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Dental caries in the Syrian hamster—IX

1962; Elsevier BV; Volume: 7; Issue: 3 Linguagem: Inglês

10.1016/0003-9969(62)90017-1

1879-1506

Paul H. Keyes, R.J. Fitzgerald,

Oral microbiology and periodontitis research

Streptomycin-resistant streptococci were developed from parent cariogenic strains isolated from a carious lesion in a hamster. These so-called “labelled” streptoccci are also cariogenic and are readily recovered and identified on selective culture media containing streptomycin, but they induce caries considerably more slowly than the parent strains or natural infection. To enhance caries activity and still have the advantages of labelled cariogenic organisms, attempts were made to implant a streptomycin resistant mutant strain (HSR-6) into the mouths of hamsters which harboured other cariogenic organisms. Recoveries, however, were only sporadically successful. This result has been attributed, at least in part, to competition between closely related strains for establishment within the oral microbial ecology. Yet, in a few cases the streptomycin-resistant mutant strain successfully established itself in association with other cariogenic forms, and several females which maintained the labelled streptococci passed them to succeeding generations. In addition this report shows again that caries can be induced in albino hamsters by the inoculation of pure cultures of certain streptococci, or by a flora passed from dam to offspring, or by direct transmission from cage mates. Many caries assays require not only a study of the activity of the disease but also a method for assessing associated microbiological conditions. These studies point the way toward more refined microbic evaluations in conventionally maintained laboratory animals.