In the presence of amino sugars D-glucosamine and D-galactosamine no spontaneous competence could be observed in the highly transformable R6bd strain of Pneumococcus or it was decreased by several orders of magnitude. The highest inhibition of competence was detected when the amino sugar at a concentration 5 mg/ml of the medium was added not only to the transformation but also to the pretransformation medium. After a 150 min growth in the transformation medium in the presence of the amino sugar a 3--4-fold greater number of cells (as a viable count) could be detected as compared with the control without the amino sugar. It was found microscopically that the amino sugar prevents natural agglutination, which normally occurs in the competent culture. The role of specific amino sugar determinants for binding of the competence factor on the cell surface and the resulting inhibitory effect of these sugars on the development of competence are discussed.

• MeSH
• Agglutination drug effects   MeSH
• Amino Sugars pharmacology   MeSH
• Depression, Chemical MeSH
• DNA, Bacterial MeSH
• Galactosamine pharmacology   MeSH
• Glucosamine pharmacology   MeSH
• Mannose MeSH
• Stereoisomerism MeSH
• Streptococcus pneumoniae drug effects   immunology   MeSH
• Transformation, Genetic drug effects   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Amino Sugars MeSH
• DNA, Bacterial MeSH
• Galactosamine MeSH
• Glucosamine MeSH
• Mannose MeSH

• MeSH
• Drug Resistance, Microbial * MeSH
• Time Factors MeSH
• Cells, Cultured * MeSH
• Spheroplasts drug effects   MeSH
• Streptococcus pneumoniae drug effects   MeSH
• Streptomycin pharmacology   MeSH
• Sulfanilamides pharmacology   MeSH
• Transformation, Genetic * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Streptomycin MeSH
• Sulfanilamides MeSH

• MeSH
• Drug Resistance, Microbial MeSH
• RNA, Bacterial pharmacology   MeSH
• Potassium Chloride pharmacology   MeSH
• Deoxyribonucleases antagonists & inhibitors   metabolism   MeSH
• Hypertonic Solutions pharmacology   MeSH
• Kinetics MeSH
• Recombination, Genetic MeSH
• RNA, Transfer pharmacology   MeSH
• Streptococcus pneumoniae enzymology   MeSH
• Streptomycin MeSH
• Sulfanilamides MeSH
• Transformation, Genetic * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Bacterial MeSH
• Potassium Chloride MeSH
• Deoxyribonucleases MeSH
• Hypertonic Solutions MeSH
• RNA, Transfer MeSH
• Streptomycin MeSH
• Sulfanilamides MeSH

• Keywords
• CHLORIDES *, DIPLOCOCCUS PNEUMONIAE *, DNA, BACTERIAL *, DRUG RESISTANCE, MICROBIAL *, POTASSIUM *, STREPTOMYCIN *,
• MeSH
• Drug Resistance, Microbial * MeSH
• Chlorides * MeSH
• Diploidy * MeSH
• DNA, Bacterial * MeSH
• DNA * MeSH
• Potassium * MeSH
• Drug Resistance * MeSH
• Streptococcus pneumoniae * MeSH
• Streptomycin * MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Chlorides * MeSH
• DNA, Bacterial * MeSH
• DNA * MeSH
• Potassium * MeSH
• Streptomycin * MeSH