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Biomedical subjects

J M Tanzer

Publications and source records attributed to J M Tanzer.

At least 55 records · Page 3Linked to original sources
PubMed1982

Preemption of Streptococcus mutans 10449S colonization by its mutant 805.

Oral infection of rats with Streptococcus mutans mutant 805 was used to prevent the establishment of its highly virulent wild-type progenitor NCTC 10449S. The dose of wild-type cells required to colonize 100% of the specific pathogen-free Osborne-Mendel rats (21 to 43 days old) consuming caries test diet 2000 was greater than 4 x 10(5) but less than 4 x 10(6) cells. Therefore, the latter dose was used to challenge rats which had already been colonized by an oral dose of about 6 x 10(8) cells of mutant 805. This prior infection by 805 either completely protected rats from subsequent colonization by wild-type cells or greatly delayed and diminished their emergence. Rats in which wild-type cells became established showed much lower percentages of wild-type cells in their total recoverable floras than did rats that were not first infected by the mutant. Large doses of mutant 805, however, did not displace wild-type cells from rats once it became established. There was no evidence of reversion of the mutant, which is defective in intracellular polysaccharide synthesis and hence is less virulent than wild-type cells. The data indicate that the S. mutans cell which first colonizes rats gains the strongest ecological position and is difficult to displace. Also, they suggest the possible prophylactic utility of infection by this mutant of S. mutans.

Animals↗
PubMed1982

Predominant microflora associated with human dental periapical abscesses.

The microflora of periapical abscesses of teeth free of periodontal disease was studied. Permucosal aspiration of abscess contents and anaerobic cultural, microscopic, and biochemical techniques indicated a mixed but somewhat specific and relatively limited facultative and obligate anaerobic flora with Fusobacterium nucleatum and Streptococcus mitis as a frequent pair.

Adult↗
PubMed1981

Pemphigus-like mucosal lesions: a side effect of penicillamine therapy.

A patient with Wilson's disease on long-term penicillamine therapy was seen for evaluation and management of chronic persistent debilitating stomatitis, which was subsequently determined to be cytologically and histologically consistent with pemphigus vulgaris. A brief review of the pertinent literature disclosed that the dermatologic lesions of pemphigus secondary to penicillamine are alleviated by discontinuation of penicillamine and institution of prednisone therapy. Our patient's primarily oral lesions did not resolve with this recommended alteration in therapy, since penicillamine could be discontinued only briefly in the interest of maintaining acceptable serum copper levels and because of the paucity of available alternative copper-chelating agents. Eventually the patient was placed on tetraethylene tetramine (TETA), an experimental copper-chelating agent, and betamethasone (Celestone). This has provided a satisfactory reduction in serum copper levels and resolution of the oral lesions.

Adult↗
PubMed1980

Effect of growth conditions on sucrose phosphotransferase activity of Streptococcus mutans.

Sucrose and glucose phosphoenolpyruvate-dependent phosphotransferase (PTS) activities were studied in growing cultures of Streptococcus mutans serotype c and d/g cells adapted to either glucose or sucrose. Both acid production and optical absorbance were used to monitor growth in pH-controlled defined growth medium. The sucrose PTS activity appeared to be significant only under conditions of substrate limitation or slow growth as a result of low environmental pH. However, under environmental conditions which permitted rapid growth sucrose PTS activity appeared to be repressed, and only when the cells approached substrate-limited stationary phase after growth on high sucrose-supplemented medium was significant sucrose PTS activity again observed. A mutant apparently defective in sucrose PTS activity grew rapidly and produced acid under conditions of high environmental sucrose level but showed no sucrose PTS activity when the culture approached stationary phase. The mutant, however, after adaptation to glucose, demonstrated significant glucose PTS once the culture had attained the stationary growth phase. During diauxie growth in the presence of glucose and sucrose, there were sequential apparent inductions and repressions of glucose and sucrose PTS activities corresponding to decreases and increases of growth rate on the two substrates. Thus, S. mutans possesses at least two transport mechanisms for each substrate studied. One system (PTS) functions under conditions permitting slow growth and another functions under conditions permitting rapid growth.

Enzyme Induction↗
PubMed1980

Statistical relationship of morsal to bucco-lingual, approximal and sulcal caries in rats.

The correlation of morsal with sulcal, bucco-lingual and approximal caries scores of rats was compared. The morsal and bucco-lingual plus approximal correlation was significantly better than the morsal with sulcal correlation. When reporting rat caries, sulcal scores should be reported alone; morsal scores should be grouped with bucco-lingual and approximal to demonstrate total smooth surface lesions.

Animals↗
PubMed1979

In vitro evaluation of seven cationic detergents as antiplaque agents.

The bactericidal efficacy of seven cationic detergents was studied in vitro against intact performed plaques of representative strains of four oral dental plaque-forming microorganisms: Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indexes of antiplaque activity were established. Only cetyltrimethylammonium bromide was more efficacious than the reference agent, the bisbiguanide chlorhexidine, for the apparently more potent tooth-adherent cariogenic and periodontopathic elements, respectively, of the in vivo plaque microflora, S. mutans and A. viscosus.

Actinomyces↗
PubMed1979

Phosphoenolpyruvate-dependent sucrose phosphotransferase activity in Streptococcus mutans NCTC 10449.

A phosphoenolpyruvate-dependent sucrose phosphotransferase system (PTS) has been demonstrated, by an enzyme-coupled reaction and product isolation, in decryptified cell suspensions of the cariogenic microorganism Streptococcus mutans NCTC 10449. The apparent sucrose PTS reaction for sucrose-adapted, sucrose-challenged cells displayed saturation kinetics with an apparent Km of 7.14 x 10(-5) M, which was distinct from the Km of the glucose PTS activity of glucose-adapted, glucose-challenged cells. Both the sucrose and the glucose PTS activities appear to be inducible and under separate genetic control. The sucrose PTS reaction demonstrated in decryptified cells had an absolute requirement for phosphoenolpyruvate. Only 2-phosphoglycerate, the immediate glycolytic precursor of phosphoenolpyruvate, was found to substitute for phosphoenolpyruvate in this reaction in the absence of fluoride. The sucrose PTS activity of sucrose-adapted cells was competitively inhibited by raffinose and lactose; these same sugars had no effect on the apparent glucose PTS activity. Fructose was the only carbohydrate tested other than sucrose which elicited an apparent PTS reaction in sucrose-adapted cells. The product of the sucrose PTS reaction was isolated and behaved chromatographically on a Dowex-1-X8 column like a monophosphate ester. Alkaline phosphatase treatment of the presumptive sucrose monophosphate liberated a component which behaved chromatographically like free sucrose. Subsequent acid hydrolysis of this component produced moieties which behaved chromatographically like glucose and fructose.

Enzyme Induction↗
PubMed1979

Essential dependence of smooth surface caries on, and augmentation of fissure caries by, sucrose and Streptococcus mutans infection.

Streptococcus mutans-free Osborne-Mendel rats were used to study the ability of well-characterized S. mutans strains of Bratthall serotypes c, d, and E to form plaque and cause caries when the animals consumed either sucrose- or glucose-containing diets. All of the serotype representatives successfully infected, colonized, and emerged in the oral ecology of animals, independent of the carbohydrate supplementation of the diet. However, the sucrose-containing diet supported higher percentages of S. mutans of all the serotypes in the plaque and greater amounts of plaque on the teeth. Smooth surface caries was essentially S. mutans dependent and sucrose dependent; fissure caries, although it was neither dependent on S. mutans infection nor sucrose consumption, was augmented by both. This sucrose-associated emergence of all three serotype representatives in the plaque flora and their virulence in the production of caries can be ascribed to their production of alkali-solible alpha-(1 yields 3)-rich glucans from sucrose.

Animals↗
PubMed1979

Statistical relationship of morsal to bucco-lingual, approximal and sulcal caries in rats.

The correlation of morsal with sulcal, bucco-lingual and approximal caries scores of rats was compared. The morsal with bucco-lingual plus approximal correlation was significantly better than the morsal with sulcal correlation. When reporting rat caries, sulcal scores should be reported alone; morsal scores should be grouped with bucco-lingual and approximal to demonstrate total smooth surface lesions.

Animals↗
PubMed1978

Genetic alterations of Streptococcus mutans' virulence.

The use of mutants defective in caries-associated traits has enabled the genetic dissociation of agglutination from adhesion, the demonstration of serotype-specific contributions of IPS to virulence, the importance of glucanohydrolase to virulence to a greater degree than to plaque formation, and the apparent lack of importance of agglutination to virulence. We have also been able to demonstrate the ability of plaque formation-defective mutants and other variants both to infect and to emerge, yet not to cause disease. Additional mutants, currently under study in our laboratory include fructanase, invertase, and sucrose permease-defectives. Ultimately, the identification of key, probably surface-associated virulence factors will offer more potent and specific antigens for directed immune responses by the host.

Adhesiveness↗
PubMed1978

In vitro colonization of Streptococcus mutans on enamel.

An in vitro model consisting of enamel from extracted human molars, suspended from wires in inoculated culture tubes, was used to study the adhesion of bacteria to enamel. Under conditions in which there was no macroscopically visible plaque formation, electron micrographs showed no bacterial deposits on the enamel surface. In samples where Streptococcus mutans attached to enamel, an extracellular, pellicle-like material was associated with the bacteria adjacent to the enamel. This material appeared to bind to the enamel surface and to mediate bacterial attachment. Membrane-filtered (Millipore Corp.) saliva deposited a thin surface layer on the enamel, but there were no observable alterations of S. mutans attachment to enamel pretreated with saliva. It was noted that Bratthall serotype c and e strains of S. mutans, when grown in glucose-containing medium, attached, although less tenaciously, to enamel and nichrome wires. Chemical and gas chromatographic analyses of cell-associated materials formed by serotype c and e strains cultured in glucose-containing medium revealed low amounts of glucose-positive material and no polymer linkages characteristic of glucan; yet the same strains cultured in sucrose-containing medium had relatively high amounts of glucose-positive material, with polymer linkages-characteristic of glucan. Serotype a, b, and d strains could attach only in sucrose-containing media.

Dental Enamel↗
PubMed1978

Selective medium for isolation of Eikenella corrodens from periodontal lesions.

The addition of 5 microgram of clindamycin per ml to a modified Todd-Hewitt growth medium permitted the ready enumeration of Eikenella corrodens from deep periodontal lesions because it allowed differential growth amongst the periodontal pocket gram-negative microaerophilic-anaerobic flora, maximized the numbers of E. corrodens in such culture, and inhibited the growth of most of the other confounding microorganisms.

Bacteroides↗