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S Araya

Publications and source records attributed to S Araya.

At least 37 records · Page 2Linked to original sources

Bacteriophage deoxyribonucleic acid-induced mutation of Streptococcus mutans.

A cariogenic strain, Streptococcus mutans PK 1, has been demonstrated to have prophage by observation of phage particles with an electron microscope and by induction with mitomycin C. The phage particles could not be detected in a mutant strain which lost the characteristic adhesive nature on glass surfaces and exhibited diminished ability to synthesize insoluble polysaccharide. By infecting the mutant cells with the phages or with free phage deoxyribonucleic acid isolated from the parent strain of S. mutans PK1, the mutant cells were transformed to the cariogenic strain with adhesive nature. The transformants retained the general characteristics of S. mutans PK 1, but in addition all transformants showed a new character; namely, the transformant cell could produce ammonia from arginine, whereas neither the parent nor mutant strains of S. mutans PK 1 had such a property;

Ammonia↗

Transfection of Streptococcus sanguis by phage deoxyribonucleic acid isolated from Streptococcus mutans.

Streptococcus sanguis ATCC 10556 cells were infected with free phage DNA of S, mutans strain PK 1. Two transformants were isolated which made colonies with large mucoid forms on mitis-salivarius agar. Both transformants had an increased ability to synthesize insoluble glucan and showed an adhesive nature on glass surfaces. These characteristics of the transformants bear a resemblance to S. mutans. These transformants had many physiological characteristics by which they could be recognized as S. sanguis. However, they resembled S. salivarius in forming a large amount of soluble fructan. Furthermore, the transformant cells did not produce ammonia from arginine, whereas their parent cells did.

Bacteriolysis↗