Acid tolerance and acid-neutralizing activity of Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum

The tolerance to acid and the acid-neutralizing activity of three important periodontopathic bacteria, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum were studied. P. gingivalis strains grew only at neutral pH and did not utilize glucose, whereas strains of P. intermedia and F. nucleatum could grow under acidic conditions and increased their growth by utilizing glucose. P. gingivalis tended to raise the culture pH during growth. P. intermedia and F. nucleatum raised the culture pH during growth in the absence of glucose, while in the presence of glucose they decreased the pH. Resting cell suspensions of all the bacteria raised the pH in the presence of tryptone and casamino acids. Acid-neutralizing activity was confirmed by measuring base production at a fixed pH with a pH-stat. During neutralization, the cells produced cytotoxic substrates, ammonia and organic acids (butyric, isobutyric and isovaleric acids by P. gingivalis ; isovaleric and succinic acids by P. intermedia ; propionic and butyric acids by F. nucleatum ). These findings suggest that deamination of amino acids into ammonia and organic acids occurs simultaneously with base production, resulting in acid neutralization. These results could partially explain the survival of P. intermedia and F. nucleatum in both supragingival and subgingival plaque and the apparent restriction of P. gingivalis to subgingival plaque. The former bacteria may aid in creation of an environment fostering colonization of subgingival plaque by P. gingivalis.     

Dipeptide utilization by the periodontal pathogens Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Fusobacterium nucleatum

Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Fusobacterium nucleatum, which can frequently be isolated from periodontal pockets, preferentially utilize proteins and peptides as growth substrates. In this study, we determined the size of peptide that is preferentially utilized as a source of energy and material for cell growth by P. gingivalis, P. intermedia, P. nigrescens and F. nucleatum using various sizes of poly amino acids consisting of two to approximately 100 molecules of aspartate or glutamate. Resting cells of P. gingivalis, P. intermedia and P. nigrescens utilized aspartylaspartate, while cells of P. gingivalis and F. nucleatum utilized glutamylglutamate. The addition of aspartylaspartate to the culture medium increased the growth of P. gingivalis, P. intermedia and P. nigrescens, while the addition of glutamylglutamate promoted the growth of P. gingivalis and F. nucleatum. These results clearly indicate that dipeptides such as aspartylaspartate and glutamylglutamate can be utilized as growth substrates for P. gingivalis, P. intermedia, P. nigrescens and F. nucleatum.     

Herpesviruses in human periodontal disease

Recent studies have identified various herpesviruses in human periodontal disease. Epstein–Barr virus type 1 (EBV‐1) infects periodontal B‐lymphocytes and human cytomegalovirus (HCMV) infects periodontal monocytes/macrophages and T‐lymphocytes. EBV‐1, HCMV and other herpesviruses are present more frequently in periodontitis lesions and acute necrotizing ulcerative gingivitis‐lesions than in gingivitis or periodontally healthy sites. Reactivation of HCMV in periodontitis lesions tends to be associated with progressing periodontal disease. Herpesvirus‐associated periodontitis lesions harbor elevated levels of periodontopathic bacteria, including Acrinobacillus actinomycetemcomitans , Porphyromonas gingivalis , Bacteriodes forsythus , Prevotella intermedia , Prevotella nigrescens and Treponema denticola . It may be that active periodontal herpesvirus infection impairs periodontal defenses, thereby permitting subgingival overgrowth of periodontopathic bacteria. Alteration between latent and active herpesvirus infection in the periodontium might lead to transient local immunosuppression and explain in part the episodic progressive nature of human periodontitis. Tissue tropism of herpesvirus infections might help explain the localized pattern of tissue destruction in periodontitis. Absence of herpesvirus infection or viral reactivation might explain why some individuals carry periodontopathic bacteria while still maintaining periodontal health. Further studies are warranted to delineate whether the proposed herpesvirus‐periodontopathic bacteria model might account for some of the pathogenic features of human periodontal disease.     

Induction of calprotectin release by Porphyromonas gingivalis lipopolysaccharide in human neutrophils

Calprotectin, a major cytosolic protein of leukocytes, is detected in neutrophils, monocytes/macrophages, and epithelial cells. This protein is known to be a marker for several inflammatory diseases and is detected in inflammatory gingival tissue with periodontal disease. Recently, we found that the calprotectin level in gingival crevicular fluid from periodontitis patients was significantly higher than that of healthy subjects. However, the regulation of calprotectin in periodontal disease is unclear. In the present study, we investigated the effect of lipopolysaccharides of periodontopathic bacteria on calprotectin release from human neutrophils. Neutrophils from healthy donors were treated with lipopolysaccharides from Porphyromonas gingivalis (P-LPS), Actinobacillus actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, and Escherichia coli. Calprotectin of neutrophil was identified by immunoblotting and calprotectin amount was determined by ELISA. Two subunits (10 and 14 kDa) of calprotectin were observed in the cell and medium fractions from neutrophils. P-LPS increased calprotectin release from seven to 16 times the control level after 30 min and its effect appeared in a dose-dependent manner (10-1000 ng/ml). Lipopolysaccharides from A. actinomycetemcomitans, P. intermedia, F. nucleatum, and E. coli also induced calprotectin release from neutrophils. These results suggest that lipopolysaccharides from periodontopathic bacteria induce calprotectin release from human neutrophils.     

Inhibitory effects of macrocarpals on the biological activity of Porphyromonas gingivalis and other periodontopathic bacteria

BACKGROUND/AIMS: Macrocarpals, which are phloroglucinol derivatives contained in eucalyptus leaves, exhibit antimicrobial activity against a variety of bacteria including oral bacteria. This study examined effects of macrocarpals A, B, and C on periodontopathic bacteria, especially Porphyromonas gingivalis. METHODS: Macrocarpals A, B, and C were purified from a 60% ethanol-extract of Eucalyptus globules leaves. To investigate antibacterial activity, representative periodontopathic bacteria were cultured in media with or without various amounts of macrocarpals; subsequently, the optical density at 660 nm was measured. Macrocarpal inhibition of P. gingivalis Arg- and Lys-specific proteinases was assessed by spectrofluorophotometric assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The effect of macrocarpals on P. gingivalis binding to saliva-coated hydroxyapatite beads was examined with (3)H-labeled P. gingivalis. RESULTS: Growth of P. gingivalis was inhibited more strongly than growth of Prevotella intermedia or Prevotella nigrescens and Treponema denticola by macrocarpals, however, Actinobacillus actinomycetemcomitans and Fusobacterium nucleatum were much more resistant. Macrocarpals inhibited P. gingivalis Arg- and Lys-specific proteinases in a dose-dependent manner. The enzyme-inhibitory effect of macrocarpals was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis in which hemoglobin degradation by P. gingivalis proteinase was inhibited by macrocarpals. P. gingivalis binding to saliva-coated hydroxyapatite beads was also strongly attenuated by macrocarpals. CONCLUSIONS: Macrocarpals A, B and C demonstrated antibacterial activity against periodontopathic bacteria. Among tested bacteria, P. gingivalis displayed the greatest sensitivity to macrocarpals; additionally, its trypsin-like proteinase activity and binding to saliva-coated hydroxyapatite beads were inhibited by macrocarpals. These results indicate that eucalyptus leaf extracts may be useful as a potent preventative of periodontal disease.     

Interleukin-1alpha stimulation in monocytes by periodontal bacteria: antagonistic effects of Porphyromonas gingivalis

Periodontal pathogenic bacteria are associated with elevated levels of interleukin-1alpha (IL-1alpha) but it is unclear if all species can induce cytokine production equally. Porphyromonas gingivalis may be able antagonize IL-1alpha induced by other species through the activity of its proteases or lipopolysaccharide (LPS). Monomac-6 cells and primary human monocytes were treated with culture supernatants from Porphyromonas gingivalis, Fusobacterium nucleatum, Campylobacter rectus, Actinobacillus actinomycetemcomitans, Prevotella intermedius, Veillonella atypical and Prevotella nigrescens. IL-1alpha protein levels were measured after 6 h of incubation. In addition, monocytes were co-stimulated with supernatants from P. gingivalis and other bacteria. The role of P. gingivalis proteases was tested using Arg-X and Lys-X mutant strains. The role of LPS was investigated using purified P. gingivalis LPS and polymixin depletion. All species tested induced significant IL-1alpha production, but P. gingivalis was the weakest. Co-stimulation of monocytes with P. gingivalis antagonized the ability of other bacterial species to induce IL-1alpha production. This effect was at its greatest with C. rectus (resulting in a 70% reduction). Gingipain mutant strains and chemical inhibition of protease activity did not reduce antagonistic activity. However, 100 ng/ml of P. gingivalis LPS can reproduce the antagonistic activity of P. gingivalis culture supernatants. Periodontitis-associated bacterial species stimulate IL-1alpha production by monocytes. P. gingivalis can antagonize this effect, and its LPS appears to be the crucial component. This study highlights the importance of mixed infections in the pathogenesis of periodontal disease because reduction of pro-inflammatory cytokine levels may impair the ability of the host to tackle infection.     

The distribution of periodontopathic bacteria among Japanese children and their parents

OBJECTIVE AND BACKGROUND: It is not well known how periodontopathic bacteria colonize in the oral cavity during childhood. The purpose of this study was to investigate the distribution of periodontopathic bacteria in oral cavities of children and their parents and the relationship between the bacterial findings and clinical parameters. METHODS: Fifty-six children (mean age: 8.3 +/- 3.5, range: 1-15 years), including 15 with deciduous dentition, 26 with mixed dentition and 15 with permanent dentition, and their parents participated in this study. Whole saliva and dental plaque of the children and whole saliva of their parents were collected for detection of seven species of periodontopathic bacteria (Actinobacillus actinomycetemcomitans, Tannerella forsythensis (Bacteroides forsythus), Campylobacter rectus, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Treponema denticola) using the polymerase chain reaction method. Clinical parameters including simplified Oral Hygiene Index and Papillary-Marginal-Attachment Index were recorded for the children and their accompanied parents. RESULTS: The detection frequencies of T. forsythensis, C. rectus, P. nigrescens, T. denticola, A. actinomycetemcomitans and P. gingivalis in the oral cavities of children were 42.9%, 94.6%, 42.9%, 48.2%, 1.8% and 8.9%, respectively. T. forsythensis, P. gingivalis and T. denticola were detected more frequently in the saliva of parents (54.8%, 54.8%, 88.1%, respectively) than in the saliva of children (25.5%, 7.3%, 41.8%, respectively). Different detection frequencies of P. nigrescens were found among the oral cavities of children with deciduous, mixed and permanent dentitions. In mixed dentition, females harbored T. forsythensis more frequently than males did. Children who harbored T. forsythensis, P. intermedia, P. nigrescens and T. denticola showed high scores for oral debris measurement by simplified Oral Hygiene Index. T. forsythensis, P. intermedia and P. nigrescens were detected more frequently in children whose parents were positive for these pathogens than in children whose parents were negative. CONCLUSIONS: High plaque retention seems to promote the colonization of periodontal pathogens in the oral cavities of children. T. forsythensis, P. intermedia and P. nigrescens were detected more frequently in the oral cavities of children whose parents already harbored these bacteria. Familial transmission of these bacteria is suggested.     

Quantitative detection of periodontal pathogens using real-time polymerase chain reaction with TaqMan probes

Quantitative analysis, with identification of periodontopathic bacteria, is important for the diagnosis, therapeutic evaluation and risk assessment of periodontal disease. We developed a highly sensitive and specific method using real-time polymerase chain reaction (PCR) to detect and quantify six periodontal bacteria: Porphyromonas gingivalis, Tannerella forsythia, Actinobacillus actinomycetemcomitans, Treponema denticola, Prevotella intermedia, and Prevotella nigrescens. Species-specific TaqMan probe/primer sets were designed according to 16S ribosomal RNA gene sequences. Plaque and tongue debris specimens were collected from 10 patients with advanced periodontitis and 10 periodontal healthy individuals and analyzed. All species, except for P. nigrescens, were detected in samples from diseased sites in significantly greater numbers than in those from healthy sites, whereas greater numbers of P. nigrescens were found in the controls. These results suggest that the present real-time PCR method with the designed probe/primer sets enabled sensitive detection of the six periodontal bacteria, and may also assist future microbial studies of periodontal diseases.     

Fusobacterium nucleatum involvement in adult periodontitis and possible modification of strain classification

BACKGROUND: This investigation was designed to evaluate the involvement of Fusobacterium nucleatum clinical strains in adult periodontitis by subspecies and expression of hemagglutination activity. METHODS: Forty-nine Fusobacterium strains were isolated from 40 sites in 40 subjects presenting with adult periodontitis. F. nucleatum subspecies identification was based on the electrophoretic migration of glutamate dehydrogenase and 2-oxoglutarate reductase. Hemagglutination activity and inhibition by galactose were tested on sheep erythrocytes. RESULTS: The 49 isolates belonged to the F. nucleatum species with a predominance of the nucleatum (34.7%) followed by the vincentii (26.5%) subspecies. In parallel, 71% of the strains belonging to the nucleatum subspecies were preferentially associated with Porphyromonas gingivalis. Prevotella intermedia/nigrescens detection was essentially correlated with identification of Fusobacterium nucleatum subspecies vincentii. No correlation was established between any particular subspecies and the pathogenicity factors tested (hemagglutination and production of short-chain fatty acids). On the other hand, significant predominance (65%, P= 0.017) of strongly hemagglutinating strains (titre > or =8 U) was observed in the sites where Porphyromonas gingivalis, Prevotella intermedia/nigrescens and/or Campylobacter rectus were not detected. These strains also showed higher butyric acid production. CONCLUSION: The importance of the adherence factors for Fusobacterium nucleatum strains and their multimodal aspect may indicate a higher pathogenicity or a higher involvement of certain strains and could lead to a classification of these strains, which is more closely related to their implication in the development of periodontal disease.     

Flow cytometry to monitor phagocytosis and oxidative burst of anaerobic periodontopathogenic bacteria by human polymorphonuclear leukocytes

The reduced susceptibility to phagocytosis found among some periodontopathogenic anaerobes may account for the differences between invasive and non-invasive strains. We applied flow cytometry as a powerful tool to analyze and quantify phagocytosis using standardized cultures of oral anaerobes (Porphyromonas gingivalis, Prevotella intermedia, P. nigrescens, Capnocytophaga gingivalis, C. ochracea, C. sputigena, Fusobacterium nucleatum and Peptostreptococcus micros) and heparinized whole blood. Bacteria were labeled by a fluorescein-methylester and their esterase activity, resulting in green fluorescence. Ingested bacteria could be detected easily and quantified by a shift towards green fluorescence in the PMNL population involved and a concomitant decrease in the bacterial population. Furthermore, the oxidative burst of PMNLs was detected in parallel assays using the dye DHR123 which becomes fluorescent upon oxidation during the oxidative burst process. We found a great diversity in phagocytosis susceptibility determined by estimating the portion of phagocytosing PMNLs, ranging from 10.6% (strain W83) to > 99.4% (e.g. ATCC 33277T) in P. gingivalis and from 15.9% (strain MH5) to > 95% (ATCC 33563T) in P. nigrescens. In contrast, almost all P. intermedia strains as well as the representatives of the other anaerobic, putative periodontopathic species tested showed no or only moderate resistance in the phagocytosis assay. Comparison of clinical data of patients and the extent of phagocytosis resistance of the corresponding P. gingivalis strains suggests that this virulence factor may contribute to the clinical outcome.     

Identification of periodontopathic bacteria DNA from periodontitis-involved gingival tissue using a PCR method

The purpose of this study was to determine the presence of periodontopathic bacteria DNA in the granulation tissue of periodontally involved gingival tissue. Forty periodontitis patients were examined. Subgingival plaque and saliva samples were collected from the patients before surgery. Then, granulation tissue was also collected during surgery. Another 20 patients, who had more than 4 mm in probing pocket depth, were also examined as a control. They received only initial treatment without periodontal surgery. Plaque and saliva samples were also collected from them. Seven periodontopathic bacteria, Porphyromonas gingivalis, Bacteroides forsythus, Toreponema denticola, Campylobacter rectus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Prevotella nigrescens, were detected by a PCR method from these samples of all patients. As clinical parameters, probing pocket depth, clinical attachment level, and bleeding on probing were recorded. One year after surgery, sampling of subgingival plaque and saliva, and measurement of clinical parameters were performed on the patients. The DNA of periodontopathic bacteria was detected in the granulation tissue of 29 out of 40 patients. P. gingivalis, B. forsythus, T. denticola, C. rectus, A. actinomycetemcomitans, P. intermedia and P. nigrescens were detected in 23, 11, 12, 9, 3, 2 and 1 subject(s) respectively. The sites with undetectable level of any periodontal pathogens at one year after surgery showed a clinical attachment gain of 2.44 mm, while those that showed detectable pathogen levels had only a 0.77 mm gain. Our results indicated that the removal of granulation tissue contributed to eliminating periodontal pathogens and to avoiding re-infection by those bacteria. Complete eradication of periodontopathic bacteria would be necessary for successful periodontal treatment.     

Prevalence of periodontopathic bacteria in aggressive periodontitis patients in a Chilean population

BACKGROUND: Actinobacillus actinomycetemcomitans is considered a major etiologic agent of aggressive periodontitis (AgP). Other periodontopathic bacteria such as Porphyromonas gingivalis are also suspected of participating in aggressive periodontitis although the evidence to support this is controversial. The aim of the present study was to determine the prevalence of eight periodontopathic bacteria in Chilean patients with AgP. METHODS: Subgingival plaque samples were collected from 36 aggressive, 30 localized, and six generalized periodontitis patients. Samples from 17 advanced chronic periodontitis (CP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in prereduced transport fluid (RTF) and cultured. Periodontal bacteria were primarily identified by colony morphology under stereoscopic microscope and rapid biochemical tests. The identity of some bacterial isolates was confirmed by colony polymerase chain reaction (PCR). RESULTS: AgP showed a significatively higher prevalence of C. rectus than CP (P = 0.036). The only statistical difference found was for C. rectus. Patients with AgP showed a higher, but not statistically significant, prevalence of P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. A similar prevalence in both groups of patients was observed for F. nucleatum and P. intermedia/nigrescens, and A. actinomycetemcomitans was less prevalent in AgP than CP patients. In localized AgP, P. intermedia/nigrescens, E. corrodens, F. nucleatum, and P. micros were the more prevalent pathogens in contrast to generalized AgP patients who harbored A. actinomycetemcomitans, P. gingivalis, and Capnocytophaga sp. as the most prevalent bacteria. CONCLUSIONS: C. rectus, P. gingivalis, E. corrodens, P. micros, and Capnocytophaga sp. were the most predominant periodontopathic bacteria of AgP in this Chilean population, but the only statistical difference found here between AgP and CP was for C. rectus, suggesting that the differences in clinical appearance may be caused by factors other than the microbiological composition of the subgingival plaque of these patients. In this study, the prevalence of A. actinomycetemcomitans was much lower than that of P. gingivalis.     

Inhibition of Actinobacillus actinomycetemcomitans leukotoxicity by bacteria from the subgingival flora

Actinobacillus actinomycetemcomitans produces a pore-forming leukotoxin that lyses human polymorphonuclear leukocytes and monocytes. Certain proteolytic bacteria may coexist with A. actinomycetemcomitans in periodontal pockets. We aimed therefore to examine whether oral bacteria can modify the leukotoxicity of A. actinomycetemcomitans. A total of 55 strains representing 45 bacterial species of the subgingival flora were tested. Each strain was incubated with the highly toxic strain of A. actinomycetemcomitans HK 1519 and the leukotoxic activity of the suspension against human polymorphonuclear leukocytes was determined from the activity of the lactate dehydrogenase released upon lysis of the leukocytes. Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, Prevotella melaninogenica and Prevotella loeschii inhibited the leukotoxicity of A. actinomycetemcomitans cells as well as the activity of leukotoxin purified from the same strain. The bacterial strains without the ability to block leukotoxic activity also failed to destroy pure leukotoxin even after 5 h of incubation. The proteolytic degradation of leukotoxin by P. gingivalis was mainly dependent on the activity of the enzymes R- and K-gingipains. P. intermedia and P. nigrescens also degraded the leukotoxin by enzymes. The results imply a role of the periodontal microflora in modifying the virulence of A. actinomycetemcomitans by destroying its leukotoxin.     

The relationship of Prevotella intermedia, Prevotella nigrescens and Prevotella melaninogenica in the supragingival plaque of children, caries and oral malodor

PURPOSE: A relationship between the distribution of periodontal bacteria species and malodor in children has not been sufficiently investigated. The present study was undertaken to determine the presence of 3 periodontopathic bacteria (Prevotella spp. P. intermedia, P. nigrescens, P. melaninogenica) in the supragingival plaques of 3 to 16-year-old children with different oral health conditions and oral malodor. METHODS: The number of decayed and filled primary teeth (df) and Decayed, Missing and Filled permanent teeth (DMF), Papillary Marginal and Attached gingivitis (PMA) index, Oral Hygiene Index (OHI), and oral malodor of each subject were determined prior to the collection of supragingival plaques. Three periodontopathic bacteria (P. intermedia, P. nigrescens, P. melaninogenica) in supragingival plaques were detected by using an immunoslot blot assay with monoclonal antibodies specific for each microorganism. FINDINGS: The frequencies of periodontopathic bacteria in children with and without caries were not significantly different from each other. Positivity for P. intermedia, but not for P. nigrescens or P. melaninogenica was correlated with oral malodor. Oral malodor was also correlated with the debris index, a component of OHI. The group with the higher OHI showed a higher prevalence of periodontopathic bacteria. For the 3 periodontopathic bacteria in the subjects tested, plaques positive for any of them were not age related. However the frequencies of all 3 periodontopathic bacteria were the highest in the 3-6-year olds. CONCLUSION: The supragingival plaques in children can harbor 3 species of periodontopathic bacteria, P. intermedia, P. nigrescens, and P. melaninogenica.     

Herpesviruses, the missing link between gingivitis and periodontitis?

Herpesviruses appear to assume a major etiopathogenic role in various types of destructive periodontal disease. Human cytomegalovirus (HCMV), Epstein-Barr virus (EBV) and HCMV-EBV co-infection are closely associated with disease-active periodontitis in juveniles and adults, with acute necrotizing ulcerative gingivitis in children, and with periodontal abscesses. In particular, HCMV reactivation in periodontitis lesions seems to be linked to advancing disease. HCMV infects periodontal monocytes/macrophages and T-lymphocytes, and EBV infects periodontal B-lymphocytes. Herpesvirus-infected inflammatory cells generate a great variety of pro-inflammatory cytokines and may possess diminished ability to defend against bacterial challenge. Herpesvirus-associated periodontal sites tend to harbor elevated levels of periodontopathic bacteria, including Dialister pneumosintes, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Prevotella nigrescens, Treponema denticola, Campylobacter rectus and Actinobacillus actinomycetemcomitans. In summary, the available data suggest that periodontitis occurs more frequently and progresses more rapidly in herpesvirus-infected than in non-infected periodontal sites. An infectious disease model based on herpesvirus-bacteria-host immune response interactions is presented to explain how a gingivitis lesion or a stable periodontal site with increased probing depth may convert into a tissue-destroying periodontitis lesion.     

Relationship between herpesviruses and adult periodontitis and periodontopathic bacteria.

BACKGROUND: Various mammalian viruses and specific bacteria seem to play important roles in the pathogenesis of human periodontitis. This study examined the relationship between subgingival herpesviruses and periodontal disease and potential periodontopathic bacteria in 140 adults exhibiting either periodontitis or gingivitis. METHODS: A nested-polymerase chain reaction (PCR) method determined the presence of Epstein-Barr virus type 1 and type 2 (EBV-1, EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) and a 16S rRNA PCR detection method identified Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. RESULTS: Using a logistic analysis, EBV-1 showed significant positive association with P. gingivalis (odds ratio [OR] 3.37), and with coinfections of P. gingivalis and P. intermedia (OR 4.03); P. gingivalis and B. forsythus (OR 3.84); P. gingivalis and T. denticola (OR 4.17); P. gingivalis, B. forsythus, and T. denticola (OR 4.06); and P. gingivalis, P. nigrescens, and T. denticola (OR 3.29). EBV-1 also showed positive association with severe periodontitis (OR 5.09), with increasing age (OR 1.03), and with periodontal probing depth at the sample sites (OR 1.77). HCMV was positively associated with coinfections of P. gingivalis and P. nigrescens (OR 3.23); P. gingivalis, B. forsythus, and P. nigrescens (OR 3.23); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.59); with severe periodontitis (OR 4.65); and with age (OR 1.03). Patients with mixed viral infections revealed significant associations with P. gingivalis (OR 2.27), and with coinfections of P. gingivalis and B. forsythus (OR 2.06); P. gingivalis and P. nigrescens (OR 2.91); P. gingivalis, B. forsythus, and P. nigrescens (OR 2.91); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.70) with the clinical diagnosis of slight (OR 3.73), moderate (OR 3.82), or severe periodontitis (OR 4.36), and with probing depth at the sample sites (OR 1.39). HSV and EBV-2 showed no significant associations with any of the variables tested. CONCLUSIONS: The results indicate that subgingival EBV-1, HCMV, and viral coinfections are associated with the subgingival presence of some periodontal pathogens and periodontitis. Herpesviruses may exert periodontopathic potential by decreasing the host resistance against subgingival colonization and multiplication of periodontal pathogens.     

Effect of periodontal treatments on serum IgG antibody titers against periodontopathic bacteria

Abstract. Serum IgG antibody titers to 7 periodontopathic bacteria in periodontitis patients were measured at the Is1 visit and after various periodontal treatments with clinically successful improvement, in order to evaluate what kind of factors are associated with changes of serum antibody titers. 20 patients (10 male and 10 female from 23 to 61 years old) with adult, rapidly progressive periodontitis were enrolled in this study. All patients received initial preparation and most of them also underwent surgical procedure. After the treatments, the mean probing pocket depths decreased from 3.72 mm to 1.56 mm. Serum samples were collected from patients at the initial and final examinations. Serum IgG antibody titers against sonicated antigens of Porphyromonas gingivalis FDC 381, Prevotella intermedia ATCC 25611. Prevotella loescheii ATCC 15930. Fusobacterium nucleatum subspecies nucleatum ATCC 25586. Actinobacillus actinomycetemcomitans FDC Y4. Eikenella corrodens FDC 1073 and Capnocylophaga ochracea #M 12 were determined by enzyme-linked immunosorbent assay. The mean antibody titers to P. gingivalis and P. intermedia decreased significantly after the treatment as compared to their pretreatment levels. The antibody titer to P. gingivalis, especially, decreased in all of the patients examined. A significant relationship was found between the decreased antibody titer to P. gingivalis and the number of teeth which received periodontal surgery, as well as treatment length, and the relationship between the decreased antibody titer to P. intermedia and the number of extracted teeth was also significant. These results suggest that the changes of serum IgG titers against P. gingivalis and P. intermedia are related to the suppression of such pathogens in subgingival plaque.     

西帕依固龈液的抑菌作用和防治牙龈炎的临床效果评价

目的 观察西帕依固龈液体外抑制牙周可疑致病菌的作用和体内防治牙龈炎的临床疗效.方法 用琼脂稀释法测定西帕依固龈液对牙龈卟啉单胞菌、中间普雷沃菌和具核梭杆菌的最低抑菌浓度(MIC);将临床诊断为单纯性牙龈炎的50例患者随机分为实验组和对照组,基线检查后分别给予西帕依固龈液和不含有效成分基质的含漱液漱口,观察使用含漱液漱口7 d后两组受试者龈沟出血指数CSBI)和菌斑指数(PLI)的变化.结果 西帕依固龈液对牙龈卟啉单胞菌、具核梭杆菌的MIC是1.0g/L,对中间普雷沃菌的MIC是0.5 g/L:实验组用药前后的SBI和PLI差异有统计学意义,用药后两组的SBI和PLI差异有统计学意义.结论 西帕依固龈液对牙周可疑致病菌具有明显的抑制作用,可减少牙菌斑的堆积、降低SBI和改善牙龈健康.     

Transmission of periodontal disease-associated bacteria from teeth to osseointegrated implant regions

PURPOSE: The presence of periodontopathic bacteria is a risk factor for peri-implantitis. The present study examined colonization by periodontopathic bacteria and their transmission from periodontal pockets to osseointegrated implant sulcus. MATERIALS AND METHODS: Plaque samples were collected from 105 sites in the 15 patients who participated in the study. Colonization by these bacteria was examined by polymerase chain reaction (PCR) and culture. The transmission of periodontopathic bacteria from periodontal sites of natural teeth to the implant sulcus was analyzed by pulsed field gel electrophoresis (PFGE). RESULTS: The PCR detection rates of Porphyromonas gingivalis, Prevotella intermedia, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Treponema denticola were 80.0%, 53.3%, 46.7%, 60.0% and 40.0%, respectively. Colonizations by P gingivalis and A actinomycetemcomitans were statistically correlated with periodontal pockets and implant sulcus regions (P < .01). The PFGE patterns of the P gingivalis strains isolated from each patient were identical, but differed from those from other patients. The PFGE patterns of P intermedia strains were identical in 2 out of 3 patients. DISCUSSION: These analyses indicated that there appeared to be transmission of P gingivalis and P intermedia from the periodontal pocket to the peri-implant region. CONCLUSION: Elimination of these periodontal pathogens from the patient's oral cavity before administering dental implant treatment may inhibit colonization by these pathogens and reduce the risk of peri-implantitis.     

Microbiological profile of early onset/aggressive periodontitis patients

OBJECTIVES: The objectives of this study were to characterize the bacterial profile and to seek possible bacterial associations in the subgingival microbiota of early onset periodontitis/aggressive periodontitis patients by using two different techniques, culture and immunofluorescence. MATERIAL AND METHODS: The study group consisted of 66 systemically healthy individuals with evidence of early onset periodontitis - 41 females and 25 males aged 23-35 years (mean 31.1 +/- 3.1 years). Bacterial samples were collected from the deepest site in each quadrant, resulting in a total of 264 sites with a mean probing pocket depth of 6.6 +/- 1.5 mm. Samples were cultured anaerobically and in 10% CO(2) using selective and nonselective media, and isolates were characterized to species level. Indirect immunofluorescence using monoclonal antibodies was applied to detect Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia (Bacteroides forsythus, Tannerella forsythensis), Prevotella intermedia/Prevotella nigrescens, Campylobacter rectus, Peptostreptococcus micros and Actinomyces israelii. RESULTS: 93.6% of sampled sites showed bleeding on probing and 23.5% were positive for suppuration. P. intermedia/P. nigrescens, P. gingivalis, and C. rectus were detected in 77.3-85.9% of samples using culture methods and in 85.6-91.3% using immunofluorescence. P. micros and A. actinomycetemcomitans were found, respectively, in 63.3% and 25.0% of all sites using culturing and in 58.7% and 27.7% sites using immunofluorescence. Significantly strong positive associations were observed between T. forsythia and C. rectus (odds ratio 109.46), and T. forsythia and P. gingivalis (odd ratio 90.26), whereas a negative association was seen between P. intermedia/P. nigrescens and A. actinomycetemcomitans (odds ratio 0.42). Coinfection by P. gingivalis, T. forsythia, P. intermedia/P. nigrescens and C. rectus was observed in 62.1% of the test sites, and in 89.4% of the studied subjects. The sensitivity of immunofluorescence for T. forsythia, C. rectus, P. intermedia/P. nigrescens and P. gingivalis was found to be very high (0.99-0.94) using culture as the reference detection method. The agreement between culture and immunofluorescence in detecting the presence or absence of the investigated species was 85.2-88.1% for P. gingivalis, P. intermedia/P. nigrescens, C. rectus, and T. forsythia, 75.9% for A. actinomycetemcomitans and 70.4% for P. micros. CONCLUSIONS: The microbial profile of the early onset/aggressive periodontitis population was complex. The agreement between the two detection methods was very high.