bluuebunny/crossref_metadata_2025 huggingface dataset:
Further studies on the degradation of immunoglobulins by black‐pigmented Bacteroides
Authors: Grenier Daniel , Mayrand Denis , McBride Barry C.
Published: December 2007

The ability of several species of black‐pigmented Bacteroides to degrade immunoglobulins A and G was confirmed in this study. The cleavage products from IgG strongly stimulated the growth of bacteria degrading IgG. Growth of Bacteroides gingivalis on limiting media supplemented with IgG paralleled growth on complete medium. The degradation of IgG and IgA by black‐pigmented Bacteroides appeared to occur in 2 stages. The molecules were broken into large fragments which were subsequently degraded into small peptides not visible on SDS‐PAGE. B. gingivalis degraded IgG to peptides with Mrs of 33,000 and 11,000 whereas Bacteroides asaccharolyticus, Bacteroides intermedius and Bacteroides loescheii formed only the 33,000 Mr peptide. Electrophoresis in polyacrylamide gels containing covalently linked IgG, IgA and bovine serum albumin revealed that B. gingivalis elaborated 8 electrophoretically distinct proteolytic activities. The proteases protected the cell from reaction with anti‐B. gingivalis antibody and were capable of hydrolyzing antibody bound to the bacterial cell surface.
Identification procedures for oral Actinomyces species
Authors: Kalfas Sotirios , Edwardsson Stig
Published: December 2007

Rapid tests for carbohydrate fermentation, nitrate reduction and enzymic reactions with single reagents were used for species identification of 144 isolates being gram‐positive pleomorphic rods and belonging to the genus Actinomyces. The isolates derived from human supragingival and subgingival plaque. The results were compared with those obtained with reference strains as well as other previously identified strains belonging to Actinomyces and to the related genera Arachnia, Bifidobacterium, Propionibacterium and Rothia. The results showed that species identification within the genus Actinomyces was possible with the tests studied. A key for identification work is hereby provided.
The role of pH in salivary histidine‐rich polypeptide antifungal germ tube inhibitory activity
Authors: Brant E. C. , Santarpia R. P. , Pollock J. J.
Published: December 2007

Purified synthetic salivary histidine‐rich polypeptides (HRPs) 2, 3, 4, 5 and 6 were found to inhibit Candida albicans conversion of blastospores to germ tubes. HRP‐4 was the best inhibitor within the pH 5 to 7 range tested and all of the HRPs were observed to lose potency as the pH was raised from 5 to 7. The pH pattern obtained with a synthetic homologous histidine peptide suggested that the protonated form of the histidine imidazole residues of the HRPs was important to the germ tube antifungal activity. Similar pH inhibition profiles of germ tube formation by parotid saliva and the HRPs were also observed.
Function of anti‐Strepfococcus mutans antibodies: inhibition of virulence factors and enzyme neutralization
Authors: Gregory Richard L. , Kindle Janice C. , Hobbs Laura C. , Filler Steven J. , Malmstrom Hans S.
Published: December 2007

The levels of parotid salivary IgA and serum IgG antibodies from dental caries‐resistant (CR) and caries‐susceptible (CS) individuals to Streptococcus mutans antigens were determined. In general, the levels of salivary IgA and serum IgG antibodies to S. mutans antigens were significantly higher in CR subjects than in CS individuals. There were significantly higher levels of IgA2, but not IgAl, salivary antibodies to S. mutans whole cells in CR subjects than in CS individuals. These results led us to investigate the functional effects parotid saliva and sera containing these antibodies had on several factors associated with S. mutans virulence. Parotid saliva and sera from CR subjects significantly inhibited S. mutans growth, adherence, acid production, glucosyltransferase and glucose‐phospho‐transferase activities to a greater extent than saliva and sera from CS individuals. The data suggest that neutralization of S. mutans enzymes and inhibition of S. wutans virulence factors by saliva and serum may be responsible for the lower numbers of carious lesions in CR subjects.
Interaction of structural isomers of sucrose in the reaction between sucrose and glucosyltransferases from mutans streptococci
Authors: Minami Takahiro , Fujiwara Taku , Ooshima Takashi , Nakajima Yoshikazu , Hamada Shigeyuki
Published: December 2007

Structural isomers of sucrose, i.e. disaccharides composed of glucose and fructose molecules with different glucosidic linkages, were examined for their effect on the reaction between sucrose and various glucosyltransferases (GTases) from Streptococcus mutans MT8148 and Streptococcus sobrinus 6715. Trehalulose (al‐l), turanose (a1‐3), maltulose (a 1–4), and palatinose (a 1–6) were used as the sucrose analogues. Mutans streptococci were found not to utilize these sucrose analogues. Analysis of enzymatic products of GTase and sucrose with thin layer enrornatography clearly revealed that glucan synthesis from [14C]sucrose by the various purified GTase preparations from S. mutans and S. sobrinus was significantly inhibited in the presence of these sucrose analogues except turanose, resulting in the release of increased amounts of [14C]fructose and [14C]oligosaccha‐rides. It was also found that the fructose residues in the oligosaccharides were de‐rived from those of sucrose analogues but not sucrose itself. The Lineweaver‐Burk Plots of the substrate saturation kinetics of GTase vs sucrose indicated increased Km and Vmax in the presence of sucrose analogue, as compared with sucrose alone. Finally, these sucrose analogues except turanose inhibited sucrose dependent cellular adherence of S. sobrinus 6715 to a glass surface, while they scarcely inhibited the adherence of s. mutans MT8148. Among the analogues, maltulose appeared the most effective inhibitor against GTases in general.
Characterization and physical mapping of plasmids of black‐pigmented Bacteroides
Authors: Yoshimoto Hisashi , Umemoto Toshio
Published: December 2007

Eight species of black‐pigmented Bacteroides (BPB) were examined for plasmid content. Three classes of plasmids with molecular sizes of 16.0 kilobase (kb), 5.4 kb and 5.0 kb were found in 7 of 125 Bacteroides intermedius strains. One strain each of Porphyromonas (former Bacteroides) asaccharolyticus and of Bacteroides levii were also shown to have plasmids. However, no plasmids were detected in 90 strains of Porphyromonas (Bacteroides) gingivalis. The plasmids were purified and digested with restriction endonucleases for restriction mapping. The maps obtained in this study have given us information on the scheme of constructing recombinants which may be usable as shuttle vectors, by the recombination of BPB and Escherichia coli plasmids.
Structural proteins of the Actinobacillus actinomycetemcomitans bacteriophage øAa
Authors: Stevens R. H. , Hammond B. F. , Fine D. H.
Published: December 2007

Aa is an A 1 morphotype bacteriophage which infects certain strains of Actino bacillus actinomycetemcomitans. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) analysis of dissociated, purified ØAa particles revealed 7 major structural proteins (P1‐P7) ranging in size from 17.5 to 52.7 kilodaltons (Kd). Treatment of the intact phage particles with 67% dimethyl sulfoxide (DMSO) resulted in the separation of the virion head and tail subunits. Purification of the head subunits was accomplished by sucrose density gradient centrifugation of the DMSO‐treated phage particles. The purified head subunits were composed of a single protein having an electrophoretic mobility which corresponded to a 39.5 Kd protein (P3) of the intact virus. Raising the pH of a purified 0Aa suspension to 12.7 disrupted the head subunits, as well as the tail tube and tail fibers, releasing intact contractile tail sheaths. The tail sheaths were collected by centrifugation. The purified tail sheaths were analyzed by SDS‐PAGE and were found to be composed of two proteins (PI and P2) having molecular weights of 52.7 and 41.2 Kd respectively. The location of each of the 4 remaining major structural proteins in the øAa virion remains to be determined.
Metabolism of progesterone and testosterone by Bacillus cereus strain Socransky 67 and Streptococcus mutans strain Ingbritt
Authors: Ojanotko‐Harri Anita , Nikkari Tarja , Harrl Matti‐Pekka , Paunio Keijo
Published: December 2007

Bacillus cereus strain Socransky 67 and Streptococcus mutans strain Ingbritt grown overnight in complex medium and then in fresh medium flasks for 5h‐ The bacterial cells in the medium were centrifuged and resuspended; 4‐14C‐Progesterone or 4–14C ‐testosterone was added, and the samples were incubated for 2 h at 37 °C in a shaking water bath. The metabolites were analyzed with column and thin layer chromatography and radioautography and quantified by liquid scintillation counting. On the basis of the metabolites found it was and concluded that B. cereus strain Socransky 67 contains 5a‐steroid hydrogenase. and 3β‐, 17β and 20a‐hydroxysteroid dehydrogenases and probably also steroid hydroxylases, and that S. mutans strain Ingbritt contains 5a‐ and 5β–steroid Wrogenases, and 3a–, 17β– and 20a–hydroxysteroid dehydrogenases. The metabolic activity of B. cereus is several times higher than that of S. mutans. We Suggest that the greater ability of B. cereus to metabolize progesterone and testosterle is probably due to its growth milieu in the gingival sulcus, where it is nearer 1 the gingival tissue.
Chronic peroral administration of Streptococcus sobrinus to conventional laboratory rats produces cycling levels of salivary antibodies
Authors: Riviere George R. , Bohaty Brenda S. , Pratt Sherelene Y. , Wagoner Murriel A.
Published: December 2007

Conventional outbred rats were fed Streptococcus sobrinus for 24 weeks and ELISA was used to identify isotypes of antibodies against bacteria in saliva and serum. Quantities of antibodies from experimental rats were compared with values derived from the control population. Saliva IgM and IgA anti‐S. sobrinus from experimental rats were greater than controls at week 3, were much less at week 9, but normal levels were found by week 13. IgG antibodies in saliva peaked at weeks 5 and 9 but fell to control levels by week 13. Relative levels of antibodies in saliva of experimental animals continued to cycle during weeks 13–24 but did not differ greatly from controls. Serum IgM and IgG antibodies to S. sobrinus were essentially like controls throughout the experiment. Serum IgA increased briefly during the first 12 weeks then returned to normal levels. The results suggest that prolonged peroral exposure to cariogenic bacteria ultimately leads to modulation of antibody around unimmunized control levels even though antigenic stimulation persists.
Factors affecting peptide catabolism by oral streptococci
Authors: Rogers A. H. , Pfennig A. L. , Gully N. J. , Zilm P. S.
Published: December 2007

The binding of a number of unsubstituted peptides to Streptococcus sanguis and Streptococcus mutans and their subsequent degradation by such cells were examined. Peptides were added to cell suspensions prepared from glucose‐limited growth in a chemostat and, at appropriate time intervals, cell‐free filtrates were analyzed for peptides and their constituent amino acid residues by high‐pressure liquid chromatography techniques. The results indicated that peptide hydrophobicity plays a limited role in peptide binding, but that charge and chain‐length are probably important. In S. sanguis, carboxypeptidase activity rapidly released C‐terminal arginine (Arg); this amino acid was less rapidly released from the N‐terminus but a number of other residues were also released by aminopeptidase activity. When Arg is buried in the peptide, the rate of its release depends upon the number and type of residues between it and the N‐terminus. In contrast, S. mutans possessed only weak peptidase activities. The nature of its peptidase activities indicates that S. sanguis can obtain the metabolically important Arg from a variety of peptides.
Rapid antimicrobial resistance screening method for Bacteroides intermedius
Authors: Calsina G. , Lee Y.‐S. , Newmani M. G. , Kornman K. S. , Nachnani S. , Flemmig T. F.
Published: December 2007

The purpose of the study was to validate a rapid resistance screening (RRS) method for antimicrobial susceptibility testing of a selected periodontopathic microorganism using the standard broth dilution method as a control. Twenty‐five subgingival plaque samples from gingivitis or periodontitis sites were plated °n Trypticase soy agar supplemented with 5% rabbit blood with antibiotic discs (RRS method) and without (control). The antibiotics tested were: Augmentin®, clindamycin, erythromycin, metronidazole, penicillin G and tetracycline hydro‐chloride. Bacteroides intermedius isolated from both groups of plates were placed onto antibiotic supplemented Trypticase soy broth. The antibiotic susceptibilities of B. intermedius isolated from the plates with antibiotic discs and the standard broth method were compared. The results showed high sensitivity and predictability for the RRS method compared with the control. The percentage of agreement was: 100% for Augmentin® 30 μg, clindamycin 2 fig and tetracycline 30 μg; 96% for erythromycin 15 fig, metronidazole 80 fig and penicillin 10 IU; 92% for Penicillin 2 IU; 88% for erythromycin 2 fig and 84% for tetracycline 5 fig. The results of this study document the feasibility of the RRS method for testing antimicrobial resistance of whole samples if its efficacy can be demonstrated for other bacteria. This method may be a quick and useful test for the periodontal Practitioner in determining the antibiotic susceptibility of periodontal plaque Pathogens.
Are certain oral pathogens part of normal oral flora in denture‐wearing edentulous subjects?
Authors: Könöonen Eija , Asikainen Sirkka , Alaluusua Satu , Kononen Mauno , Summanen Paula , Kanervo Arja , Jousimies‐Somer Hannele
Published: December 2007

A complete loss of teeth may eliminate some pathogenic bacteria for lack of a suitable habitat for colonization. The occurrence of Actinobacillus actinomycetemcomitans, black‐pigmented Bacteroides, mutans streptococci, lactobacilli and yeasts was investigated in 51 edentulous subjects with complete denture(s); mean age 74 years (range 44–92 years). None of the subjects had received antibiotics during the preceding 6 months. Four swab samples per subject were taken from the fitting surface of the upper denture, from the palate, buccal mucosae and dorsum of the tongue. At least 0.5 ml of stimulated saliva was collected into a sterile tube. The samples were cultivated aerobically and anaerobically using non‐selective and selective media. A. actinomycetemcomitans was not found in any of the samples. Black‐pigmented Bacteroides were found in 49 (96%) and yeasts in 25 (49%) of the subjects. Of the 49 saliva samples, 41 (84%) yielded mutans streptococci and 45 (92%) lactobacilli. In contrast to black‐pigmented Bacteroides, mutans streptococci and lactobacilli, A. actinomycetemcomitans may not belong to the normal oral flora of edentulous subjects wearing dentures.
Selective effects of histidine‐rich polypeptides on the aggregation and viability of Streptococcus mutans and Streptococcus sanguis
Authors: Payne Jeffrey B. , Iacono Vincent J. , Crawford Isabelle T. , Lepre Biagio M. , Bernzweig Eric , Grossbard Barbara L.
Published: December 2007

Enriched preparations of histidine‐rich polypeptides (HRPs) and isolated HRP pairs (1–2, 3–4 and 5–6) degrade in the presence of fresh autologous whole saliva to a series of low‐molecular‐weight cationic peptides (HRPs 6a–c and 7). Analysis of the HRPs during degradation indicates that: HRP 1 is not the parent molecule of the HRPs; the HRP pairs do not convert to each other in a cascade‐like sequence in saliva; and the HRPs can be separated into 2 groups consisting of HRps 1–2 and 3–7. Preparations containing HRPs 1–7, 1–2, and 3–7 were obtained by fractionation and separation on Bio‐Rex 70, and tested for aggregating and antibacterial effects against Streptococcus mutans BHT, S. mutans GS‐5 and Streptococcus sanguis G9B. HRPs 1–2 had significant aggregating effects on all 3 strains but the other HRPs had little to no agglutinating ability. The HRPs did not inhibit the growth of S. sanguis, and HRPs 1–2 enhanced its growth. No growth enhancement by the HRPs was observed for the 2 S. mutans strains. However, significant bacterial inhibition of the S. mutans strains was noted after incubation with HRPs 3–7. The data suggest that the dissimilar effects of HRPs 1–2 and 3–7 may be of importance in the colonization and growth of S. mutants and S. sanguis in vivo.
Immunodominant antigens of Actinobacillus actinomycetemcomitans serotypes a and c in high‐responder patients
Authors: Califano Joseph V. , Schenkein Harvey A. , Tew John G.
Published: December 2007

This study was undertaken to examine the characteristics of the immunodominant antigens of Actinobacillus actinomycetemcomitans serotypes a and c. The top responders for A. actinomycetemcomitans serotypes a and c were selected (19 for serotype a and 21 for serotype c) from 150 clinically characterized patients. Competition assays revealed that 9 of 19 of these patients were reacting specifically to serotype a and 12 of 21 for serotype c. Limiting dilution analysis on Western blots revealed that most antigen bands apparent at low dilution disappeared as the patient's serum was diluted. The antigen band(s) remaining at the endpoint or the dilution corresponding to the antibody liter were defined as immunodominant. For serotype a there were several different Immunodominant antigens but none was present in more than half of the subjects. For serotype c the immunodominant antigens included a number of discrete bands and a diffuse smeared polysaccharide band. Only 2 of these antigens were present in the majority of the high‐responders: 92% had the smeared antigen and 67% had a 15 kDa antigen. The 15 kDa band was a protein common to all A. actinomycetemcomitans serotypes. The smeared antigen was unaffected by protease K treatment and gave a reaction of identity with the serotype c specific rabbit antiserum. This rabbit antiserum is specific for a mannan carbohydrate and does not react with LPS (23). Therefore, the smeared immunodominant antigen appears to be a polysaccharide containing mannan.
Electron immunocytochemical localization of Actinobacillus actinomycetemcomitans leukotoxin
Authors: Berthold P. , Forti D. , Kieba I. R. , Rosenbloom J. , Taichman N. S. , Lally E. T.
Published: December 2007

The Actinobacillus actinomycetemcomitans leukotoxin was localized in A. actinomycetemcomitans bacteria using an electron immunocytochemical thin‐section labeling method. An immuno‐dot blot procedure was initially used to ascertain the optimal specimen fixation. This consisted of a periodate‐lysine‐paraformaldehyde (2%) fixative in a phosphate buffer followed by embedding in LR White. Affinity‐purified toxin was used to produce a monospecific polyclonal antibody. The reaction sites were visualized with a colloidal gold‐tagged reporter antibody. The leukotoxin was found to be localized either in the cell envelope and/or in membranous vesicles on the outer surface of the bacterial cell. These results support previous observations indicating the same location.
One‐step purification of histidine‐rich polypeptides from human parotid saliva and determination of anti‐candidal activity
Authors: Lal K. , Santarpia R. P. , Xu L. , Manssuri F. , Pollock J. J.
Published: December 2007

Immunoadsorption affinity chromatography was used to selectively purify the family of the histidine‐rich polypeptides (HRPs) from human parotid saliva. The immunoadsorbent was prepared by coupling an enriched preparation of horse anti‐(HRPs 2, 3, 4, 5 and 6) IgG to protein G. Both freshly collected stimulated untreated and acidified boiled salivas (5 ml) were applied to the affinity column. When native saliva was used it appeared that all of the components of saliva, with the exception of the HRPs, were present in the fraction nonadsorbed to the affinity column; however, recovery of the HRPs with 0.2 M sodium acetate‐HCl, pH 1.8, was poor. Yields of HRPs desorbed from the column with the pH 1.8 treatment were significantly improved if salivary HRP proteolysis was delayed immediately after collection by acidifying the saliva to pH 4.5 followed by a short boiling time period, which neither affected HRP quantification nor biological activity. Affinity chromatography results were checked both by catronic polyacryl‐amide gel and by capillary electrophoresis. Antifungal activity was found to reside only in the low pH HRP fraction of the immunoadsorbent column, suggesting that it is the histidine‐rich family of polypeptides that is responsible for salivary antifungal action.
Direct and indirect effects of Porphyromonas gingivalis lipopolysaccharide on interleukin‐6 production by human gingival fibroblasts
Authors: Yamazaki K. , Ikarashi F. , Aoyagi T. , Takahashi K. , Nakajima T. , Hara K. , Seymour G. J.
Published: December 2007

We examined the production of interleukin‐6 (IL‐6) by human gingival fibroblasts (ATCC CRL 1292) stimulated with lipopolysaccharide (LPS) from Porphyromonas gingivalis and Escherichia coli, or supernatant of human peripheral blood adherent cell culture medium incubated in the presence of IL‐1 and the same two LPS. Confluent monolayers of gingival fibroblasts were incubated with stimulants for 6 h at 37°C in 5% CO2 and air. After removal of stimulants, the cell cultures were incubated for an additional 2 or 24 h in the same environment. At the end of the culture period, supernatants were collected and assayed for IL‐6 activity by stimulatory IgG production with the human B‐lymphoblastoid cell line CESS. The direct effect of LPS on IL‐6 production by gingival fibroblasts was much weaker than the indirect one via IL‐1 production by adherent cells. The stimulating effect of culture supernatants of adherent cells stimulated with LPS on IL‐6 production by gingival fibroblasts was as effective as that of recombinant IL‐1, when this latter was added at a concentration equivalent to that contained in the culture supernatant of adherent cells. These results suggest that, although gingival fibroblasts may be involved in the pathogenesis of chronic periodontal disease by the production of cytokines, such a role may not result from a direct stimulation by periodontopathic bacteria. The phenomenon is more likely to be mediated indirectly by IL‐1 produced by infiltrating inflammatory cells.
Strain identification of Actinobacillus actinomycetemcomitans using the polymerase chain reaction
Authors: Griffen A. L. , Leys E. J. , Fuerst P. A.
Published: December 2007

A molecular assay that distinguishes among strains of the periodontal pathogen Actinobacillus actinomycetemcomitans was developed by identifying DNA restriction site polymorphisms in the highly variable transcribed spacer region between the 16S and 23S ribosomal genes. The polymerase chain reaction (PCR) was used to amplify this region from genomic DNA using primers within conserved regions of the 16S and 23S genes. This amplified region was digested using a series of restriction enzymes and electrophoresed. Examination of restriction fragment length polymorphisms obtained by separate digestion with RsaI and NciI allowed the 7 strains examined to be divided into 4 genetic groups. This assay provides a more precise and reproducible method of strain identification than whole genomic methods and should be useful as a method for studying the epidemiology of A. actinomycetemcomitans strains in human subjects. The genetic variability detected supplies strong evidence that direct sequence analysis of the region could provide extremely precise and potentially definitive identification of strains.
Immunodominant antigens of Actinobacillus actinomycetemcomitans serotype b in early‐onset periodontitis patients
Authors: Califano J. V. , Schenkein H. A. , Tew J. G.
Published: December 2007

Previous work with Actinobacillus actinomycetemcomitans strain Y4 (serotype b) indicates that the immunodominant antigen in high‐responding patients (top 10%, 80% of which were black) is the serotype‐specific antigen. In this study we examined the immunodominant antigens of A. actinomycetemcomitans strain Y4 in both black and white patients having a range of antibody titers. We sought to test the hypothesis that the immunodominant antigen in these subjects was the same antigen found in high responders. Seropositive white early‐onset periodontitis (EOP) patients were selected from 99 EOP patients. Black subjects were then selected with comparable antibody titers. Double immunodiffusion and competition assays were used to determine whether reactive antibodies were A. actinomycetemcomitans serotype b‐specific or whether the response was to serotype a or c. The immunodominant antigens were then determined for the patients reacting specifically to A. actinomycetemcomitans Y4 using limiting dilution analysis on Western blots. The immunodominant antigen for the A. actinomycetemcomitans Y4‐specific patients appeared to be the serotype‐specific carbohydrate for most subjects (19/20 or 95%, including: 13/14 black and 6/6 white patients). In conclusion, the immunodominant antigen for A. actinomycetemcomitans Y4 was the serotype‐specific carbohydrate regardless of antibody titer for both black and while specifically reactive patients.
Isolation and properties of the Capnocytophaga ochracea bacteriocin
Authors: Nakamura T. , Shibata Y. , Shimura R. , Fujimura S.
Published: December 2007

A bacteriocin from a subgingival plaque isolate of Capnocytophaga ochracea was purified and characterized. It was isolated from cell extract and had a molecular weight of 100,000. Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans and Propionibacterium acnes were susceptible to the bacteriocin.
Serum IgG reactive with oral anaerobic microorganisms associated with infections of endodontic origin
Authors: Baumgartner J. C. , Falkler W. A. , Bernie R. S. , Suzuki J. B.
Published: December 2007

Numerous species of bacteria have been implicated with infections of endodontic origin. The purpose of this study was to compare the levels of serum IgG antibodies reactive with a panel of 10 oral anaerobic microorganisms implicated in infections of endodontic origin. Serum samples were collected from 4 patient groups that included healthy patients without endodontic or periodontal disease, patients with chronic adult periodontal disease, patients with endodontic disease and patients with combined endodontic‐periodontal disease. When Prevotella intermedia was allowed to react with sera from the 4 patient groups, significant pairwise differences were shown between the healthy group and each of the other 3 groups. In addition, there was a significant difference between the periodontal disease group and the combined endodontic‐periodontal disease group. When Porphyromonas gingivalis was allowed to react with sera from the 4 patient groups, significant pairwise differences were shown between the healthy group and the periodontal disease group, the healthy group and the combined endodontic‐periodontal disease group, the endodontic disease group and the periodontal disease group and the endodontic disease group and the combined endodontic‐periodontal disease group. The results of this investigation support other studies that associate P. intermedia with both endodontic disease and chronic adult periodontal disease. The results also support studies that implicate P. gingivalis as a periodontopathogen.
Effects of xylitol and fluoride on the response to glucose pulses of Streptococcus mutans T8 growing in continuous culture
Authors: Rogers A. H. , Bert A. G.
Published: December 2007

Streptocuccus mutans T8 was grown glucose‐limited at pH 7.0 in a chemostat and pulsed, under pH free‐fall conditions, with glucose, xylitol or a mixture of the two. Experiments were conducted in the absence or continual presence of low levels (1 mmol · 1−1) of fluoride. Culture filtrates of samples taken at frequent intervals were assayed for carbohydrate and fermentation end‐products. Fluoride had little effect on the organism's response to glucose until the culture pH fell to ca. 5.0, at which point the rate of lactate production was reduced some 3‐fold. Xylitol affected the response to glucose but its effect was most marked in the presence of fluoride. Under these conditions, the rate of lactate production was reduced at least 3‐fold, the pH did not fall to 5.0 and only about 50% of the added glucose was consumed. This suggests that xylitol can augment the metabolic effects on S. mutans of low levels of fluoride.
Relationship between oral gram‐negative anaerobic bacteria in saliva of the mother and the colonization of her edentulous infant
Authors: Könönen E. , Jousimies‐Somer H. , Asikainen S.
Published: December 2007

Various gram‐negative anaerobic bacterial species can be detected in the oral flora of edentulous infants. However, knowledge of the initial infection source is still scarce. Thirty Caucasian mothers (mean age 30 years) and their edentulous infants (mean age 3 months) were examined for the possible similarity of the oral gram‐negative anaerobic flora. Paraffin‐stimulated saliva was collected from the mothers. A pooled swab sample from mucosal surfaces and unstimulated saliva were collected from the infants. The samples were inoculated on nonselective and selective media and cultured aerobically and anaerobically. All of the 30 mothers harbored Fusobacterium nucleatum and 29 mothers Prevotella melaninogenica in their saliva. The salivary levels of P. melaninogenica, F. nucleatum, nonpigmented Prevotella spp., Prevotella intermedia and Prevotella loescheii exceeded 104 CPU/ml in about half of the 30 mothers. At this maternal salivary level, the infants' colonization frequency of P. melaninogenica and F. nucleatum was doubled. A positive correlation between maternal salivary concentration and infant's colonization was found for P. melaninogenica. No positive association was found with nonpigmented Prevotella spp., P. intermedia and P. loescheii. It can be speculated that maternal saliva may act as a source of some gram‐negative anaerobes in the oral micro flora of edentulous infants as early as before tooth eruption.
Immunoglobulin A antibody activity to mutans streptococci in parotid, submandibular and whole saliva
Authors: Widerström L. , Bratthall D. , Hamberg K.
Published: December 2007

Antigen extracts of 9 strains of Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius and Streptococcus mitis were separated in acrylamide gels by electrophoresis. Strains of the same genotype of mutans streptococci were found to have virtually identical sodium dodecyl sulfate‐polyacrylamide gel electrophoresis patterns but differed clearly from other genotypes of mutans or with the reference strains S. salivarius and S. mitis. Immunoglobulin A (IgA) antibody activity to antigens of S. mutans, S. sobrinus and S. mitis in the parotid, submandibular and whole saliva of 12 people was detected by Western blotting. IgA antibodies reacted with several of the antigens, and the reaction pattern was unique for each of the individuals. To certain antigens, all the salivas blotted bands if both clear and questionable bands were counted. Significantly more blotted bands were revealed with antigens from S. mutans than S. sobrinus. The results of the 3 different salivas of the same individual had a high degree of resemblance but in a few individuals, more blotted bands were obtained with parotid saliva to S. mutans and S. sobrinus antigens.
Expression of Porphyromonas gingivalis proteolytic activity in Escherichia coli
Authors: Madden T. E. , Thompson T. M. , Clark V. L.
Published: December 2007

Porphyromonas gingivalis (formerly Bacteroides gingivalis) degrades numerous protein substrates including collagen, fibrinogen, fibronectin, gelatin, casein, immunoglobulins and complement components. In order to clone one or more of these protease genes, a genomic library was constructed with Sau3Al restriction fragments of chromosomal DNA from P. gingivalis ATCC 33277 ligated into the temperature‐regulated vector pCQV2, and expressed in Escherichia coli DHSαmcr. The electro‐transformants (3 × 104) were screened for general protease activity on Luria broth agar containing ampicillin (50 mg/1) and sodium casein‐ate (2%). One casein‐hydrolyzing clone was detected and subcultured, and the activity of the cell extracts was characterized. We were able to show that the protease‐positive clone, (pTEMl), had broad substrate specificity. Colorimetric assays indicated the hydrolysis of azocoll, azocasein, collagen, elastin‐congo red and artificial substrates. Sodium dodecyl sulfate‐polyacrylamide gel electro‐phoresis was used to confirm that collagen, casein, fibrinogen and fibronectin were degraded by the clone.
Interaction of Porphyromonas gingivalis with gingival epithelial cells maintained in culture.
Authors: Lamont R. J. , Odo D. , Persson R.E. , Persson G.R.
Published: December 2007

Interactions between Porphyromonas gingivalis and gingival epithelial cells were investigated. Gingival epithelial cells were cultured from surgically removed gingival tissue. Electron microscopy demonstrated adherence of P. gingivalis to the cell membranes and microvilli followed by internalization of the bacteria into the epithelial cell cytoplasm. Saliva from healthy and periodontally diseased patients inhibited P. gingivalis association with the epithelial cells. Attachment to and penetration of gingival epithelial cells by P. gingivalis may be important virulence factors in periodontal disease. Salivary molecules may play a role in modulating these interactions.
Effects of fluoxetine on the oral environment of bulimics
Authors: Bretz W. A. , Krahn D. D. , Drury M. , Schork N. , Loesche W. J.
Published: December 2007

The purpose of this study was to evaluate in a double‐blind placebo‐based study the effects of fluoxetine over a period of 16 weeks on the frequency of hinging and purging and on fluctuations in the levels of cariogenic organisms and saliva secretion rate of patients (n= 30) with bulima nervosa. Profile analysis suggested that, over the course of the study, hinging and purging frequency and Streptococcus sobrinus salivary levels decreased significantly in the fluoxetine group as compared with the placebo group. Our finding that S. sobrinus levels decreased 16 weeks after subjects were on medication suggests that the salivary levels of these organisms could serve as an objectively measured indicator of patient compliance with antibulimic therapy.
Local and systemic antibody response to putative periodontopathogens in patients with chronic periodontitis: correlation with clinical indices
Authors: Kinane D. F. , Mooney J. , MacFarlane T. W. , McDonald M.
Published: December 2007

Specific immunoglobulin G (IgG), IgA and IgM antibody titres to Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans were measured by enzyme‐linked immunosorbent assay in serum and gingival crevicular fluid at 5 sites in each of 20 chronic periodontitis patients. Specific serum antibody litres correlated with mean gingival crevicular fluid litres. The 3 immunoglobulin subclass responses (IgA, IgG and IgM) to P. gingivalis correlated. A comparison of sites with probing depth < 4 mm and ≥4 mm showed that the latter group had significantly lower gingival crevicular fluid IgG titres lo P. gingivalis. Sites with a gingival index of 3 had significantly lower gingival crevicular fluid IgG litres to this organism than those with a gingival index of less than 3. These findings supporl the concepl that the humoral immune response is protective, as chronic periodontitis patients with greater pockel depths and more gingival inflammation had paradoxically lower antibody titres to suspected periodontopalhogens.
Characterization and physical mapping of the genome of bacteriophage ØAa from Actinobacillus actinomycetemcomitans
Authors: Stevens R. H. , Goncharoff P. , Furgang D. , Fine D. H. , Schreiner H. C. , Figurski D. H.
Published: December 2007

The size, configuration and restriction map of Actinobacillus actinomycetemcomitans bacteriophage ØAa DNA was determined by means of restriction endo nuclease analysis. Digestion of the ØAa DNA with restriction enzymes Hind III, Eco RI and Sal I produced 6, 5, and 4 fragments, respectively. Based upon the sum of the sizes of the restriction fragments of these enzymes, the DNA was estimated to be 47.2 kilobase pairs in length. A restriction map was constructed using Hind III and Sal I. Incubation with exonuclease Bal 31 for increasing lengths of time resulted in progressive hydrolysis of the DNA, as expected for a linear molecule. No sub molar fragments or diffuse bands were observed in the agarose gels of the restriction endonuclease digests of the ØAa DNA. Attempts at ligating the ends of the DNA were consistently unsuccessful. Therefore, we found no evidence for cohesive ends, a circular permutation of the genome or for headful packaging mechanism from a concatameric DNA precursor.
Effect of outer membrane of Treponema denticola on bone resorption
Authors: Gopalsami C. , Yotis W. , Corrigan K. , Schade S. , Keene J. , Simonson L.
Published: December 2007

The effect of the outer membrane (outer sheath) of Treponema denticola on bone resorption was studied. Bone resorption was measured by the release of previously incorporated 45Ca from the shafts of the radii and ulnae of 19‐day fetal rats. A treated‐over‐control ratio (T/C ratio) significantly greater than 1 indicated the stimulation of bone resorption by the test substance. The addition of outer membrane of T. denticola increased the release of 45Ca from the assay bones. The minimum concentrations required to yield significant 45Ca release from the assay bones were 15, 22 and 75 μg protein/ml for serovars a, b and c, respectively. These protein values corresponded to estimated lipopolysaccharide contents of 0.6, 0.8 and 2.8 μg/ml, based on 3‐deoxy‐2‐manno‐octulosonate analysis. Heat treatment of outer membrane (60° for 30 min) did not change the effect on 45Ca release. Parathyroid hormone or prostaglandin E2 known to act synergistically with lipopolysaccharides in bone resorption, was also added to the assay system. Neither prostaglandin E2 at 10‐7 M nor parathyroid hormone at 40 ng/ml, by itself, increased 45Ca release. However, in the presence of 10 μg protein/ml of outer membrane of serovar b at 120 h, the T/C ratio was increased to 1.31±0.07 and 1.58±0.118, respectively. These results suggest that a lipopolysaccharide‐like material is present in the outer membrane of T. denticola that may be responsible for bone resorption in the in vitro system.
Genetic transformation of Porphyromonas gingivalis by electroporation
Authors: Yoshimoto H. , Takahashi Y. , Hamada N. , Umemoto T.
Published: December 2007

Porphyromonas gingivalis was transformed by electroporation using the DNA of plasmid pE5‐2, or its derivative, pYT7. Prior to transformation, pE5‐2 was transferred from Escherichia coli to P. gingivalis strains by conjugation (mobilization with R751), and the plasmid DNA was purified from the P. gingivalis transconjugants. Transformation occurred when the recipient strain and the donor strain from which the plasmid DNA was purified were homologous. If they were heterologous, transformation did not take place or did so at a very low frequency. This suggested that a restriction‐modification system is present in P. gingivalis strains. Plasmid pYT7 was derived by removing an 8.0 kb AvaI fragment from pE5‐2 that was purified from P. gingivalis cells. It has several single‐cutting restriction sites such as EcoRI, AvaI and ClaI usable for gene cloning, though it was not stable enough in P. gingivalis cells, probably because the rep gene was derived from a relatively distant species, Bacteroides eggerthii.
Porphyromonas endodontalis: prevalence and distribution of restriction enzyme patterns in families
Authors: Petit M. D. A. , van Winkelhoff A. J. , van Steenbergen T. J. M. , de Graaff J.
Published: December 2007

In this study we determined the prevalence and distribution of Porphyromonas endodontalis in 26 families consisting of 107 subjects. P. endodontalis was present in 24% of the investigated subjects and was recovered most often from the dorsum of the tongue (50%). Isolation was also possible from the tonsils, the buccal mucosa, the saliva and the periodontal pocket. The usefulness of restriction endonuclease analysis as a typing method for this particular species was investigated by typing 19 isolates from unrelated individuals. All these isolates had unique restriction endonuclease patterns. The observed heterogeneity indicates that restriction endonuclease analysis is a sensitive measure of genetic dissimilarity between P. endodontalis isolates and is able to characterize individual isolates. Application of restriction endonuclease analysis to the obtained clinical isolates in this study shows the possibility of the presence of multiple clonal types within one subject. The DNA patterns of all P. endodontalis isolates from unrelated individuals were found to be distinct. In 3 families the DNA patterns of isolates from the mother and her child were indistinguishable. These data indicate the possibility of intrafamilial transmission of P. endodontalis.
Adhesin degradation: a possible function for a Prevotella loescheii protease?
Authors: Cavedon K. , London J.
Published: December 2007

Prevotella loescheii PK1295 produces at least 3 proteases that are separable by isoelectric focusing. One of these proteases, an enzyme with an isoelectric point at 8.5 and an Mr of 36,000, hydrolyzes the fimbria‐associated adhesin on P. loescheii responsible for coaggregation with Streptococcus oralis 34, as well as gelatin, casein and fibrin. The action of this protease may contribute to the detachment of P. loescheii from its streptococcal coaggregation partner and provide a mechanism for bacterial relocation in dental plaque.
Killing of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus by human polymorphonuclear leukocytes in serum and saliva
Authors: Holm A. , Kalfas S. , Holm S. E.
Published: December 2007

The ability of polymorphonuclear leukocytes from human peripheral blood to kill Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus was examined with fresh isolates and laboratory strains from each species (5 strains within each group) under different conditions. Bacterial cells were mixed with a polymorphonuclear leukocyte suspension in the presence of either active serum or heat‐inactivated serum or active serum together with sterile‐filtered saliva. Surviving bacteria were determined by counting the number of bacterial colony‐forming units in the mixtures after a 60‐min incubation at 37°C. Mixtures without polymorphonuclear leukocytes served as controls for the evaluation of the degree of killing of the bacteria. In general, A. actinomycetemcomitans resisted phagocytic killing to a greater extent than H. aphrophilus, and the killing of the former species mainly depended on the presence of heat‐labile serum components, probably complement factors. Laboratory strains of A. actinomycetemcomitans were more easily killed than fresh isolates. The presence of saliva in the reaction mixtures decreased the degree of killing. However, strain‐dependent variations in the killing were found under either condition. The leukotoxic activity of A. actinomycetemcomitans strains, determined by a [51Cr]‐release assay, was not correlated with the resistance of these strains to the phagocytic killing. The results point out a strain‐dependent difference in the ability of A. actinomycetemcomitans to evade the inflammatory response associated with polymorphonuclear leukocytes. This difference may constitute a potential virulence factor for this periodontopathogen. Furthermore, the leukotoxicity of the strains is not the main determinant that modifies the interaction of A. actinomycetemcomitans with human neutrophils.
Clonal analysis of Porphyromonas gingivalis by the arbitrarily primed polymerase chain reaction
Authors: Chen C. , Slots J.
Published: December 2007

Genetic analysis of Porphyromonas gingivalis strains may distinguish between virulent and nonvirulent strains and also may be used to trace individual strains in epidemiological studies. The present study examined the utility of the arbitrarily primed polymerase chain reaction for genotypic fingerprinting of P. gingivalis. DNA was extracted according to conventional methods. Ten‐base oligonucleotide primers with arbitrary sequences were used with the polymerase chain reaction to amplify P. gingivalis genomic DNA. The amplification products were analyzed by agarose gel electrophoresis. The primer GACCGCTTGT grouped 73 P. gingivalis strains into 23 genotypes, including 16 genotypes containing a single strain each. The primer AGGGGTCTTG identified 45 different genotypes, 33 of which contained a single strain. P. gingivalis strains ATCC 332771T and 381 belonged to the same genotype. Likewise, strains W50 and W83 were of the same genetic clone. The present study indicates that the arbitarily primed polymerase chain reaction represents a valuable and easy method for clonal analysis of P. gingivalis.
Evaluation of the E test for antimicrobial susceptibility testing of Porphyromonas gingivalis
Authors: Pajukanta R. , Asikainen S. , Forsblom B. , Piekkola M. , Jousimies‐Somer H.
Published: December 2007

The antimicrobial susceptibilities of 81 recent clinical Porphyromonas gingivalis isolates and two reference strains were determined by the E test, a new method, and were compared with the minimal inhibitory concentrations for these strains obtained by the reference agar dilution method on supplemented Brucella blood agar. The following agreements were obtained: benzylpenicillin 100%, ampicillin 96%, cefaclor 82%, cefuroxime 91%, erythromycin 93%, clindamycin 99%, tetracycline 66%i, doxycycline 89%, metronidazole 77% and ciprofloxacin 77%. Very major discrepancies were observed with ciprofloxacin. This study indicates that the E test is an acceptable method to determine the susceptibility of P. gingivalis for most antimicrobials.