrationGenetics, MicrobialHot TemperatureHybridization, GeneticNucleic Acid DenaturationSerotypingSodiumSolventsStreptococcusSulfatesSurface-Active AgentsJournal Article

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A L Coykendall. 1971. Genetic heterogeneity in Streptococcus mutans.. https://doi.org/10.1128/jb.106.1.192-196.1971

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