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Biomedical subjects

S S Socransky

Publications and source records attributed to S S Socransky.

At least 109 records · Page 6Linked to original sources
PubMed1990

Amino acid utilization by Fusobacterium nucleatum grown in a chemically defined medium.

The present investigation evaluated amino acid utilization by 120 strains of Fusobacterium nucleatum in a chemically defined medium and attempted to relate the patterns to 3 proposed subspecies of F. nucleatum. Strains were inoculated into a chemically defined medium, with and without 2 g/l glucose, consisting of 14 inorganic salts, 21 amino acids, 23 vitamins and cofactors, and 7 purines and pyrimidines. After 7 days of anaerobic incubation, the spent culture medium, as well as the uninoculated control medium, were analyzed for amino acid content by ion chromatography. Amino acid utilization was determined by the differences in concentrations of amino acids found in inoculated and uninoculated samples. If greater than 34% of the amino acid was removed from the medium, the amino acid was considered to be utilized. Of the 21 amino acids present in the chemically defined medium, 8 amino acids, lysine, glutamine, asparagine, histidine, threonine, serine, glutamate and cysteine were consistently utilized. Four amino acids, tyrosine, tryptophan, methionine and aspartate were utilized by some strains but not others. Nine amino acids, alanine, leucine, isoleucine, glycine, valine, phenylalanine, proline, ornithine, and arginine were not utilized by any of the strains. The utilization patterns did not relate to subspecies formed on the basis of SDS-PAGE and DNA hybridization.

Amino Acids↗
PubMed1990

Development of a diagnostic test for anaerobic periodontal infections based on plaque hydrolysis of benzoyl-DL-arginine-naphthylamide.

Treponema denticola, Porphyromonas (Bacteroides) gingivalis, and Bacteroides forsythus are among the anaerobic species frequently associated with adult forms of periodontal disease. These organisms hydrolyze the synthetic peptide benzoyl-DL-arginine-naphthylamide (BANA), and such enzyme activity can be detected in the plaque and related to clinical disease and the presence of spirochetes. In this investigation, the liquid BANA assay was compared with a commercially developed BANA assay which employed a paper format and which could be read after a 15-min incubation. In the paper format, strips of a Whatman filter paper were impregnated with BANA and strips of nitrocellulose paper were impregnated with fast black K salt. Both strips were applied lengthwise across a paper card (3 by 5 in. [7.6 by 12.7 cm]). The BANA strip at the bottom was inoculated with the test sample (pure culture, plaque), folded back so that it contacted the fast black strip, and then incubated for 15 min at 55 degrees C. T. denticola, P. gingivalis, and B. forsythus always gave a positive reaction, whereas 51 other plaque species were always negative. Six Bacteroides and Capnocytophaga species on occasion had weak reactions. The proportional agreement between BANA positiveness and clinical disease was similar for both the liquid and the paper assays. The sensitivity, specificity, and accuracy relative to the clinical standard of the liquid assay were 74, 76, and 77%, respectively, while those of the paper assay were 81, 78, and 80%, respectively. The paper assay was significantly associated with the presence of either T. denticola or P. gingivalis or both in the plaque samples, with a sensitivity of 85%, a specificity of 53%, and an accuracy of 79%. These findings indicate that a rapid paper assay for BANA hydrolysis gives data comparable to those obtained with the liquid BANA assay.

Arginine↗
PubMed1990

Limit of resolution of flow cytometry for the detection of selected bacterial species.

The enumeration of bacteria in dental plaque samples is a vital but time-consuming procedure that uses standard cultural methods. Flow cytometry has proven to be a useful tool for the analysis of eukaryotic cells. In the present investigation, the utility of this technology for the enumeration of bacteria in mixtures was explored. Rabbit antisera were produced against the putative periodontal pathogens A. actinomycetemcomitans, B. intermedius, B. gingivalis, E. corrodens, W. recta, B. forsythus, as well as the frequently isolated supragingival species S. sanguis. Cross-reactive antibodies were removed by absorption, and the specificity of each antiserum was confirmed by being tested against a panel of 235 oral microbial strains (79 genera; 94 species) by means of ELISA. Conditions were established for the indirect immunofluorescent labeling of cells without agglutination with use of a goat anti-rabbit Ig-FITC second antibody. When an internal bead standard was used, it was found that unstained bacteria were enumerated by light-scattering parameters with poor efficiency (less than 3%). However, cells exposed to FITC either in the presence of specific or non-specific first antibody were enumerated with high efficiency (102.6 +/- 29.3%), indicating that a small amount of non-specific binding of fluorochrome facilitates bacterial detection. Clear discrimination between specifically- and non-specifically-stained bacteria was achieved with all six rabbit antisera. Mixtures of known composition were made (1) with pure cultures or (2) with a known species and supragingival plaque devoid of that species by culture. The results from both approaches with various species combinations revealed that the limit of resolution for accurate quantitation of a selected species was approximately 5%, although specific organisms could be detected qualitatively when present at approximately 1%.

Bacteria↗
PubMed1989

Comparison of two methods for the small-scale extraction of DNA from subgingival microorganisms.

Two methods were compared for the extraction of DNA from small numbers of bacterial cells. The first method involved lysis of cells with SDS in the presence of proteinase K, treatment with hexadecyltrimethyl ammonium bromide (CTAB) and precipitation of DNA with isopropanol. In the second method, DNA was extracted by treatment of the cells with guanidine hydrochloride (GHCl) and precipitated with ethanol. Thirty strains of representative gram positive and gram negative species were included in the study. Preparations derived from confluent growth on one-quarter of the surface of agar plates and from 10(8) cells were subjected to each extraction procedure and analyzed for their content of DNA, RNA and protein. The suitabilities of the resultant DNA for restriction enzyme digestion and biotin-labelling by a random primer technique were also assessed. In general, the CTAB method yielded greater amounts of DNA than the GHCl procedure. RNA was present in most preparations of both types, but in amounts detectable only by agarose gel electrophoresis. The latter technique also revealed that DNA was not excessively sheared by either procedure. Protein was detected in some CTAB and GHCl preparations, but was not consistently associated with one or the other method. DNA obtained by both methods could be digested by the restriction enzyme EcoR I. In addition, biotin-labelled DNA probes prepared from CTAB and GHCl preparations were capable of hybridizing with homologous target DNA fixed to nitrocellulose. Since the CTAB method was consistently successful in recovering DNA from preparations containing 10(8) cells, it may be more suitable for the direct treatment of single colonies taken from primary isolation plates or plaque samples.

Bacteria↗
PubMed1989

"Reverse" DNA hybridization method for the rapid identification of subgingival microorganisms.

A "reverse" hybridization method is described, in which whole chromosomal DNA was extracted from 10-20 colonies of "unknown" strains in pure culture and labelled with digoxigenin by a random primer technique. DNA probes were prepared from a total of 23 strains and hybridized with targets containing 100 ng purified, denatured DNA from 38 reference strains fixed to nitrocellulose. 21/23 digoxigenin-labelled DNA probes successfully detected all members of the homologous species present on filters. Probes to Fusobacterium nucleatum strains 364 and MG detected 3/4 and 1/4 members of this species, respectively; 13/23 probes were 100% specific, but cross reactions between 10 probes and DNA targets from closely related, heterologous species occurred in 15/834 possible instances. False-positive reactions that occurred between closely related species were, however, easily distinguished and did not prevent the accurate identification of probe strains. Digoxigenin-labelled probes were capable of detecting 100 pg of homologous DNA. The reverse hybridization procedure allows identification or grouping of a large number of isolates within 3 days and provides a more economical means of characterizing subgingival isolates than predominant cultivable techniques and conventional phenotypic testing. This method could be adapted for the direct identification of microorganisms in subgingival plaque samples.

Bacteria↗
PubMed1989

The predominant cultivable microbiota of crevicular epithelial cells.

The purpose of the present investigation was to compare the composition of the predominant cultivable microbiota associated with gingival crevicular epithelial cells with that of the unattached microbiota recovered from the same site. Samples were taken from 2 diseased sites from 8 periodontal patients, by scraping the epithelial lining of the pocket with a curette. The epithelial cells were separated from the unattached subgingival bacteria by centrifugation in a reduced 50% Percoll density gradient. Epithelial cells formed a band at the top of the gradient and were removed separately from the unattached bacteria located at the base. Each layer was dispersed, diluted and plated on Trypticase soy agar with 5% sheep blood and 50 isolates were characterized from each sample. The microorganisms associated with the epithelial layer harbored 5- to 20-fold higher mean percentages of Bacteroides gingivalis, Bacteroides intermedius and Peptostreptococcus micros. The layer of unattached organisms exhibited 4- to 10-fold higher mean percentages of Streptococcus uberis, Capnocytophaga ochracea, Eikenella corrodens and Veillonella parvula.

Colony Count, Microbial↗
PubMed1989

Non-isotopic DNA probes for the identification of subgingival microorganisms.

The purpose of the present investigation was to examine the potential of non-isotopic DNA probes to identify pure cultures in predominant cultivable microbiota studies. Non-isotopic DNA probes to 7 subgingival species were prepared by 2 methods. In the first, biotin-labelled probes were prepared by nick translation. In the second, single-stranded DNA was covalently linked to horseradish peroxidase via polyethyleneimine. The relative sensitivities and specificities of these probes were tested against pure cultures of a range of subgingival species. Aliquots of broth cultures were standardized by optical densities, placed on nitrocellulose or Whatman 541 filters and then treated to lyse the cells, denature and fix DNA to the filter. Using a streptavidin-alkaline phosphatase detection system, 10(4)-10(5) cells were detected by homologous biotin-labelled probes. Horseradish peroxidase-labelled probes were approximately one order of magnitude less sensitive. Non-specific reactions with unrelated species, displayed by both biotin- and horseradish peroxidase-labelled probes, were eliminated by treatment of filters with proteinase K and organic solvents. Cross-reactions between closely related species could be discriminated by comparing reaction intensities of the test strains with probes to the each of the cross-reacting species involved. Thus, nonisotopic DNA probes could be used for the rapid identification of subgingival isolates. The technique could also be used for the recognition and grouping of strains of unknown species. A probe made to the strain of an unknown species may be used to rapidly screen hundred of unknown isolates for related strains.

Biotin↗
PubMed1989

Rapid method for the purification of DNA from subgingival microorganisms.

A method is described which facilitates the rapid purification of high molecular weight chromosomal DNA from gram positive and gram negative bacteria grown on solid media. A total of 32 reference strains and fresh isolates were examined in this study. The purification procedure involved lysis of cells with SDS in the presence of proteinase K, followed by removal of cellular polysaccharides and proteins with hexadecyltrimethyl ammonium bromide (CTAB) and phenol:chloroform:isoamyl alcohol. Preparations were incubated with RNase and, after removal of the enzyme, DNA was precipitated with ethanol. Several hundred micrograms of DNA could be prepared within 5 h from cells grown on 1-2 agar plates. None of the final preparations contained RNA; protein was detected in 12/32 preparations. The resultant DNA proved suitable for restriction enzyme digestion and biotin-labelling by a random primer technique. DNA probes constructed from these preparations were capable of detecting 100 pg of homologous target DNA fixed to nitrocellulose. Cross reactions between closely related species displayed weaker signal intensities than, and, thus, were easily distinguished from, true positive reactions between homologous species. DNA obtained by this procedure may also be suitable for DNA-DNA homology studies, recombinant DNA experiments and molecular fingerprinting.

Bacteria↗
PubMed1989

Longitudinal changes in periodontal disease in untreated subjects.

About 300 subjects, 20-79 years of age were recruited for a longitudinal study on the effect of periodontal therapy. The result of a baseline examination have been reported earlier. Following this baseline examination, the subjects were monitored for 24 months without therapy. Re-examinations were performed after 12 and 24 months. All teeth including the 3rd molars were included in the examinations. Presence of plaque was assessed at 4 surfaces per tooth and gingivitis, probing pocket depth, probing attachment levels were assessed at 6 locations per tooth. Out of the subject sample examined at baseline, 57 individuals failed to return for either the 1st, the 2nd or both re-examinations. An analysis was performed regarding the periodontal status at baseline, of the respondents and non-respondents. The results from the follow-up examinations of the participating 20 to 79 year-old subjects revealed that the sample underwent, during a 2-year period, only minor changes with respect to a series of different parameters characteristic of periodontal disease. Thus, the mean values of probing pocket depth and probing attachment level failed to change between baseline and the re-examinations after 1 and 2 years. Even if the mean values underwent only minor changes, however, certain subjects within each age category improved their periodontal conditions, whereas other subjects worsened. Furthermore, the findings of the re-examinations revealed that there was a strong correlation between improving plaque levels and gingivitis. The relationship between supragingival plaque levels and changes with respect to probing depth and attachment levels were weak.

Adult↗
PubMed1989

Periodontal loser sites in untreated adult subjects.

Subjects in age groups between 20 and 79 years were recruited for a study on the effect of different modalities of periodontal therapy. A baseline examination included assessments of plaque, gingivitis, probing pocket depth and probing attachment level. The subjects received no periodontal therapy for 2 years but were recalled for re-examination after 1 and 2 years. The results from the baseline examination and the overall changes which occurred in the sample during the 2 years have been reported previously. The present study describes some characteristics of subjects and sites that lost probing attachment of 3 mm or more during the course of the 24 months of monitoring. 161 of the 265 subjects who returned for both re-examinations had no change of the attachment level at any site that amounted to 3 mm or more. Of the 104 subjects that showed deterioration, at or above this level, the majority exhibited disease activity either during the 1st or the 2nd year of monitoring. Only 20 subjects showed disease activity during both year 1 and year 2. In addition, 70% of the sites that deteriorated (loser sites) occurred in 12% of the subjects. Loser sites were most frequently detected in older subjects and at molar sites. Most of the loser sites occurred at interproximal surfaces and were most numerous at surfaces with initially advanced loss of attachment.

Adult↗
PubMed1989

Relationship of clinical parameters to attachment loss in subsets of subjects with destructive periodontal diseases.

23 subjects were followed prior to treatment for 5 to 12 months in an attempt to relate attachment loss during this period to attachment level, probing depth, gingival redness and bleeding on probing. The subjects were divided into 3 groups based on amount and distribution of prior attachment loss: minor periodontitis, predominantly molar periodontitis and generalized periodontitis. The % of sites that exhibited attachment loss during the study period in the minor periodontitis, predominantly molar periodontitis and generalized periodontitis groups, were 1.3, 8.1 and 5.4, respectively. Subjects with minor periodontitis and predominantly molar periodontitis exhibited attachment loss more frequently in molar sites, proximal sites and sites with attachment level greater than or equal to 4 mm. In subjects with generalized periodontitis, attachment loss was related to tooth surface and attachment level, but not to tooth type. The relationship between the clinical parameters and attachment loss was improved compared with previous studies by using more homogeneous subject groups, more sensitive methods of analyzing attachment change and multivariate data analysis. However, the clinical parameters could not be used as diagnostic tests to predict attachment loss at individual sites.

Adult↗
PubMed1988

Clinical, microbiological and immunological features of subjects with refractory periodontal diseases.

27 subjects with active destructive periodontal diseases were treated by modified Widman flap surgery and systemic tetracycline and divided into 4 groups based on pre- and post-therapy hazard rates (% of sites losing greater than 3 mm of attachment in 1 year). Pre- and post-therapy hazard rates were respectively: group I (3 subjects) less than 4 and less than 4; group II (8 subjects) greater than 4 and less than 4; group III (3 subjects) less than 4 and greater than 4; group IV (refractory group of 13 subjects) greater than 4 and greater than 4. Baseline mean pocket depths and attachment loss of groups I and II subjects were less than groups III and IV subjects and exhibited less suppuration. 6 group IV subjects lost a total of 38 teeth after therapy, in contrast to no tooth loss in subjects in the other 3 groups. Redness, bleeding on probing, plaque levels and age did not differ among groups. Subjects in the 4 groups differed in the subgingival species to which they showed elevated serum antibody responses. Group IV subjects showed elevated responses to a select range of gram-negative species, including A. actinomycetemcomitans strains Y4 or ATCC 29523, F. nucleatum and B. intermedius. No subject in any of the other groups exhibited an elevated response to B. intermedius. The mean % of each species in all sampled sites, both before and after therapy, was computed for each subject. Subjects in groups III and IV (high post-therapy hazard rates) exhibited elevated mean levels of B. forsythus, F. nucleatum, S. intermedius, E. corrodens, and B. gingivalis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Clinical, microbiological and immunological features of subjects with destructive periodontal diseases.

76 subjects with prior evidence of destructive periodontal diseases were monitored clinically and immunologically every 2 months for up to 5 years. Clinical parameters measured included bleeding on probing, gingival redness, plaque accumulation, suppuration, pocket depth and attachment level. Blood samples were taken by venipuncture and serum antibody levels to a series of 18 subgingival species determined. 33 of these subjects showed evidence of active disease during the monitoring period, based on changes in attachment level measurements assessed using the tolerance method of analysis. Mean attachment loss in these 33 subjects varied from 1.4 mm to 9.0 (median value 3.4 mm) and subjects whose mean attachment level was above the median showed a higher % of pockets greater than 3 mm and more suppuration. Severity of gingival inflammation related poorly to mean attachment loss. Subgingival plaque samples were taken from the active site(s) and from control sites of equal pocket depth and attachment loss in the same active disease subjects, prior to therapy, for predominant cultivable microbiota studies. 50 randomly selected isolates were identified from each sample. Predominant cultivable species in 170 pretreatment active and inactive sites combined (8500 isolates) were enumerated. The most frequently detected species were F. nucleatum (112 sites) and S. intermedius (106 sites), although the predominant species in the samples from each subject differed. The distribution of putative pathogens differed among subjects. For example, A. actinomycetemcomitans was found in 21 samples in 11 subjects and B. forsythus was found in 18 samples from 10 individuals. Antibody response patterns to the 18 subgingival species also varied among subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Effect of modified Widman flap surgery and systemic tetracycline on the subgingival microbiota of periodontal lesions.

33 subjects with evidence of active destructive periodontal disease were treated by modified Widman flap surgery and systemic tetracycline (1 g/day for 21 days). Subgingival plaque samples were taken from 41 sites in 12 of these subjects before and 6 months after therapy for predominant cultivable microbiota studies. Mean pocket depth and attachment levels in the 41 sampled sites were 7.1 +/- 2.9 mm and 7.7 +/- 3.2 mm prior to therapy and 4.8 +/- 2.3 mm and 6.2 +/- 3.4 mm after therapy. B. melaninogenicus and V. parvula were more frequently detected in samples taken after therapy, while S. intermedius, S. morbillorum, S. uberis and W. recta were less frequently detected after therapy. A. actinomycetemcomitans were detected in 7 sites pretherapy and 1 site post therapy. The frequency of detection of B. gingivalis and B. intermedius was virtually unchanged. The mean levels of the Actinomyces sp., A. actinomycetemcomitans, B. gingivalis, B. intermedius, S. morbillorum, S. uberis and W. recta were decreased after therapy, while the mean levels of B. melaninogenicus, S. mitis, S. sanguis II and V. parvula were increased after therapy. V. parvula showed the greatest increase to 8.2% of the microbiota. In the second phase of the study, subgingival plaque samples from 94 sites in the 33 treated subjects were analyzed by predominant cultivable techniques. As a result of therapy, 24 sites exhibited attachment loss greater than 2 mm, 23 sites exhibited "gain" greater than 2 mm and the remaining 47 sites were considered to be unchanging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

The predominant cultivable microbiota of active and inactive lesions of destructive periodontal diseases.

Subgingival plaque samples were taken from active and inactive lesions in 33 subjects exhibiting active destructive periodontal diseases. Active diseased sites were those which showed a significant loss of attachment within a 2-month interval as computed by the "tolerance method". The predominant cultivable species from 100 active sites were compared with those found in 150 inactive sites of comparable pocket depth and attachment level loss. Among the 33 subjects, W. recta, B. intermedius, F. nucleatum, B. gingivalis and B. forsythus were elevated more often in active sites; whereas, S. mitis, C. ochracea, S. sanguis II, V. parvula and an unnamed Actinomyces sp. were elevated in inactive sites. The likelihood of a site being active was increased if B. forsythus, B. gingivalis, P. micros, A. actinomycetemcomitans, W. recta, or B. intermedius were detected in that site, and decreased if S. sanguis II, the Actinomyces sp., or C. ochracea were detected.

Actinomyces↗
PubMed1988

Relationship of subgingival microbial complexes to clinical features at the sampled sites.

Subgingival plaque samples from 100 active destructive periodontal lesions and 150 inactive subgingival sites in 33 subjects were analyzed by predominant cultivable microbiota techniques. 50 isolates were characterized from each sample and where possible, the isolate was placed in 1 of 134 microbial species or groups. The sites were clustered on the basis of the proportions of all of the species detected in each sample using a minimum similarity matching coefficient and an average unweighted linkage sort. 10 clusters containing 166 sites were formed which exhibited greater than 35% minimum similarities. All clusters were made up of sites from multiple subjects and were formed on the basis of different combinations of micro-organisms. Certain complexes of micro-organisms appeared to relate to the severity of periodontal destruction and the activity of the sampled site. The combination of F. nucleatum, B. forsyth and W. recta (cluster VII) or B. gingivalis, B. intermedius and S. intermedius (cluster VIII) distinguished clusters made up of sites which on average had the most attachment loss and the deepest pockets. These clusters contained the highest proportions of active sites and sites which lost greater than 3 mm of attachment after therapy. Clusters dominated by V. parvula (cluster III), the Actinomyces sp. (cluster X) or the combination of S. sanguis II, S. mitis, V. parvula and S. intermedius (cluster II) were made up of sites which exhibited less active disease and responded more favorably to therapy. Sites in other clusters exhibited moderate levels of prior destructive disease and disease activity status closer to the mean values for all 250 sites.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Probing depth, attachment loss and gingival recession. Findings from a clinical examination in Ushiku, Japan.

The present investigation describes probing pocket depth, probing attachment level and recession data from 319 randomly selected subjects, aged 20-79 years, from Ushiku, Japan. The findings are reported as mean values, frequency distributions and percentile plots of the 3 parameters at buccal, interproximal and lingual surfaces of single rooted (incisors, canines, premolars) and molar teeth. Inter-as well as intra-examiner errors for probing pocket depth and probing attachment levels were assessed and found to be small. The data reported revealed that practically all subjects studied had one or more sites in the dentition affected by destructive periodontal disease and that the severity of disease increased with age. It was further observed that in each age group, molars had suffered more attachment loss than single rooted teeth and that the interproximal surfaces as a rule had lost more periodontal tissue support than corresponding buccal and lingual surfaces. The attachment loss difference observed between different surfaces of a given tooth or a group of teeth, however, was comparatively small. In the age groups between 20-59 years, advanced destructive periodontal disease was found in a small subgroup of the subject sample, while after the age of 60 years, widespread destructive periodontitis was common. An attempt was made to examine the progression of destructive disease with age by comparing the frequency distributions of sites with attachment loss of greater than or equal to 3 mm in subjects of different age groups. The data suggested that in younger subject groups, progression was confined to a subset of individuals, while in older age groups, more subjects and sites became involved. A major feature of destructive periodontal disease in older individuals was the accompaniment of attachment loss with recession at the gingival margin. Deep pockets were relatively infrequently detected, while advanced loss of attachment (with recession) occurred at many sites.

Adult↗