bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenotypic profiles of lymphocyte populations isolated from rat major salivary glands
Authors: Montgomery P. C. , Skandera C. A. , O'Sullivan N. L.
Published: December 2007

Marker expression was studied in rat lymphocyte populations isolated from parotid, submandibular and sublingual salivary glands. Comparative data were also obtained for lacrimal gland and spleen populations. Increased percentages of Thy‐1+ cells were found in salivary gland populations when compared to spleen with the highest percentage noted for parotid gland. Thy‐1 percentages in parotid gland were comparable to those obtained with lacrimal gland. Salivary gland sIg, CD5 and CD8 cell percentages were lower than those obtained for lacrimal gland and splenic populations. The percentages of CD4‐bearing cells in submandibular and sublingual gland were lower than those found in parotid gland, lacrimal gland and spleen, and the CD4:CD8 ratios in parotid gland most closely approximated those in spleen. Increased percentages of Thy‐1+ lymphocytes coexpressing sIg and CD5 were obtained for all salivary gland cell populations when compared to spleen; however, percentages of salivary gland cells bearing these 3 markers were lower than noted for lacrimal gland, which contained the highest percentage. With respect to adhesion molecules, lymph node homing receptor (LNHR) and Peyer's patch homing receptor (PPHR) bearing cells were found in all glandular populations with the percentages of LNHR+ exceeding PPHR+ lymphocytes. Homing receptor bearing populations were highest in spleen and were present in equal proportions. LFA‐1 was expressed by all salivary gland cell populations in greater percentages than lacrimal gland, but lower than those in spleen. VLA‐4 and CD44 expression was higher in parotid gland and spleen than in submandibular and lacrimal gland. These data show that the phenotypes of resident lymphocytes in salivary gland tissues differ from lacrimal gland and spleen, as well as each other, and indicate that Thy‐1+ cells in glandular tissues bear both B and T cell markers. The adhesion molecule expression data suggest that these molecules may be utilized differently in various glandular tissues, potentially contributing to the variation in phenotypic profiles of resident glandular lymphocytes.
Host responses induced by co‐infection with Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in a murine model
Authors: Chen P. B. , Davern L. B. , Katz J. , Eldridge J. H. , Michalek S. M.
Published: December 2007

In this study, evidence is presented that mixed infection with the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans results in a synergistic effect in their pathogenicity and in their ability to induce humoral and cellular host responses. BALB/c mice were injected subcutaneously on the back with P. gingivalis ATCC 53977, A. actinomycetemcomitans 75 or a mixture of both bacteria. Samples of blood and fluid from abscesses formed at the site of injection (first degree) or distant from the injection site were collected for microbiologic analysis. Serum and spleens were obtained for evaluation of humoral and cellular responses to P. gingivalis and A actinomycetemcomitans. Mice injected with A. actinomycetemcomitans had first‐degree lesions only, whereas mice injected with P. gingivalis and A. actinomycetemcomitans had lesions at first‐ and second‐degree sites from which both bacterial species were isolated. A serum anti‐P. gingivalis response was induced in P. gingivalis‐injected mice, which was higher in mice injected with P. gingivalis and A. actinomycetemcomitans. This pattern was not seen in the anti‐A. actinomycetemcomitans response. Lymphoproliterative responses to phytohemagglutinin, Escherichia coli lipopolysaccharide and P. gingivalis of spleen cells from infected mice were decreased, especially following co‐infection. Furthermore, co‐infection of mice resulted in the greatest decrease in the number of CD5+, especially CD4+ lymphocytes.
Effect of host responses on the pathogenicity of strains of Porphyromonas gingivalis
Authors: Katz J. , Ward D. C. , Michalek S. M.
Published: December 2007

Porphyromonas gingivalis is implicated in the etiology of periodontitis. Strains of P. gingivalis have been classified as invasive or noninvasive based on their ability to form abscesses in a mouse model. The purpose of this study was to investigate the ability of P. gingivalis strains to cause abscesses and periodontal bone loss in an experimental rat model and the effect of serum and salivary responses on the pathogenicity of these strains. Subcutaneous injection of animals with P. gingivalis 33277, A7A1‐28, W50 or 381 resulted in abscesses in a higher percentage of mice than rats. P. gingivalis 33277 caused lesions at the site of injection, whereas strains A7A1‐28 and W50 induced abscesses at distant sites in both mice and rats. Local lesions were seen in rats injected with strain 381, whereas lesions formed distant from the site of injection in mice. When periodontal bone loss was assessed in the experimental rat model, animals challenged with 33277 had the highest amount of horizontal and vertical bone loss. Rats challenged with strain A7A1‐28, W50 or 381 had some or no periodontal bone loss compared with controls. Assessment of antibody responses to P. gingivalis in these animals revealed that rats challenged with 33277 had lower levels of serum immunoglobulin G (IgG) and especially salivary IgA antibody activity than A7A1‐28‐challenged rats. Serum IgG and in particular salivary IgA anti‐P. gingivalis responses were seen in W50‐ and 381‐challenged rats. These results indicate that the ability of P. gingivalis strains to cause abscesses does not relate directly to their periodontal pathogenicity as assessed by periodontal bone loss in the same animal model. The results further suggest the importance of salivary IgA antibody responses in protection against experimental periodontal bone loss after challenge with P. gingivalis.
Effect of oral bacteria on peripheral blood leukocyte interleukin‐6 and soluble interleukin‐6 receptor production
Authors: Lindemann R. A. , Kinder Haake S. A. , Kjeldsen M. , Avanessian A. B.
Published: December 2007

To determine the effect of pathogenic oral bacteria on interleukin 6 (IL‐6) and soluble IL‐6 receptor production, we measured their release by human peripheral blood mononuclear cells in vitro. Unseparated peripheral blood mononuclear cells, peripheral blood lymphocytes (monocyte depleted), pure T cells, or monocytes were cultured with Actinobacillus actinomycetemcomitans, Capnocytophaga gingivalis, Capnocytophaga ochracea, Fusobacterium nucleatum or Porphyromonas gingivalis for 24 h. Supernatants were tested for IL‐6 and soluble IL‐6 receptor by enzyme‐linked immunosorbent assay. Only monocytes and peripheral blood mononuclear cells responded with significant IL‐6 release in the presence of all bacteria tested. However, peripheral blood lymphocytes were capable of producing IL‐6 when activated by phytohemagglutinin or IL‐2 followed by bacteria, though substantially less than cultures containing monocytes. No bacteria tested increased soluble IL‐6 receptor release over spontaneous soluble IL‐6 receptor release. We conclude that monocytes release IL‐6 after contact with oral pathogens; however, soluble IL‐6 receptor from T cells and monocytes is constitutively produced and may modulate EL‐6 actions.
The demonstration of candidal pseudohyphae in salivary smears as a method of early diagnosis of oral candidiasis in patients with acute myeloid leukemia
Authors: Bergmann O. J.
Published: December 2007

To investigate the oral colonization of candidal pseudohyphae, a salivary smear method was tested against the use of mucosal smears in 10 patients with acute myeloid leukemia. The salivary smears showed to be reproducible and more sensitive than mucosal smears for the demonstration of Candida organisms. The salivary smear method was applied to another group of 10 patients with acute myeloid leukemia during a 28‐day period. According to swab cultures, 8 patients were colonized with Candida spp. on day 0, whereas 2 patients were uncolonized on day 0, and remained so. All colonized patients developed acute oral candidiasis. According to the salivary smear method, 5 patients were colonized with pseudohyphae as early as on day 0, whereas 3 patients became colonized with pseudohyphae within the first 7 days. Pseudohyphae were detected with a median of 4 days prior to the emergence of acute oral candidiasis, and the detection of acute oral candidiasis was associated with an increase in the quantity of pseudohyphae. The study suggests that the demonstration of Candidal pseudohyphae in salivary smears is an early indicator of subsequent development of acute oral candidiasis. Further studies are needed to clarify whether early treatment based on this finding will reduce the occurrence of acute oral candidiasis and disseminated candidiasis in these patients.
Adhesion of Porphyromonas gingivalis fimbriae to human gingival cell line Ca9‐22
Authors: Hirose K. , Isogai E. , Mizugai H. , Ueda I.
Published: December 2007

In this study, we examined the effects of selected environmental factors on the adhesion of Porphyromonas gingivalis fimbriae, an important structure involved in attachment of the bacteria to human gingival cells. The human gingival carcinoma cell line Ca9‐22 was grown in microculture plates, and adherence was detected by use of 125I‐labeled fimbriae. Adhesion was increased by changes in pH from 7.0–8.0, but was decreased by increase in the sodium chloride concentration above 0.15 M. Trypsin treatment of Ca9‐22 cells also augmented adhesion of the fimbriae to the cells. These results indicate that fimbrial adhesion to gingival cells is controlled by various environmental factors, and the data on trypsin treatment suggest that elevated levels of protease in the gingival sulcus, such as can occur with poor oral hygiene and gingivitis, may expose adhesion molecules on the gingival cell surface, thereby promoting the attachment of P. gingivalis fimbriae.
Distribution of a newly described species, Kingella oralis, in the human oral cavity
Authors: Chen C.
Published: December 2007

The oral distribution of Kingella oralis was investigated in 10 periodontally healthy subjects, 11 untreated adult periodontitis patients and 6 untreated localized juvenile periodontitis patients. From each subject, 6–8 each of supra‐ and subgingival tooth samples, 4 mucosa samples and a saliva sample were examined by culture for the presence of K. oralis. K. oralis was found in at least one oral site in 26 of the 27 study subjects, and in at least one tooth site in each of these 26 positive subjects. Its prevalence in dental plaque ranged from 23% to 59% in different subject groups. The mean percentage of K. oralis in total microbiota in the dental plaque ranged from 0.40% in the periodontally healthy group to 4.60% in localized juvenile periodontitis subjects. The organism was a significant species in a few periodontitis sites, constituting >5% of the total microbiota.
Interbacterial binding among strains of pathogenic and commensal oral bacterial species
Authors: Yao E. S. , Lament R. J. , Leu S. P. , Weinberg A.
Published: December 2007

Strong interspecies adherence was demonstrated among the periodontal pathogens Treponerna denticola, Bacteroides forsythus and Porphyromonas gingivalis, and between these pathogens and the commensal plaque organism Streptococcus crista. Adherence showed specificity and demonstrated saturation binding kinetics. Binding between B. forsythus and P. gingivalis appeared to be a unimodal protein‐protein interaction. Binding between the other organisms was at least bi‐modal involving interactions between combinations of proteins and carbohydrates with a variety of sugar specificities. Salivary molecules prevented adherence between T. denticola and S. crista, and serum eliminated B. forsythus binding to P. gingivalis. All other interactions occurred to some degree in the presence of serum and saliva. Such interbacterial binding interactions may be important in the establishment of periodontopathic plaque.
Characteristics of systemic antibody responses of nonhuman primates following active immunization with Porphyromonas gingivalis, Prevotella intermedia and Bacteroides fragilis
Authors: Giardino A. , Ebersole J. L. , Holt S. C.
Published: December 2007

Periodontal disease is an infectious disease manifested by the progressive change of a healthy resident commensal microbiota to a pathogenic one characterized by a specific microbiota. Thus, the prospect for the use of selected bacteria or their antigens as a vaccine to interfere with the microbial changes and resulting progression of periodontal tissue destruction has been proposed. As a first step in examining the use of bacterial antigens as immunogens in periodontitis, this study characterized the humoral immune response in Macaca fascicularis after systemic immunization with intact Porphyromonas gingivalis, Prevotella intermedia and Bacteroides fragilis. Parenteral immunization of the nonhuman primate with the intact bacteria resulted in the production of specific and significantly elevated levels of antibodies to P. gingivalis and P. intermedia, with the predominant isotype being immunoglobulin G (IgG). In contrast, the principal response to the nonoral, intestinal bacterium, B. fragilis, was of the IgM isotype. Immunization increased IgG, IgM and IgA antibody by 14–227 fold to P. gingivalis and 8–108 fold to P. intermedia. The level of serum IgA antibody increased (77–227 fold). The kinetics of the antibody response post‐immunization and post‐ligation differed with respect to each of the bacteria tested. IgG antibody to P. gingivalis increased through week 16 of the experiment and remained elevated above baseline through week 32. The IgG antibody level to P. intermedia peaked at 4 weeks following the third immunization and decreased post‐ligation to near baseline levels by week 16. Characterization of the immune response after active immunization in the nonhuman primate has demonstrated a substantial and specific increase in antibody response which was sustained for several weeks. The insights obtained from these studies should help optimize the potential for immunologic interference with progressing periodontitis.
Purification and properties of extracellular glucosyltransferase from Streptococcus bovis
Authors: Uezono Y. , Tsumori H. , Shimamura A. , Mukasa H.
Published: December 2007

Eight Streptococcus bovis strains were classified into 3 types on the basis of iso‐electric point (pI) and molecular mass (Mr) of extracellular glucosyltransferase. Strains ATCC 9809, 35034 and 43143 produced glucosyltransferase of pI 3.7 and Mr 165 kDa; strains ATCC 15351, 27960 and 33317 produced glucosyltransferase of pI 4.1 and Mr 140 kDa; strains ATCC 43085 and 43144 did not produce any glucosyltransferase. The glucosyltransferase from S. bovis 9809 was purified by Bio‐Gel hydroxyapatite chromatography and DEAE‐Toyopearl chromatography. The S. bovis 9809 glucosyltransferase was immunologically identical with the other 5 S. bovis glucosyltransferases and not related to mutans streptococcal glucosyl‐transferases. The specific activity, the optimum pH and the Km value for sucrose were 17.9 U/mg protein, 6.0 and 5.0 mM, respectively. The first 11 N‐terminal amino acid residues of the glucosyltransferase were DETSAVTLTRE, and the region was hydrophilic. The glucosyltransferases from S. bovis 9809 and 33317 synthesized from sucrose 1,6‐α‐d‐glucan with 9 and 2 mol% 1,3,6‐α‐branched glucose, respectively.
Induction of systemic murine B‐cell responses by Fusobacterium nucleatum and Porphyromonas gingivalis
Authors: Nunes I. P. , Jonsson R. , Jensen H. B. , Bakken V.
Published: December 2007

The purpose of this study was to examine the antigenic abilities of Fusobacterium nucleatum strain ATCC 25586 and Porphyromonas gingivalis strain W50 black inbred BALB/cABom mice immunized subcutaneously. Furthermore, we aimed to analyze whether the outer membranes (OM) and whole cells (WC) of F. nucleatum or P. gingivalis had an effect on the levels of antibody response and whether a combination of both could either enhance or suppress the B‐cell response. A single‐cell assay, solid‐phase enzyme‐linked immunospot (ELISPOT), was used to analyze the splenic B‐cell response (immunoglobulin A (IgA), IgG and IgM). Enzyme‐linked immunosorbent assay (ELISA) and immunoblotting were used to verify the specific antibody response in the sera. A statistically significant lower level of spontaneous antibody production was observed in the group immunized with P. gingivalis OM compared with groups immunized with F. nucleatum and saline. The specific antibody titers measured by ELISA indicated that the bacterial preparations were able to induce IgG and IgM response. The preparations containing P. gingivalis OM induced higher humoral response than the preparations containing P. gingivalis WC, but for F. nucleatum such a difference was not observed. The prominent proteins revealed had apparent molecular masses of 40 kDa for F. nucleatum and 115, 55–56 and 43 kDa for P. gingivalis; whereas the immunoreactive proteins were 70, 65 and 40 kDa for mice immunized with F. nucleatum and 115, 55–56, 43 and 33–34 kDa for mice immunized with P. gingivalis. Quantitative analysis of B‐cell response at the single cell level with ELISPOT revealed that some component(s) of P. gingivalis OM may have a suppressive ability on splenocytes incubated for a short time.
Susceptibility of biofilms of Streptococcus sanguis to chlorhexidine gluconate and cetylpyridinium chloride
Authors: Wilson M. , Patel H. , Fletcher J.
Published: December 2007

Biofilms of Streptococcus sanguis and planktonic cells of the organism were exposed to chlorhexidine gluconate and cetylpyridinium chloride, at concentrations used clinically, and survivors enumerated. S. sanguis exhibited a lower susceptibility to both antiseptics when it comprised a biofilm than when the organism was in the planktonic form. No viable bacteria were detectable after 5 min of exposure of planktonic cells to 0.2% (w/v) chlorhexidine gluconate or 0.05% (w/v) cetylpyridinium chloride, whereas viable bacteria survived in biofilms of S. sanguis even after exposure to these agents for 4 h. Older biofilms (7 days old) had similar susceptibilities to the antiseptics as younger biofilms (4 days old). Chlorhexidine achieved kills corresponding to approximately a 2 log10 reduction in the viable count of biofilms, containing approximately 107 colony‐forming units after 5 min of incubation, whereas the corresponding kills achieved by cetylpyridinium chloride amounted to approximately a 1 log10 reduction. However, on a molar basis, cetylpyridinium chloride was the more effective of the two antiseptics. Minimum inhibitory concentration determinations showed chlorhexidine gluconate to be more effective against S. sanguis than cetylpyridinium chloride. The results of this study have revealed that the minimum inhibitory concentration is not a reliable predictor of the relative effectiveness of antimicrobial agents against. S. sanguis biofilms.
Serum immunoglobulin G responses to various Actinobacillus actinomycetemcomitans serotypesinayoung ethnographically heterogeneous periodontitis patient group
Authors: Gmür R. , Baehni P. C.
Published: December 2007

Sera from young patients with periodontal diseases have been shown to often contain highly elevated antibody levels to Actinobacillus actinomycetemcomitans. in particular serotype b. Such responses were reportedly predominated by antibodies of the immunoglobulin G2 (IgG2) subclass. The aim of this study was to investigate an ethnically diverse group of 14 early‐onset periodontitis and 15 rapidly progressive periodontitis patients for the occurrence of elevated antibody titers against the five known A. actinomycetemcomitans serotypes, and to compare the patient's IgG subclass response profiles. Enzyme‐linked immunosorbent assays were used to measure both total IgG and subclass specific IgG titers. Twenty‐four subjects had markedly elevated total IgG levels against at least one serotype. The frequencies of high responses against serotypes a, b, c, d and e were 7, 11, 6, 4, and 4, respectively. Elevated antibody responses were predominated by IgG2, regardless of the serotype to which the response was directed. The serotype specificity of the host responses was further investigated by competitive binding studies with serotype‐specific monoclonal antibodies. Twelve sera were found to contain antibodies capable to strongly inhibit the binding of monoclonal antibodies against a single serotype; four other sera had antibodies against epitopes of two, and one serum against those of three serotypes. The findings document broad serotype diversity in an ethnically heterogeneous group of patients and indicate that strong antibody responses to A. actinomycetemcomitans are predominated by IgG2 regardless of the serotype of the infective agent.
Recognition of antigenic epitopes in lipopolysaccharide and protein from Actinobacillus actinomycetemcomitans by serum antibodies in untreated rapidly progressive periodontitis patients
Authors: Ou J.‐G. , Bainbridge B. , Gu K. , Sims T. J. , Whitney C. W. , Darveau R. P. , Chen H. A. , Houston L. S. , Page R. C.
Published: December 2007

Actinobacillus actinomycetemcomitans has been associated with early‐onset periodontitis, including the localized juvenile and rapidly progressive forms. The immunodominant antigens of A. actinomycetemcomitans recognized by rapidly progressive periodontitis patients remain unidentified. Sera from 22 patients with rapidly progressive periodontitis and 20 periodontally normal subjects were tested by enzyme‐linked immunosorbent assay (ELISA) for immunoglobulin G antibodies to whole‐cell sonicate, protein, purified lipopolysaccharide and lipopolysaccharide fractions of A. actinomycetemcomitans. The median titers of rapidly progressive periodontitis patients and control subjects to whole‐cell sonicate were 25.0 and 14.5 ELIS A units, respectively (not significantly different). Binding of antibody from patient sera occurred to both the lipopolysaccharide and the protein fractions, with greater binding to lipopolysaccharide than to protein. We show for the first time that patient sera contain antibodies that bind specifically to antigenic epitopes in lipid A and in the core carbohydrate of lipopolysaccharide that were previously considered to be inaccessible and unavailable, as well as to epitopes in the O side chains. Sera manifesting antibody titers 2–fold or greater than the median titer for control sera were judged to be seropositive. More patients were seropositive for lipid A than for any of the other antigen preparations studied, and the median titer for patient sera to lipid A but to none of the other purified lipopolysaccharide fractions was significantly elevated relative to control values. Of 22 patients, 10 were seropositive to whole‐cell sonicate, 7 to protein, 8 to lipopolysaccharide, 7 to the high‐molecular‐weight lipopolysaccharide‐polysaccharide fraction rich in O‐side chains, and 16 to lipid A. The core carbohydrate did not adhere to the test plate surface, and this precluded ELIS A measurements. However, when the core carbohydrate was used in the ELIS A inhibition assay, it reduced antibody binding to lipopolysaccharide‐coated plates by up to 45%, thereby demonstrating antibody binding to core carbohydrate. The core carbohydrate fraction from the Re mutant of Salmonella Minnesota known to contain no O‐side chains also inhibited binding of specific antibody to plates coated with A. actinomycetemcomitans lipopolysaccharide. Overall, there was extreme variation in responses among patients to the various antigen preparations, with no single pattern dominating. Lipopolysaccharide and its components appear to be the immunodominant epitopes, since most rapidly progressive periodontitis patients are seropositive for lipopolysaccharide and/or its components and they have higher titers relative to those for proteins.
Antibody reactive with Actinobacillus actinomycetemcomitans leukotoxin in early‐onset periodontitis patients
Authors: Califano J. V. , Pace B. E. , Gunsolley J. C. , Schenkein H. A. , Lally E. T. , Tew J. G.
Published: December 2007

The objective of this study was to determine whether a relationship exists between antibody reactive with the Actinobacillus actinomycetemcomitans leukotoxin and the severity of periodontal disease. Serum concentrations of antibody reactive with the leukotoxin were determined for 119 early‐onset periodontitis patients and 59 non‐periodontitis subjects using limiting dilution analysis on Western blots. Immunoglobulin G (IgG) antibody reactive with the A. actinomycetemcomitans leukotoxin ranged from undetectable to 29 jig/ml (mean = 3.13±0.97 μg/ml for the generalized early‐onset periodontitis and 2.17±0.86 μg/ml for the localized juvenile periodontitis patients vs 0.32±0.24 μg/ml for 59 non‐periodontitis controls), and the dominant subclass was IgGl. Analysis of the relationship between antibody reactive with A. actinomycetemcomitans sonicate, A. actinomycetemcomitans leukotoxin and attachment loss patterns indicates that seropositive generalized early‐onset periodontitis patients had decreased attachment loss compared with patients lacking this antibody. The statistical relationship appeared to be stronger for the sonicate than the purified leukotoxin. These data suggest that antibody reactive with A. actinomycetemcomitans leukotoxin may be protective in early‐onset periodontitis, but given that the sonicate appeared better than the leukotoxin alone, it is not likely that leukotoxin is the only antigen of importance to host defense.
Myeloperoxidase isoform activities released by human neutrophils in response to dental and periodontal bacteria
Authors: Miyasaki K. T. , Nemirovskly E.
Published: December 2007

Myeloperoxidase is an enzyme released by polymorphonuclear leukocytes which has been used, experimentally, as an indicator of periodontal disease activity when measured in gingival crevicular fluid. There are three myeloperoxidase isoforms: MPO I, MPOII and MPO III. We examined the activities of myeloperoxidase isoforms released by neutrophils in response to serum‐opsonized Actinobacillus actinomycetem‐comitans, Haemophilus aphrophilus, Eikenella corrodens, Capnocytophaga sputigena and Streptococcus sanguis. Isoform activities were determined using intermediate‐pressure liquid chromatography and microenzyme assay. A. actinomycetemcomitans stimulated higher levels of myeloperoxidase release than any other oral bacteria unless pre‐opsonized with serum (or protein‐A purified immunoglobulin) from an individual with localized juvenile periodontitis. Most oral bacteria stimulated the release of all myeloperoxidase isoforms with a profile enriched in MPO I and diminished in MPO III. Exceptionally, serum‐opsonized A. actinomycetemcomitans stimulated myeloperoxidase isoform release in proportion to the neutrophil granule constituency with or without localized juvenile periodontitis serum pre‐opsonization. Because myeloperoxidase isoform profiles reflect how neutrophils were stimulated, isoform analysis may refine future diagnostic tests based upon myeloperoxidase.
Occurrence of temperate bacteriophages in different Actinobacillus actinomycetemcomitans serotypes isolated from periodontally healthy individuals
Authors: Willi K. , Sandmeier H. , Asikainen S. , Saarela M. , Meyer J.
Published: December 2007

The occurrence of temperate bacteriophages was studied in 34 isolates of Actinobacillus actinomycetemcomitans derived from 27 periodontally healthy Finnish individuals both by lysis/plaque assays and by DNA hybridizations. In addition the serotype, the ribotype and the arbitrarily primed polymerase chain reaction (AP‐PCR) profile were determined for each A. actinomycetemcomitans strain. Fourteen isolates showed hybridization patterns very similar to that of a known lysogen when probed with the genome of the previously characterized temperate phage Aaø23. Only 6 of these 14 strains had produced lysis or single plaques on suitable indicator strains. Phage Aaø247 derived from one of these lysogens was indistinguishable from Aaø23 by electron microscopy, and the genomes showed highly related DNA hybridization patterns. The remaining 20 isolates exhibited hybridization patterns very different from that of Aaø23 DNA. Seven of these strains also gave lysis or single plaques, suggesting that 21 of the 34 strains were lysogenic. These data indicate that the prophages per se do not represent a virulence factor exclusively associated with periodontal disease. Presence of an Aaø23–related prophage correlated with serotype a and AP‐PCR type 1 of the bacterial host. This may indicate that Aa(J)23 and related phages have a limited host range.
CD29 expression on CD4+ gingival lymphocytes supports migration of activated memory T lymphocytes to diseased periodontal tissue
Authors: Seymour G. J. , Taubman M. A. , Eastcott J. W. , Gemmell E. , Smith D. J.
Published: December 2007

The cell surface phenotypes of CD4+ cells extracted from inflammatory periodontal disease tissues were analyzed using two‐ and three‐color immunofluorescence and flow cytometry. Cells extracted from both adult periodontal and localized juvenile periodontitis lesions showed a depressed CD4/CD8 ratio (1.0±0.1 adult periodontitis and 1.1 ±0.1 localized juvenile periodontitis) compared with cells recovered from normal/marginal gingivitis tissue (1.8 ±0.2) or with normal peripheral blood cells (2.1 ±0.1) or periodontal disease blood cells (2.1±0.1 and 1.7±0.1 for adult periodontitis and juvenile periodontitis, respectively). The monoclonal antibodies anti‐2H4 and anti‐4B4 were used to identify the CD45RA and CD29 antigens respectively on CD4+ T cells from the periodontal disease lesions. In peripheral blood, CD29+ cells accounted for 66–77% of the CD4+ population, and CD45RA+ cells accounted for 22–27% of the CD4+ subset. No differences in expression were found between peripheral blood lymphocytes from normal subjects and from periodontal disease patients. Two‐color analyses of lymphocytes from periodontal diseased tissues showed that 87–89% of the CD4+ population were CD29+ and that 70–79% of the CD4+ cells were CD45RA+. Normal tissues contained significantly fewer CD4+CD29+ cells (56±4%) and CD4+CD45RA+ cells (40±4%) on average, and few, if any double‐labelled cells could be accounted for. These data implied that a significant percentage of the CD4+ cells from the diseased tissues were both CD29+ and CD45RA+ and that these populations are found in quite different proportions in diseased periodontal tissue than in peripheral blood or nondiseased tissue. In further analyses using three‐color cytometry the mean percentage of CD4+CD29+CD45RA+ lymphocytes extracted from periodontal disease lesions was 43±9% of the CD4+ population. These results suggest that CD4+ T lymphocytes in periodontal disease not only demonstrate varying levels of maturity but also that the accumulation of CD4+ T cells within the periodontal tissues maybe a result of increased adhesion and transendothelial migration.
Cloning and sequencing of part of the S10 operon from Actinobacillus actinomycetemcomitans FDC Y4
Authors: Hayashida H. , Hotokezaka H. , Ohara N. , Kimura M. , Takagi O. , Yamada T.
Published: December 2007

We have cloned and sequenced the 5.2 kb EcoRI fragment that contained part of the S10 operon from Actinobacillus actinomycetemcomitans FDC Y4. The order of the ribosomal protein genes was identical to that of the S10 operon of Haemophilus influenzae and Escherichia coli. The deduced amino acid sequences of ribosomal proteins in this operon displayed significant homologies (65.3%‐100%) to those of H. influenzae, E. coli, Yersinia enterocolitica and Yersinia pseudotuberculosis. Phylogenetic trees obtained for these ribosomal proteins were similar to that obtained for 16S rRNA.
Mechanism of inhibition of acid production in Streptococcus mutans by sodium ions under strictly anaerobic conditions
Authors: Iwami Y. , Guha‐Chowdhury N. , Yamada T.
Published: December 2007

Acids excreted and intracellular levels of glycolytic intermediates during glucose metabolism in Streptococcus mutans NCTC 10449 under strictly anaerobic conditions were quantified in an attempt to understand the effect of sodium ions on bacterial acid production. In the presence of NaCl (0.15–0.30 M), the total amount of individual carboxylic acids excreted was inhibited by up to 31%. The intracellular level of fructose 1,6‐bisphosphate increased by 58% and levels of 3‐phosphoglycerate and pyruvate decreased by 46% and 12%, respectively. Sodium ions directly inhibited the activities of fructose 1,6‐phosphate aldolase and triose phosphate isomerase. This indicated that the glycolytic enzymes responsible for the catalysis of fructose 1,6‐bisphosphate to 3‐phosphoglycerate were inhibited. However, in spite of the expected reduction in acid production intracellularly, the intracellular pH actually decreased in the presence of sodium ions. It is possible that the low intracellular pH inhibits the activity of the glycolytic enzymes involved in the breakdown of fructose 1,6‐bisphosphate to 3‐phosphoglycerate.
Ribosomal RNA (rrn) operons in Streptococcus mutatis and nucleotide sequence of tRNAPro gene associated with rrnB
Authors: Novák J. , Shah G. R. , Zhu Y. , Caufield P. W.
Published: December 2007

Using a cloned 0.5‐kb probe containing an internal fragment of 23S ribosomal RNA from the rrnB operon of Streptococcus mutans, we analyzed various endo‐nuclease digests of the chromosomal DNA isolated from human‐derived strains of mutans streptococci. Thus far, the examined S. mutans strains exhibited five ribosomal operons. Here, we describe a ribotyping technique for S. mutans based on restriction and Southern blot analyses with the biotin‐labeled homologous probe and chemiluminescence detection. We cloned and sequenced a unique gene encoding tRNAPro downstream from 23S rRNA gene at the 3’end of the operon. Primers designed to the 3’end of the rrnB operon PCR‐amplified a 2.3‐kb DNA fragment in all tested strains. Restriction fragment length polymorphism analysis of the amplicon revealed a diversity of the single locus among S. mutans isolates, thus establishing a potential use of the technique for the molecular epidemiology of mutans streptococci.
Combined inhibitory effect of fluoride and hypothiocyanite on the viability and glucose metabolism of Streptococcus mutans, se retype c
Authors: Lenander‐Lumikari M. , Loimaranta V. , Hannuksela S. , Tenovuo J. , Ekstrand J.
Published: December 2007

The separate and combined effects of peroxidase‐generated hypothiocyanite (HOSCN/OSCN−) and F− ions on glucose uptake and growth of Streptococcus mutans ATCC 25175 were investigated. S. mutans cells were grown to late exponential or stationary growth phase, harvested, washed and suspended in 2.0 ml of sterilized human whole saliva supplemented with 10 mM D‐glucose. This saliva‐bacteria mixture was supplemented with 5–150 μM H2O2 at pH 5.0 or 6.5. At pH 5.0, up to 103±21 uM HOSCN/OSCN− was generated. After 20 h of incubation at 37°C, the saliva‐bacteria suspension exposed to HOSCN/OSCN− were plated on mitis salivarius agar plates and incubated anaerobically for 2 days. Identical experiments were made with F− ions (0.5, 1.0 and 5.0 mM). Both HOSCN/OSCN− and F− caused a significant dose‐dependent growth inhibition at pH 5.0, whereas no inhibition was observed at pH 6.5. When F‐ and HOSCN/OSCN− were added simultaneously at pH 5.0, an additive effect of growth inhibition was observed. In glucose incorporation experiments the bacteria‐saliva mixture was exposed to 1 μM HOSCN/OSCN−, 0.5 mM F− or both. F−, HOSCN/OSCN− or their combination in sterilized whole saliva at pH 5.0 caused 14.2, 67.8 and 74.2% inhibition, respectively. These observations indicate that F− and HOSCN/OSCN− ions have an additive inhibitory effect on S. mutans and therefore their combination is likely to be more antibacterial than either agent alone.
The role of the Streptococcus mutans glucosyltransferases in the sucrose‐dependent attachment to smooth surfaces: essential role of the gtfC enzyme
Authors: Tsumori H. , Kuramitsu H.
Published: December 2007

Previous results have indicated that the glucosyltransferase activities of mutans streptococci are required for sucrose‐dependent colonization of tooth surfaces. We have constructed mutants of Streptococcus mutans GS5 that are altered in varying combinations of the three gtf genes present in this organism. A quantitative in vitro sucrose‐dependent attachment system was used to demonstrate that the inactivation of the gtfC gene drastically reduced adherence to smooth surfaces. By contrast, inactivation of the gtfB gene resulted in a smaller, but significant, reduction in attachment while the gtfD mutant was only marginally affected. Furthermore, production of only the glucosyltransferase C enzyme allowed for attachment although at reduced levels compared to the wild‐type organism. The results from reintroduction of single copies of each of the gtf genes into a mutant of strain GS5 lacking glucosyltransferase activity also demonstrated the crucial role of the glucosyltransferase C enzyme in colonization. These results suggest a unique role for the glucosyltransferase C enzyme in the sucrose‐dependent colonization of tooth surfaces by S. mutans strains.
Cytokine messenger RNA expression in chronic inflammatory periodontal disease
Authors: Yamazaki K. , Nakajima T. , Kubota Y. , Gemmell E. , Seymour G. J. , Hara K.
Published: December 2007

It has previously been reported that, in periodontitis lesions, T cells with a memory/activated phenotype and with a type 2 cytokine profile accumulate in an oligoclonal fashion. Delineation of the role of cytokines in periodontal inflammation has, however, been complicated because of cross‐regulation and because of their overlapping and often redundant effects. The aim of this study was to examine messenger RNA levels for interferon γ, interleukin 4 (IL‐4), IL‐10, IL‐12 and IL‐13 in gingival tissues and peripheral blood mononuclear cells of patients with adult periodontitis. Reverse transcription polymerase chain reaction and subsequent image analysis was used to determine the level of mRNA for each cytokine. The mean expression of interferon γ mRNA was significantly higher in peripheral blood mononuclear cells than in gingival tissues. In contrast, the mean expression of IL‐10 mRNA was higher in gingival tissues than in peripheral blood mononuclear cells. This high expression of IL‐10 mRNA was, in fact, seen in only 7 gingival tissue samples with the majority of samples showing levels similar to peripheral blood mononuclear cells. There was no difference in the mean expression of IL‐12 p35 mRNA between gingival tissues and peripheral blood mononuclear cells. However, IL‐12 p40 mRNA was expressed higher in gingival tissues than in peripheral blood mononuclear cells in 6 out of 16 samples with significant difference of mean expression. Like IL‐10, gingival tissue samples and peripheral blood mononuclear cells expressed similar levels of IL‐12 p40 mRNA. There was no difference in the mean expression of IL‐13 in gingival tissues and peripheral blood mononuclear cells. Nevertheless, more peripheral blood mononuclear cell samples demonstrated high IL‐13 mRNA expression than gingival tissue samples. IL‐4 mRNA was weak but detectable in 3 gingival tissue samples. These results support the concept that cytokines form complex networks in periodontitis lesions and that their overlapping and redundant effects should be taken into account when considering the pathology of inflammatory periodontal disease. Dichotomous expression of IL‐10 and IL‐12 p40 mRNA in the periodontal lesion may be associated with disease entity.
Effect of sodium and potassium ions on intracellular pH and proton excretion in glycolyzing cells of Streptococcus mutans NCTC 10449 under strictly anaerobic conditions
Authors: Iwami Y. , Guha‐Chowdhury N. , Yamada T.
Published: December 2007

The effect of sodium and potassium ions on intracellular acid production and acid excretion by glycolyzing cells of Streptococcus mutans was examined. S. mutans NCTC 10449 grown under glucose‐limited and strictly anaerobic conditions in a continuous culture system was loaded with bis(carboxyethyl)‐carboxyfluorescein, a pH‐sensitive fluorescent dye, washed and suspended in 0.00–0.30 M NaCl/KCl solution. The dye allowed for the continuous monitoring of intracellular pH while proton excretion was measured simultaneously with a pH‐stat. Sodium ions inhibited and potassium ions, at low pH, accelerated the amount of measurable acid excreted extracellularly. In the presence of both NaCl and KCl, proton excretion following the addition of glucose was slightly higher or similar to that observed in the presence of 0.15 M KG alone. Sodium and potassium ions did not affect the proton‐ATPase enzyme or the intracellular level of ATP, suggesting that these ions did not directly effect proton pumping activity itself. The inhibition of proton excretion by sodium ions was considered to have probably occurred as a result of an indirect inhibition of proton‐ATPase activity by the low intracellular pH induced by sodium ions.
Bacteriocin production and sensitivity among coaggregating and noncoaggregating oral streptococci
Authors: Tompkins G. R. , Peavey M. A. , Birchmeier K. R. , Tagg J. R.
Published: December 2007

Twenty‐one oral Streptococcus isolates of known interbacterial coaggregation groups were tested against one another (as both producers and indicators) to detect bacteriocin‐like inhibitory activity. In agar‐based antagonism tests, seven strains produced small inhibitory zones (≤ 3 mm diameter) but in liquid medium, only strain Streptococcus gordonii DL1 (Challis) produced a detectable antibacterial action (bacteriocin STH1). Five strains were sensitive to bacteriocin STH1, but neither the production of nor the sensitivity to any of the antagonistic agents correlated with coaggregation groupings. Four strains (C219, 903, 118 and Wicky) developed stable resistance in response to the bacteriocin, whereas one isolate (strain 34) remained sensitive following repeated bacteriocin exposure. With one exception (strain 903), bacteriocin STH1‐sensitive strains were competent for genetic transformation, but not all competent strains were bacteriocin‐sensitive. Bacteriocin‐resistant derivatives of transformable strains exhibited decreased competence (80–90% reduction) compared with their parent strains.
Levels of specific immunoglobulin G to Porphyromonas gingivalis in gingival crevicular fluid are related to site disease status
Authors: Mooney J. , Kinane D. F.
Published: December 2007

Titers of immunoglobulin G (IgG) directed against Porphyromonas gingivalis in gingival crevicular fluid of 40 periodontitis patients were measured at three sites in each patient (healthy, gingivitis and periodontitis) by enzyme‐linked immunosorbent assay. When paired analyses were performed using Wilcoxon signed‐rank tests, periodontitis sites were found to have lower median titers than gingivitis sites. Both systemic and locally‐produced antibodies contribute to the overall gingival crevicular fluid antibody profile. Albumin, in contrast, is derived only from serum, and thus this protein serves as an indicator of serum contribution to gingival crevicular fluid. Correction was therefore made for systemic input to the gingival crevicular fluid IgG profile by expressing the results per unit of albumin. When this was done, periodontitis sites were also found to have significantly lower antibody levels than gingivitis sites. These findings suggest that a failure of local antibody production or reduction in quantities, by, for example, degradation by bacterial proteases, may contribute to the change from a gingivitis to a periodontitis lesion.
Current classification of the oral streptococci
Authors: Whiley R. A. , Beighton D.
Published: December 2007

The classification of the oral streptococci has long remained a difficult area of streptococcal taxonomy. This article reviews the current classification of these bacteria into four species groups, and each group is described in detail. The often confusing changes that have taken place in the classification, identification and nomenclature of the member species are reviewed against a historical background of gradually improving techniques and approaches, leading towards a natural classification based primarily on genotypic evidence. Identification schemes currently in use employing biochemical tests are also reviewed, together with alternative molecular approaches.
Genotyping shows different strains of mutans streptococci between father and child and within parental pairs in Swedish families
Authors: Emanuelsson I. Redmo , Li Y. , Bratthall D.
Published: December 2007

The purpose of this study was to investigate whether there was an intrafamilial similarity of mutans streptococcal strains in some Swedish families using chromosomal DNA fingerprinting. Plaque samples were obtained from buccal and occlusal surfaces of 25 three‐year‐old children, their mothers and 18 fathers. The colonization levels of mutans streptococci were estimated with the “Strip mutans” test, and caries experience was scored by decayed, missing and filled teeth or decayed, extracted and filled teeth. Interviews about medical history, diet regimes, breastfeeding and care of the child were performed. In 11 families isolates of mutans streptococci were detected in all three individuals. These isolates were serotyped by immunofluorescent technique and genotyped using the restriction endonuclease Hae III. The results showed that 5 children harbored mutans streptococci genotypes different from their parents. Six children showed genotypes identical to their mothers. None of the children harbored genotypes similar to their fathers, even though two thirds of the fathers had high or very high mutans streptococci levels. No matching of genotypes was observed within the 11 parental pairs. Mothers as primary caregivers with high “Strip mutans” scores were more often observed in the group with identical genotypes within the mother‐child pairs, the “matching group”, than in the “no‐matching group”. These data indicate that the fathers and the children had not acquired each others' strains of mutans streptococci nor had the spouses. The results suggest that the children acquired mutans streptococci both from outside and inside the family.
Differential expression of interleukin‐8 and intercellular adhesion molecule‐1 by human gingival epithelial cells in response to Actinobacillus actinomycetemcomitans or Porphyromonas gingivalis infection
Authors: Huang G. T.‐J. , Haake S. Kinder , Kim J.‐W. , Park N.‐H.
Published: December 2007

Little is known regarding the molecules expressed by gingival epithelial cells that are involved in initiating and maintaining inflammation following the interaction with periodontal pathogens. Thus, we investigated the effect of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis infection on the expression of neutrophil chemoattractant interleukin 8 (IL‐8) and the adhesion molecule intercellular adhesion molecule‐1 by gingival epithelial cells. The data revealed that both IL‐8 and intercellular adhesion molecule‐1 expression increased after infection with A. actinomycetemcomitans (IL‐8: 2‐ to 7‐fold; intercellular adhesior molecule‐1: 2.5‐ to 3.7‐fold). IL‐8 secretion reached a maximal level 6 h after the infection and the expression subsequently decreased to basal level. The increased cell surface intercellular adhesion molecule‐1 expression started at 4 h after infection and reached a maximal level 14 h after the infection. In contrast, the expression of both molecules rapidly decreased 2 h after challenge with P. gingivalis. This opposite influence of A. actinomycetemcomitans and P. gingivalis infection on the expression of IL‐8 and intercellular adhesion molecule‐1 by gingival epithelial cells suggests that A. actinomycetemcomitans infection may initiate the recruitment of neutrophils, whereas the P. gingivalis infection may retard this process and therefore demonstrate a distinct perspective of virulence.