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Biomedical subjects

C Mouton

Publications and source records attributed to C Mouton.

At least 91 records · Page 5Linked to original sources
PubMed1984

[Susceptibility of potential periodontopathic bacteria to metronidazole, spiramycin and their combination].

A total of 65 bacterial strains originating mostly from subgingival plaque were tested for their susceptibilities to metronidazole, spiramycin, and their combination, ornidazole, erythromycin and tetracycline by means of an agar dilution technique. All agents were active against all anaerobic Gram-negative rods. Bacteroides gingivalis and Fusobacterium nucleatum showed marked susceptibility to metronidazole (MIC less than or equal to 0.06 microgram/ml) whereas 4-64 micrograms/ml were required to inhibit the capnophilic Actinobacillus actinomycetemcomitans and Capnocytophaga. Gram-positive facultatives were resistant to nitro-imidazoles but were inhibited at macrolide concentrations less than or equal to 0.5 microgram/ml. Except for F. nucleatum and Veillonella strains (2 less than or equal to MIC less than or equal to 128 micrograms/ml) macrolides were active against all other anaerobic bacteria tested. At concentrations less than or equal to 2 micrograms/ml the combination of spiramycin and metronidazole (2 : 1) was active against virtually all bacteria tested but our results failed to show a synergistic effect.

Bacteria↗
PubMed1983

Effect of xylitol on the growth and glycolysis of acidogenic oral bacteria.

We investigated the effect of xylitol on the growth of different oral bacteria in the presence of glucose. Xylitol inhibited the growth of all but one of ten strains of S. mutans and failed to inhibit the growth of the lactobacilli, actinomycetes, and other streptococci tested except S. sanguis 10556, which was slightly inhibited. However, the rate of acid production of the sensitive S. mutans strains was not equally affected by xylitol. These data, obtained with pure cultures of acidogenic oral bacteria, may explain the lack of an in vitro inhibitory effect of xylitol on dental plaque samples.

Acids↗
PubMed1981

Serum antibodies to oral Bacteroides asaccharolyticus (Bacteroides gingivalis): relationship to age and periondontal disease.

An enzyme-linked immunosorbent assay microplate method was used for measuring levels of antibody specific for the oral serotype of Bacteroides asaccharolyticus (Bacteroides gingivalis) in serum samples obtained from umbilical cords, infants, children, periodontally normal adults, and edentulous adults. Serum from patients with various periodontal diseases, including adult periodontitis, localized juvenile periodontitis, generalized juvenile periodontitis, post-localized juvenile periodontitis, and acute necrotizing ulcerative gingivitis, were also studied. A positive correlation between increase in age and increase in both prevalence and level of specific antibody in the G, A, and M classes of immunoglobulins was observed. This indicates that antibodies reactive with oral B. asaccharolyticus found in up to 84% of normal adults are natural antibodies, presumably with a protective role. Among the patient groups, those with adult periodontitis were found to have levels of immunoglobulin G antibodies to oral B. asaccharolyticus that were five times higher than the antibody levels found in control subjects. The levels of IgG antibodies to this organism in the other patient groups were comparable to the levels found in the control group. However, 50% of the individuals in the generalized juvenile periodontitis group had high levels of immunoglobulin G antibodies to B. asaccharolyticus, suggesting heterogeneity with respect to immune response in these patients. These results indicate that antibodies to oral B. asaccharolyticus (B. gingivalis) occur at low levels in most normal children and adults and that the rise in titer of the specific antibodies of each major class of immunoglobulins parallels the ontogenic change in serum levels of that isotype. In contrast, there is a marked increase in titer of immunoglobulin G antibodies to oral B. asaccharolyticus in the group of patients with adult periodontitis and in patients with the generalized form of juvenile periodontitis.

Adult↗
PubMed1981

Eubacterium saburreum and Veillonella parvula: a symbiotic association or oral strains.

A cocci-filament association was discovered in bacterial cultural studies of a subgingival plaque sample. Components were isolated and identified as Veillonella parvula and Eubacterium saburreum. A E. saburreum cell-associated material consisting of approximately 25% glucose and 70% protein was found which may play a role in the adherence of V. parvula to this filament. Acid end product analysis via gas liquid chromatography showed an uptake of lactic and succinic acids by V. parvula resulting in increased levels of acetic, propionic and n-butyric acids in mixed culture of the E. saburreum and the V. parvula strains. The ability of E. saburreum to adhere to nichrome wire and to glass surfaces as well as the secondary plaque forming ability of V. parvula indicates that these organisms may play a role in the maturation of human dental plaque.

Dental Plaque↗
PubMed1980

Characterization of tufted streptococci isolated from the "corn cob" configuration of human dental plaque.

Streptococci isolated from "corn cob" configurations of human dental plaque possess a polar fibrillar tuft extending 100 to 150 nm from one pole of the cell. The two strains studied were physiologically related to the Streptococcus sanguis-Streptococcus mitior group and were most similar to Streptococcus mitis ATCC 903. The corn cob streptococci were serologically related to S. sanguis serotype 1. The polar tuft contained at least two antigenically distinct components, one serologically related to the glycerol phosphate backbone of teichoic acid. The other was an electrophoretically slow-moving antigen similar to a component of S. mitis ATCC 903. It is suggested that the corn cob streptococci in vivo adhere to Bacterionema matruchotii by means of the polar tuft.

Animals↗
PubMed1980

Antigenic studies of oral and nonoral black-pigmented Bacteroides strains.

Antigens of several oral and nonoral strains of Bacteroides asaccharolyticus (proposed classification of oral B. asaccharolyticus, Bacteroides gingivalis), Bacteroides melaninogenicus subsp. intermedius, B. melaninogenicus subsp. melaninogenicus, and B. melaninogenicus subsp. levii were identified in soluble preparations obtained by sonication, autoclaving, and NaOH treatment of whole bacterial cells. The sonicate preparations contained the most complete representation of soluble antigens using antisera to the whole organism in gel precipitation tests. Among strains of B. melaninogenicus subsp. intermedius many common antigens were detected, and no consistent antigenic differences were seen between strains from oral and nonoral sites. None of the antigens of B. melaninogenicus subsp. intermedius reacted with sera raised to several strains of oral or nonoral B. asaccharolyticus, nor did antigens prepared from the latter strains react with antisera to B. melaninogenicus subsp. intermedius. At least one common antigen was shared by strains of B. melaninogenicus subsp. intermedius and strains of B. melaninogenicus subsp. melaninogenicus; however, subspecies-specific antigens were also found. Antigens from and antisera to oral and nonoral strains of B. asaccharolyticus did not react with sera to and antigens from B. melaninogenicus subsp. melaninogenicus. Strains of B. asaccharolyticus isolated from the oral cavity were antigenically distinct from strains of B. asaccharolyticus obtained from nonoral sites and lesions. This lack of cross-reactivity between the oral and nonoral strains of B. asaccharolyticus together with recent findings of marked genetic differences between oral and nonoral strains of B. asaccharolyticus suggest that these groups of organisms may represent different species.

Antigens, Bacterial↗
PubMed1980

Evaluation of Fluoretec-M for detection of oral strains of Bacteroides asaccharolyticus and Bacteroides melaninogenicus.

Fluoretec-M is a polyvalent conjugate used in direct fluorescent-antibody staining for identification of the Bacteroides asaccharolyticus-Bacteroides melaninogenicus group. The Fluoretec-M reagent detected all oral and nonoral test strains of B. melaninogaenicus subsp. intermedius, all test strains of B. melaninogenicus subsp. melaninogenicus, and the nonoral strains of B. asaccharolyticus. However, the Fluoretec-M polyvalent reagent and the monovalent conjugates which constitute Fluoretec-M did not detect the oral strains B. asaccharolyticus. The use of Fluoretec-M can therefore generate false-negative results in studies of specimens from oral cavity and from nonoral sites in which an infection with B. asacacharolyticus of oral origin may have taken place. It is suggested that antibodies reactive with the oral antigenic type of B. asaccharolyticus be included in the preparative procedure of the Fluoretec-M reagent.

Bacteroides↗
PubMed1977

Combined micromanipulation, culture and immunofluorescent techniques for isolation of the coccal organisms comprising the "corn cob" configuration of human dental plaque.

The present study describes methods to 1) selectively isolate Corn Cob Configurations (CCC) from dental plaque by micromanipulation; 2) obtain pure cultures of the coccal constituent; 3) determine by immunofluorescent procedure which organisms originated from the CCC. Using a de Fonbrune micromanipulator, CCC specimens were isolated from supragingival plaque samples. The viability of one specimen thus obtained was established by observing growth on a slide culture. One set of CCC specimens was transferred to broth and incubated aerobically immediately upon collection. Another set was transferred to prereduced transport medium and later plated on blood agar for aerobic and anaerobic culturing. A total of 10 coccal strains were thus isolated. Antisera produced in rabbits against the 10 strains were used to localize these coccal organisms on plaque smears by using the indirect fluorescent antibody technique. Of the 10 antisera tested, 2 produced against streptococcal strains consistently gave a positive immunofluorescent reaction with the coccal component of CCC in the plaque smears; the corresponding streptococci were therefore considered to be CCC forming strains in vivo.

Bacteria↗
PubMed1975

Effect on plaque of a xylitol-containing chewing-gum. A pilot study.

The effects on plaque induced by the use of xylitol- and sucrose-containing chewing-gums were studied on ten test-persons with neglected oral hygiene during two three-day periods. The chewing of three, as well as of ten pieces per day of a xylitol chewing-gum resulted in a significantly reduction in the amount of plaque and in the decrease of activity of invertase-like enzymes in plaque extracellular phase, when compared to corresponding conditions where a sucrose-containing chewing-gum was used.

Chewing Gum↗
PubMed1975

Effect on plaque of a xylitol-containing chewing-gum. A clinical and biochemical study.

The effects on plaque induced by single or repeated use of xylitol- and sucrose-containing chewing-gums were studied on twenty subjects refraining from tooth-brushing for three days. Mechanical removal of plaque by chewing during a single period was shown to yield no significant differences between gravimetric values obtained before and after chewing. Daily use of a xylitol-containing chewing-gum reduced by 47% the weight of plaque formed in comparison to a sucrose-containing product, and by 20--41% in comparison to conditions when no chewing-gum was used. The use of a xylitol chewing-gum induced a lower invertase-like activity in plaque extra cellular phase. Results at variance with the gravimetric data were obtained by using a stained plaque scoring system; the eventual inadequacy of such plaque scoring systems was discussed.

Adolescent↗
PubMed1975

Effect of a xylitol chewing gum on plaque quantity and quality.

The aim of the present study was to further investigate the plaque-reducing effect of a xylitol-containing chewing gum. Ninety-six dental students were divided randomly into three groups: a sucrose group (n = 32), a xylitol group (n = 36) and a control group (n = 28), using a sucrose-containing chewing gum, a xylitol-containing chewing gum, or no chewing gum, respectively, during a three-day experimental plaque growth period with restricted oral hygiene. The fresh weight of plaque collected in the xylitol group was 40% lower than in the sucrose group, along with a significantly lower mean plaque index. The use of the xylitol chewing gum induced low invertase-like activity in plaque extra-cellular phase together with low carbohydrate content. These results concur to indicate advantageous effects through the use of a xylitol-containing chewing gum.

Adult↗
PubMedDate not supplied

Communication of preferences for care among human immunodeficiency virus-infected patients. Barriers to informed decisions?

OBJECTIVE: To examine the way patients with serious, progressive illnesses communicate their care preferences to their physician. DESIGN: An observational, cross-sectional survey of 1031 clients with acquired immunodeficiency syndrome (AIDS) or symptomatic human immunodeficiency virus disease. Self-report of communication was assessed in 861 clients who stated a treatment preference focused on extending life or focused on comfort even if it shortened life. SETTING: The Robert Wood Johnson AIDS Health Services Program in 9 US cities. PARTICIPANTS: Eight hundred sixty-one of 1031 clients recruited to the AIDS Health Services Program. RESULTS: Eight hundred sixty-one subjects expressed a preferred treatment approach; however, only 35.8% had spoken to their physician about their preferred treatment. Black clients were half as likely (odds ratio, 0.49; confidence interval, 0.29-0.85) to have discussed their preferred treatment approach even after adjustment for age, function, education, income, and other covariates. Black clients were half as likely to prefer an approach to care that focused only on comfort (odds ratio, 0.51; 95% confidence interval, 0.34-0.76). Clients with AIDS who were symptomatic daily, college educated, and more functionally impaired were more likely to have discussed a preferred treatment approach with their physician. CONCLUSIONS: Most persons with symptomatic human immunodeficiency virus infection have not discussed their preferred treatment approach with a physician. This disparity is greater for blacks, who were less likely to want a palliative treatment approach.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Phenotypic characterization of human and animal biotypes within the species Porphyromonas gingivalis.

Ninety-nine strains of Gram-negative black-pigmented anaerobic rods, grown on Todd-Hewitt blood agar plates, were identified and characterized according to a typing scheme including UV fluorescence, catalase, trypsin-like and haemagglutinating activities, biochemical tests with the ATB 32A kit, and gas-liquid chromatography. To determine the taxonomic position of the Porphyromonas gingivalis biotypes, 68 strains (31 of human origin and 37 of animal origin) were compared to 31 strains of closely related species or of uncertain generic status. Most animal strains were isolated in our laboratory by subculturing samples from the oral cavity of five mammalian species (bear, cat, coyote, dog and wolf). Those strains differed from human P. gingivalis strains in that they were positive for catalase, beta-galactosidase and glutamyl-glutamic acid arylamidase; from Bacteroides macacae by more rapid pigmentation, positive haemagglutination, failure to produce propionic acid, and negative alpha-galactosidase; and from Bacteroides salivosus by more rapid pigmentation, positive haemagglutination and failure to produce propionic acid. These data demonstrate that phenotypic heterogeneity within the taxon P. gingivalis can be resolved into two biotypes, each corresponding to a human source or an animal source.

Animals↗
PubMedDate not supplied

Randomly amplified polymorphic DNA analysis confirms the biotyping scheme of Porphyromonas gingivalis.

The application of the arbitrarily primed PCR (AP-PCR) procedure to generate randomly amplified polymorphic DNA (RAPD) fingerprints for the study of the taxon Porphyromonas gingivalis was investigated. Nine human strains and seven animal strains of P. gingivalis as well as eighteen strains other than P. gingivalis were analysed. Four nanomer primers of random sequence were evaluated for their ability to distinguish genetic diversity. Three primers generated RAPD fingerprints that allowed the sixteen strains to be differentiated; two of the primers yielded species-specific markers, and two of the primers permitted biotype distinction. Cluster analysis of the RAPD fingerprints revealed two major phenetic groups that matched the human and animal biotypes. Our results indicate that AP-PCR (i) can generate strain-specific fingerprints, (ii) confirms genetic heterogeneity and the biotype grouping of the P. gingivalis taxon, and (iii) enables identification of potential genetic markers at the species, biotype and subtype levels and is thus a promising tool for bacterial systematics. Our results also underline the potential of AP-PCR for epidemiological studies of periodontal pathogens.

Animals↗
PubMedDate not supplied

Genetic relatedness between oral and intestinal isolates of Porphyromonas endodontalis by analysis of random amplified polymorphic DNA.

Genomic fingerprints from the DNA of 27 strains of Porphyromonas endodontalis from diverse clinical and geographic origins were generated as random amplified polymorphic DNA (RAPD) using the technique of PCR amplification with a single primer of arbitrary sequence. Cluster analysis of the combined RAPD data obtained with three selected 9- or 10-mer-long primers identified 25 distinct RAPD types which clustered as three main groups identifying three genogroups. Genogroups I and II included exclusively P. endodontalis isolates of oral origin, while 7/9 human intestinal strains of genogroup III which linked at a similarity level of 52% constituted the most homogeneous group in our study. Genotypic diversity within P. endodontalis, as shown by RAPD analysis, suggests that the taxon is composed of two oral genogroups and one intestinal genogroup. This hypothesis remains to be confirmed.

Animals↗