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Lamont RJ, Miller DP, Bagaitkar J. Illuminating the oral microbiome: cellular microbiology. FEMS Microbiol Rev 2023; 47:fuad045. [PMID: 37533213 PMCID: PMC10657920 DOI: 10.1093/femsre/fuad045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 07/11/2023] [Accepted: 08/01/2023] [Indexed: 08/04/2023] Open
Abstract
Epithelial cells line mucosal surfaces such as in the gingival crevice and provide a barrier to the ingress of colonizing microorganisms. However, epithelial cells are more than a passive barrier to microbial intrusion, and rather constitute an interactive interface with colonizing organisms which senses the composition of the microbiome and communicates this information to the underlying cells of the innate immune system. Microorganisms, for their part, have devised means to manipulate host cell signal transduction pathways to favor their colonization and survival. Study of this field, which has become known as cellular microbiology, has revealed much about epithelial cell physiology, bacterial colonization and pathogenic strategies, and innate host responses.
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Affiliation(s)
- Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, KY, KY40202, United States
| | - Daniel P Miller
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, VA23298, United States
| | - Juhi Bagaitkar
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, OH43205, United States
- Department of Pediatrics, The Ohio State College of Medicine, Columbus, OH, OH43210, United States
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2
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Fouillen A, Mary C, Ponce KJ, Moffatt P, Nanci A. A proline rich protein from the gingival seal around teeth exhibits antimicrobial properties against Porphyromonas gingivalis. Sci Rep 2021; 11:2353. [PMID: 33504866 PMCID: PMC7840901 DOI: 10.1038/s41598-021-81791-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 01/08/2021] [Indexed: 12/22/2022] Open
Abstract
The gingival seal around teeth prevents bacteria from destroying the tooth-supporting tissues and disseminating throughout the body. Porphyromonas gingivalis, a major periodontopathogen, degrades components of the specialized extracellular matrix that mediates attachment of the gingiva to the tooth. Of these, secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1) protein has a distinctive resistance to degradation, suggesting that it may offer resistance to bacterial attack. In silico analysis of its amino acid sequence was used to explore its molecular characteristics and to predict its two- and three-dimensional structure. SCPPPQ1 exhibits similarities with both proline-rich and cationic antimicrobial proteins, suggesting a putative antimicrobial potential. A combination of imaging approaches showed that incubation with 20 μM of purified SCPPPQ1 decrease bacterial number (p < 0.01). Fluorescence intensity decreased by 70% following a 2 h incubation of Porphyromonas gingivalis with the protein. Electron microscopy analyses revealed that SCPPPQ1 induced bacterial membrane disruption and breaches. While SCPPPQ1 has no effect on mammalian cells, our results suggest that it is bactericidal to Porphyromonas gingivalis, and that this protein, normally present in the gingival seal, may be exploited to maintain a healthy seal and prevent systemic dissemination of bacteria.
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Affiliation(s)
- Aurélien Fouillen
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Charline Mary
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Katia Julissa Ponce
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Pierre Moffatt
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,Shriners Hospitals for Children - Canada, Montreal, QC, Canada
| | - Antonio Nanci
- Laboratory for the Study of Calcified Tissues and Biomaterials, Faculty of Dental Medicine, Université de Montréal, Montreal, QC, Canada. .,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada.
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3
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Krueger E, Brown AC. Aggregatibacter actinomycetemcomitans leukotoxin: From mechanism to targeted anti-toxin therapeutics. Mol Oral Microbiol 2020; 35:85-105. [PMID: 32061022 DOI: 10.1111/omi.12284] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 12/13/2022]
Abstract
Aggregatibacter actinomycetemcomitans is a Gram-negative bacterium associated with localized aggressive periodontitis, as well as other systemic diseases. This organism produces a number of virulence factors, all of which provide some advantage to the bacterium. Several studies have demonstrated that clinical isolates from diseased patients, particularly those of African descent, frequently belong to specific clones of A. actinomycetemcomitans that produce significantly higher amounts of a protein exotoxin belonging to the repeats-in-toxin (RTX) family, leukotoxin (LtxA), whereas isolates from healthy patients harbor minimally leukotoxic strains. This finding suggests that LtxA might play a key role in A. actinomycetemcomitans pathogenicity. Because of this correlation, much work over the past 30 years has been focused on understanding the mechanisms by which LtxA interacts with and kills host cells. In this article, we review those findings, highlight the remaining open questions, and demonstrate how knowledge of these mechanisms, particularly the toxin's interactions with lymphocyte function-associated antigen-1 (LFA-1) and cholesterol, enables the design of targeted anti-LtxA strategies to prevent/treat disease.
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Affiliation(s)
- Eric Krueger
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
| | - Angela C Brown
- Department of Chemical and Biomolecular Engineering, Lehigh University, Bethlehem, PA, USA
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4
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Fouillen A, Grenier D, Barbeau J, Baron C, Moffatt P, Nanci A. Selective bacterial degradation of the extracellular matrix attaching the gingiva to the tooth. Eur J Oral Sci 2019; 127:313-322. [PMID: 31230388 PMCID: PMC6771947 DOI: 10.1111/eos.12623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2019] [Indexed: 12/17/2022]
Abstract
The junctional epithelium (JE) is a specialized portion of the gingiva that seals off the tooth‐supporting tissues from the oral environment. This relationship is achieved via a unique adhesive extracellular matrix that is, in fact, a specialized basal lamina (sBL). Three unique proteins – amelotin (AMTN), odontogenic ameloblast‐associated (ODAM), and secretory calcium‐binding phosphoprotein proline‐glutamine rich 1 (SCPPPQ1) – together with laminin‐332 structure the supramolecular organization of this sBL and determine its adhesive capacity. Despite the constant challenge of the JE by the oral microbiome, little is known of the susceptibility of the sBL to bacterial degradation. Assays with trypsin‐like proteases, as well as incubation with Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola, revealed that all constituents, except SCPPPQ1, were rapidly degraded. Porphyromonas gingivalis was also shown to alter the supramolecular network of reconstituted and native sBLs. These results provide evidence that proteolytic enzymes and selected gram‐negative periodontopathogenic bacteria can attack this adhesive extracellular matrix, intimating that its degradation could contribute to progression of periodontal diseases.
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Affiliation(s)
- Aurélien Fouillen
- Laboratory for the Study of Calcified Tissues and Biomaterials, Université de Montréal, Montréal, QC, Canada.,Department of Stomatology, Faculty of Dental Medicine, Université de Montréal, Montréal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | - Daniel Grenier
- Oral Ecology Research Group, Faculty of Dentistry, Université Laval, Quebec City, QC, Canada
| | - Jean Barbeau
- Department of Stomatology, Faculty of Dental Medicine, Université de Montréal, Montréal, QC, Canada
| | - Christian Baron
- Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
| | | | - Antonio Nanci
- Laboratory for the Study of Calcified Tissues and Biomaterials, Université de Montréal, Montréal, QC, Canada.,Department of Stomatology, Faculty of Dental Medicine, Université de Montréal, Montréal, QC, Canada.,Department of Biochemistry and Molecular Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC, Canada
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Fawzy El-Sayed K, Graetz C, Köhnlein T, Mekhemar M, Dörfer C. Effect of total sonicated Aggregatibacter actinomycetemcomitans fragments on gingival stem/progenitor cells. Med Oral Patol Oral Cir Bucal 2018; 23:e569-e578. [PMID: 30148477 PMCID: PMC6167108 DOI: 10.4317/medoral.22661] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 08/16/2018] [Indexed: 01/24/2023] Open
Abstract
Background Aggregatibacter-actinomycetemcomitans (A.actinomycetemcomitans) are strongly associated with localized-aggressive-periodontitis (LAgP). The study’s aim was to test for the first time the effect of total sonicated A.actinomycetemcomitans-bacterial-fragments on gingival mesenchymal stem/progenitor cells’ (G-MSCs) proliferation and regenerative gene expression in-vitro. Material and Methods G-MSCs were isolated, characterized, expanded and stimulated by total sonicated A.actinomycetemcomitans-bacterial-fragments (0 (negative-control), 15, 60, 120 and 240µg/ml; serovar-b; n=6/group). Cellular proliferation and NF-κβ (NFKB1), Alkaline Phosphatase (ALPL), Collagen-I (COL1A1), Collagen-III (COL3A1), Osteonectin (SPARC) and Osteopontin (SPP1) m-RNA expression were assessed via reverse-transcription-polymerase-chain-reaction (RT-PCR) at 24, 48 and 72 hours and CFUs-ability evaluated at twelve days. Results G-MSCs demonstrated stem/progenitor cells’ characteristics. A.actinomycetemcomitans-bacterial-fragments (up to 72 hours) resulted in marked G-MSCs’ proliferation over-time (p<0.001) and elevated NFKB1 (p=0.017), COL1A1 (p=0.025), SPARC (p=0.025), decreased ALPL (p=0.017), with no significant differences for COL3A1 and SPP1 expression or stimulation times (p>0.05; Friedman-test). Longer-term stimulation for twelve days reduced G-MSCs’ CFUs. Conclusions Sonicated A.actinomycetemcomitans-bacterial-fragments’ exert beneficial short-term effects on G-MSCs’ proliferative and non-mineralized tissue forming aptitude. Results shed new light on the importance of periodontal treatment for LAgP patients, using power driven sonic/ultrasonic devices, which, in addition to reducing the subgingival microbial load, produces cell-stimulatory A.actinomycetemcomitans-bacterial-fragments, with positive attributes on tissue reparative/regenerative responses of tissue resident stem/progenitor cells in their niche. Key words:Ultrasonic, Aggregatibacter actinomycetemcomitans, stem cells, gingiva, Aggressive periodontitis.
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Affiliation(s)
- K Fawzy El-Sayed
- Clinic for Conservative Dentistry and Periodontology, School of Dental Medicine, Christian Albrechts-Universität zu Kiel, Arnold-Heller-Str. 3, Haus 26, 24105 Kiel, Germany,
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Kolakovic M, Held U, Schmidlin PR, Sahrmann P. An estimate of pocket closure and avoided needs of surgery after scaling and root planing with systemic antibiotics: a systematic review. BMC Oral Health 2014; 14:159. [PMID: 25529408 PMCID: PMC4531502 DOI: 10.1186/1472-6831-14-159] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 12/09/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Relevant benefits of adjunctive medication of antibiotica after conventional root surface debridement in terms of enhanced pocket depth (PD) reduction have been shown. However, means and standard deviations of enhanced reductions are difficult to translate into clinical relevant treatment outcomes such as pocket resolution or avoidance of additional surgical interventions. Accordingly, the aim of this systematic review was to calculate odds ratios for relevant cut-off values of PD after mechanical periodontal treatment with and without antibiotics, specifically the combination of amoxicilline and metronidazol, from published studies. As clinical relevant cut-off values "pocket closure" for PD ≤ 3mm and "avoidance of surgical intervention" for PD ≤ 5 mm were determined. METHODS The databases PubMed, Embase and Central were searched for randomized clinical studies assessing the beneficial effect of the combination of amoxicillin and metronidazole after non-surgical mechanical debridement. Titles, abstracts and finally full texts were scrutinized for possible inclusion by two independent investigators. Quality and heterogeneity of the studies were assessed and the study designs were examined. From published means and standard deviations for PD after therapy, odds ratios for the clinically relevant cut-off values were calculated using a specific statistical approach. RESULTS Meta-analyses were performed for the time points 3 and 6 month after mechanical therapy. Generally, a pronounced chance for pocket closure from 3 to 6 months of healing was shown. The administration of antibiotics resulted in a 3.55 and 4.43 fold higher probability of pocket closure after 3 and 6 months as compared to mechanical therapy alone. However, as the estimated risk for residual pockets > 5 mm was 0 for both groups, no odds ratio could be calculated for persistent needs for surgery. Generally, studies showed a moderate to high quality and large heterogeneity regarding treatment protocol, dose of antibiotic medication and maintenance. CONCLUSION With the performed statistical approach, a clear benefit in terms of an enhanced chance for pocket closure by co-administration of the combination of amoxicillin and metronidazole as an adjunct to non-surgical mechanical periodontal therapy has been shown. However, data calculation failed to show a benefit regarding the possible avoidance of surgical interventions.
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Affiliation(s)
- Mirela Kolakovic
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
| | - Ulrike Held
- Horten Center, University Hospital Zurich, Pestalozzistrasse 24, 8091, Zurich, Switzerland.
| | - Patrick R Schmidlin
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
| | - Philipp Sahrmann
- Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Plattenstrasse 11, 8032, Zurich, Switzerland.
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Feres M, Cortelli SC, Figueiredo LC, Haffajee AD, Socransky SS. Microbiological basis for periodontal therapy. J Appl Oral Sci 2012; 12:256-66. [PMID: 20976394 DOI: 10.1590/s1678-77572004000400002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2003] [Accepted: 09/23/2004] [Indexed: 11/21/2022] Open
Abstract
The search for the etiologic agents of periodontal diseases started in the Golden Era of medical bacteriology, when the etiologic agents of many bacterial infections were isolated and characterized. After the initial enthusiasm in establishing the infectious nature and the true agents of periodontal diseases, this concept was virtually ignored for the next four decades. Until the early 1970s treatment regimens based on the non-specific plaque hypothesis were directed towards a non-specific reduction in plaque amount. Later, the specific plaque hypothesis established the role of some microorganisms such as A. actinomycetemcomitans, P. gingivalis, T. forsythensis, T. denticola, P. intermedia and F. nucleatum in different forms of periodontal diseases. It was recently suggested that these suspected periodontal pathogens seem to not act alone and interactions between species, especially the balance between pathogenic and beneficial species affect both progression of disease and response of tissues to periodontal therapy. Nowadays it is well established that one of the goals of therapy is to control such periodontal pathogens. Among the most commonly used therapies to treat periodontal infections are scaling and root planing (SRP), supragingival plaque control and periodontal surgeries. Many studies confirmed the reduction of "red complex" species by SRP, and apically repositioned flap can lead to an additional beneficial effect in the subgingival microbiota by decreasing levels of "red" and "orange complexes" species. Furthermore, the level of plaque control maintained by the patients has been considered a crucial step in preventing recurrence of destructive periodontitis.
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Affiliation(s)
- Magda Feres
- Dental Research Division, Department of Periodontology, Guarulhos University, SP, Brasil
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8
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Beliveau D, Magnusson I, Bidwell JA, Zapert EF, Aukhil I, Wallet SM, Shaddox LM. Benefits of early systemic antibiotics in localized aggressive periodontitis: a retrospective study. J Clin Periodontol 2012; 39:1075-81. [PMID: 22931240 DOI: 10.1111/jcpe.12001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2012] [Indexed: 01/16/2023]
Abstract
BACKGROUND Treatment of localized aggressive periodontitis (LAP) may include systemic antibiotics, yet it is unclear at what stage of treatment planning antibiotics are most effective. AIM This retrospective analysis compared immediate versus delayed antibiotic therapy on clinical parameters and gingival crevicular fluid (GCF) inflammatory mediators. MATERIAL AND METHODS At baseline, 3 months and 6 months after treatment, clinical parameters [probing depth (PD), clinical attachment level (CAL), bleeding on probing (BoP) and plaque] and GCF were collected from LAP participants, who received a 7-day antibiotic regimen immediately (ImA) or 3 months following (DelA) mechanical therapy. RESULTS Although both groups presented significant CAL reductions at 6 months, only ImA resulted in a reduction in mean PD at both 3 and 6 months, along with reductions in CAL and BoP at 3 months following therapy. In addition, GCF mediators were higher in DelA group at 3 months post mechanical treatment, but were significantly reduced 6 months following antibiotic therapy. CONCLUSIONS ImA and DelA regimens were both effective in improving CAL by 6 months post therapy. However, ImA allowed for better improvement in overall clinical parameters early in the course of treatment, concomitant with lower levels of inflammatory mediators within the GCF.
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Kang P, Korostoff J, Volgina A, Grzesik W, DiRienzo JM. Differential effect of the cytolethal distending toxin of Actinobacillus actinomycetemcomitans on co-cultures of human oral cells. J Med Microbiol 2005; 54:785-794. [PMID: 16014433 PMCID: PMC1434796 DOI: 10.1099/jmm.0.46077-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The periodontal pathogen Actinobacillus actinomycetemcomitans expresses a cytolethal distending toxin (CDT) that typically arrests the growth of eukaryotic cells at either the G0/G1 or G2/M phase of the cell cycle. It was previously found that CDT failed to arrest the growth of human periodontal ligament fibroblasts (HPLFs) when grown in pure culture. In contrast, proliferation of an oral epithelial cell line was rapidly inhibited by the toxin. In this study, the feasibility of using mixed-cell cultures and cell-specific markers to evaluate the response of oral cells, when in heterogeneous populations, to CDT was established. Proliferation of epithelial cells was rapidly inhibited and the cells were selectively eliminated in co-culture with HPLFs or cementoblasts by 24-48 h post-intoxication. Epithelial cells and HPLFs were detected and counted in co-cultures following cell-specific immunolabelling with antibodies against simian virus 40 large T antigen and the Ab-1 surface antigen, respectively. These results demonstrated that the activities of potential virulence factors, such as CDT, from periodontal pathogens can be successfully examined in mixed-cell cultures. This approach is especially relevant to infectious diseases that affect tissues with a diverse cellular composition, such as the periodontium.
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Affiliation(s)
- Philip Kang
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA
| | - Jonathan Korostoff
- Department of Periodontics, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA
| | - Alla Volgina
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA
| | - Wojciech Grzesik
- Department of Anatomy & Cell Biology, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA
| | - Joseph M. DiRienzo
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA
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10
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Umeda M, Takeuchi Y, Noguchi K, Huang Y, Koshy G, Ishikawa I. Effects of nonsurgical periodontal therapy on the microbiota. Periodontol 2000 2004; 36:98-120. [PMID: 15330945 DOI: 10.1111/j.1600-0757.2004.03675.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Makoto Umeda
- Department of Hard Tissue Engineering, Tokyo Medical and Dental University Graduate School, JapanDepartment of Hard Tissue Engineering, Tokyo Medical and Dental University Graduate School, Japan
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11
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Eick S, Pfister W. Efficacy of Antibiotics Against Periodontopathogenic Bacteria Within Epithelial Cells: An In Vitro Study. J Periodontol 2004; 75:1327-34. [PMID: 15562909 DOI: 10.1902/jop.2004.75.10.1327] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Periodontopathogenic bacteria can invade and survive within epithelial cells, but susceptibility of intracellular infection to antibiotics used in periodontitis treatment has not been studied to date. METHODS KB cells were infected by Actinobacillus actinomycetemcomitans, strain NCTC 9710; Porphyromonas gingivalis, strains ATCC 33277 and JH16-1; or Streptococcus constellatus, strain J012b. After 2, 4, and 12 hours the bactericidal effect of antibiotics (clindamycin, doxycycline, metronidazole, and moxifloxacin) on intracellular microorganisms was tested at a concentration up to the 100-fold minimum inhibitory concentration (MIC) determined separately on planktonic bacteria. RESULTS The P. gingivalis strains differed in their invasiveness and ATCC 33277 was 100-fold more invasive than JH16-1. Doxycycline and clindamycin at a concentration 10-fold MIC had no effect, but P. gingivalis intercellular infection was significantly reduced by metronidazole at 10-fold MIC after 2 and 4 hours. Moxifloxacin was effective, but a 100-fold MIC concentration was necessary to reduce P. gingivalis strains intracellular growth to 7% of the control. Other bacterial species grown inside the KB cells were more susceptible to antibiotics. Clindamycin at 10-fold MIC reduced the number of intracellular S. constellatus after 4 and 12 hours. This bacterium was eliminated by moxifloxacin at 50-fold MIC. Intracellular A. actinomycetemcomitans was killed by 10-fold MIC of doxycycline and moxifloxacin after 4 hours incubation. CONCLUSIONS Moxifloxacin was the most efficient antibiotic to treat intracellular infection. However, taking into account the MIC values and the levels of antibiotics in gingival fluid, elimination of intracellular bacteria by antibiotics alone seems to be questionable.
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Affiliation(s)
- Sigrun Eick
- Department of Oral Microbiology, Institute of Medical Microbiology, University Hospital of Jena, Jena, Germany.
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12
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Henderson B, Nair SP, Ward JM, Wilson M. Molecular pathogenicity of the oral opportunistic pathogen Actinobacillus actinomycetemcomitans. Annu Rev Microbiol 2004; 57:29-55. [PMID: 14527274 DOI: 10.1146/annurev.micro.57.030502.090908] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Periodontitis is mankind's most common chronic inflammatory disease. One severe form of periodontitis is localized aggressive periodontitis (LAP), a condition to which individuals of African origin demonstrate an increased susceptibility. The main causative organism of this disease is Actinobacillus actinomycetemcomitans. A member of the Pasteurellaceae, A. actinomycetemcomitans produces a number of interesting putative virulence factors including (a) an RTX leukotoxin that targets only neutrophils and monocytes and whose action is influenced by a novel type IV secretion system involved in bacterial adhesion; (b) the newly discovered toxin, cytolethal distending toxin (CDT); and (c) a secreted chaperonin 60 with potent leukocyte-activating and bone resorbing activities. This organism also produces a plethora of proteins able to inhibit eukaryotic cell cycle progression and proteins and peptides that can induce distinct forms of proinflammatory cytokine networks. A range of other proteins interacting with the host is currently being uncovered. In addition to these secreted factors, A. actinomycetemcomitans is invasive with an unusual mechanism for entering, and traveling within, eukaryotic cells. This review focuses on recent advances in our understanding of the molecular and cellular pathogenicity of this fascinating oral bacterium.
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Affiliation(s)
- Brian Henderson
- Cellular Microbiology Research Group, Eastman Dental Institute, University College London, London WC1X 8LD, United Kingdom.
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13
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Quirynen M, Teughels W, van Steenberghe D. Microbial shifts after subgingival debridement and formation of bacterial resistance when combined with local or systemic antimicrobials. Oral Dis 2003; 9 Suppl 1:30-7. [PMID: 12974528 DOI: 10.1034/j.1601-0825.9.s1.6.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antibiotics have played a major role in the improvement of life expectancy in the last 50 years and have led many to believe that bacterial infections were about to vanish as a disease entity of any importance. Emerging problems resulting from a widespread use of antibiotics have modified the general perception of the capabilities of antimicrobial agents. Over the years, bacteria have become increasingly resistant to formerly potent antimicrobial agents, including some antiseptics. The use of antimicrobials may also disturb the delicate ecological equilibrium of the body, allowing the proliferation of resistant bacteria or non-bacterial micro-organisms. This shift may initiate new infections that are worse than the ones originally treated. No antimicrobial drug is absolutely non-toxic and the use of an agent carries accompanying risks. This paper discusses the development and occurrence of antimicrobial resistance in the subgingival flora towards antiseptics and local or systemic antibiotics and is focussed on the question: how can the outcome of periodontal therapy with/without antimicrobials be improved?
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Affiliation(s)
- M Quirynen
- Catholic University of Leuven, Faculty of Medicine, Research Group for Microbial Adhesion, Department of Periodontology, School of Dentistry, Oral Pathology & Maxillo-facial Surgery, Leuven, Belgium.
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Abstract
Aggressive periodontitis is characterized by a considerable attachment loss over a relatively short period of time. It may be the consequence of either the presence of highly aggressive pathogens or a highly susceptible host. In the first case, the use of antimicrobials should be beneficial in the treatment of those patients. However, due to the organization of the micro-organisms as a biofilm, the increasing incidence of allergies and resistance against antimicrobials and their side-effects, there is still controversy about their benefit in the treatment of periodontal disease. This paper discusses indications for the use of antimicrobials, the substances prescribed and the type of application under the conditions of aggressive periodontitis.
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Affiliation(s)
- C E Dörfer
- Department Conservative Dentistry and Periodontology, University of Heidelberg, Heidelberg, Germany.
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15
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Affiliation(s)
- Paul J Ezzo
- Department of Biomedical Sciences, Baylor College of Dentistry, Texas A&M University System Health Science Center Dallas, Texas, USA
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17
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DiRienzo JM, Song M, Wan LSY, Ellen RP. Kinetics of KB and HEp-2 cell responses to an invasive, cytolethal distending toxin-producing strain of Actinobacillus actinomycetemcomitans. ORAL MICROBIOLOGY AND IMMUNOLOGY 2002; 17:245-51. [PMID: 12121475 PMCID: PMC1434795 DOI: 10.1034/j.1399-302x.2002.170407.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The periodontal pathogen Actinobacillus actinomycetemcomitans produces cytolethal distending toxin (CDT), a complex multicomponent toxin that arrests the growth of many types of eukaryotic cell. The kinetics of the effects of CDT-containing extracts, from an invasive strain of this bacterium, were examined on epithelial-like cells routinely used in invasion studies. Both KB and HEp-2 cells were exquisitely sensitive to the effects of the CDT with TD50 of 30 and 300 pg of total bacterial protein, respectively. Initial cell morphology changes were relatively rapid, occurring within the first 13 h of exposure. CDT-treated KB cells increased in size to 4-5 times the size of untreated controls. Cytotoxicity was irreversible when attached cells were incubated, for a minimum of 120 min, with nanogram quantities of CDT-containing extract. As cultures aged, the cells became more resistant to the effects of the CDT-containing extracts. These findings have important implications for understanding the ability of A. actinomycetemcomitans to invade and multiply in epithelial cells.
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Affiliation(s)
- J M DiRienzo
- Department of Microbiology, School of Dental Medicine, University of Pennsylvania, 4010 Locust Street, Philadelphia, PA 19104-6002, USA
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Quirynen M, Teughels W, De Soete M, van Steenberghe D. Topical antiseptics and antibiotics in the initial therapy of chronic adult periodontitis: microbiological aspects. Periodontol 2000 2002; 28:72-90. [PMID: 12013349 DOI: 10.1034/j.1600-0757.2002.280104.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Marc Quirynen
- Department of Periodontology, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Catholic University Leuven, Belgium
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19
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Affiliation(s)
- C J Dickinson
- Wolfson Institute of Preventive Medicine, St. Bartholomew's and the Royal London School of Medicine and Dentistry, London, UK.
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20
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Abstract
Some periodontal pathogens disrupt epithelial barriers and cellular adhesion to the extracellular matrix, which affects the cytoskeleton. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans exploit the cytoskeleton during their uptake by epithelial cells. Treponema denticola perturbs actin and actin-regulating pathways in host cells. Cytoskeletal dysfunction due to pathogenic bacteria may impair physiologic remodeling and wound repair in the periodontium.
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Affiliation(s)
- R P Ellen
- University of Toronto, Faculty of Dentistry, 124 Edward Street, Toronto M5G 1G6, Canada
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21
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Socransky SS, Haffajee AD, Ximenez-Fyvie LA, Feres M, Mager D. Ecological considerations in the treatment of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis periodontal infections. Periodontol 2000 1999; 20:341-62. [PMID: 10522230 DOI: 10.1111/j.1600-0757.1999.tb00165.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S S Socransky
- Department of Periodontology, Forsyth Dental Center, Boston, Massachusetts, USA
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22
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Fives-Taylor PM, Meyer DH, Mintz KP, Brissette C. Virulence factors of Actinobacillus actinomycetemcomitans. Periodontol 2000 1999; 20:136-67. [PMID: 10522226 DOI: 10.1111/j.1600-0757.1999.tb00161.x] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A. actinomycetemcomitans has clearly adapted well to its environs; its armamentarium of virulence factors (Table 2) ensures its survival in the oral cavity and enables it to promote disease. Factors that promote A. actinomycetemcomitans colonization and persistence in the oral cavity include adhesins, bacteriocins, invasins and antibiotic resistance. It can interact with and adhere to all components of the oral cavity (the tooth surface, other oral bacteria, epithelial cells or the extracellular matrix). The adherence is mediated by a number of distinct adhesins that are elements of the cell surface (outer membrane proteins, vesicles, fimbriae or amorphous material). A. actinomycetemcomitans enhances its chance of colonization by producing actinobacillin, an antibiotic that is active against both streptococci and Actinomyces, primary colonizers of the tooth surface. The fact that A. actinomycetemcomitans resistance to tetracyclines, a drug often used in the treatment of periodontal disease, is on the rise is an added weapon. Periodontal pathogens or their pathogenic products must be able to pass through the epithelial cell barrier in order to reach and cause destruction to underlying tissues (the gingiva, cementum, periodontal ligament and alveolar bone). A. actinomycetemcomitans is able to elicit its own uptake into epithelial cells and its spread to adjacent cells by usurping normal epithelial cell function. A. actinomycetemcomitans may utilize these remarkable mechanisms for host cell infection and migration to deeper tissues. A. actinomycetemcomitans also orchestrates its own survival by elaborating factors that interfere with the host's defense system (such as factors that kill phagocytes and impair lymphocyte activity, inhibit phagocytosis and phagocyte chemotaxis or interfere with antibody production). Once the organisms are firmly established in the gingiva, the host responds to the bacterial onslaught, especially to the bacterial lipopolysaccharide, by a marked and continual inflammatory response, which results in the destruction of the periodontal tissues. A. actinomycetemcomitans has at least three individual factors that cause bone resorption (lipopolysaccharide, proteolysis-sensitive factor and GroEL), as well as a number of activities (collagenase, fibroblast cytotoxin, etc.) that elicit detrimental effects on connective tissue and the extracellular matrix. It is of considerable interest to know that A. actinomycetemcomitans possesses so many virulence factors but unfortunate that only a few have been extensively studied. If we hope to understand and eradicate this pathogen, it is critical that in-depth investigations into the biochemistry, genetic expression, regulation and mechanisms of action of these factors be initiated.
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Affiliation(s)
- P M Fives-Taylor
- Department of Microbiology & Molecular Genetics, University of Vermont, Burlington, USA
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Abstract
Oral bacteria exhibit highly specific adherence mechanisms and as a result they colonize and cause disease principally in the oral cavity. Oral pathogens, however, can produce systemic disease and are known causative agents of infective endocarditis. Recent studies have revealed that periodontal disease per se is also a statistically significant risk factor for cardiovascular disease. A link between the two diseases is the secretion and systemic appearance in periodontitis of pro-inflammatory cytokines capable of eliciting effects associated with atherosclerosis and coronary heart disease.
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Affiliation(s)
- D H Meyer
- Department of Microbiology and Molecular Genetics, Stafford Hall, University of Vermont, Burlington, VT 05405, USA.
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Hillmann G, Dogan S, Geurtsen W. Histopathological investigation of gingival tissue from patients with rapidly progressive periodontitis. J Periodontol 1998; 69:195-208. [PMID: 9526920 DOI: 10.1902/jop.1998.69.2.195] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this study, fine structural features of the pocket walls in rapidly progressive periodontitis (RPP) and adult periodontitis (AP) in 20 cases were compared using light and transmission electron microscopy. Gingiva was also obtained from a control group of periodontally healthy teeth. Clinical parameters were assessed in both RPP and AP patients and in controls. Bone destruction and attachment loss were more marked in RPP than in AP. Light microscopical observations of inflamed RPP tissue as compared to AP showed gross histological distortions in the pocket walls. Micro-ridges within the epithelium and large intercellular spaces between the epithelial cells were observed in most RPP biopsies. Epithelial cells surrounding the microclefts and adjacent keratinocytes were found to produce interleukin-1beta (IL-1beta). Prevotella intermedia and Porphyromonas gingivalis were identified in the RPP biopsies using immunohistological methods. These microorganisms were localized outside the epithelium and inside intercellular spaces. Furthermore, the effect of inflammation on the distribution of collagen types I, III, IV, V, and VI in the human gingiva was studied after staining them with antibodies to these proteins. In RPP and AP tissues, the staining was sparse in areas of inflammation and leukocytic infiltration. Collagen type I and III were almost entirely lost at sites of inflammation. Type V and VI collagen antibodies were retained in inflamed areas. Type IV collagen was restricted to basement membrane structures. These observations demonstrated numerous structural features indicative of more pronounced degenerative changes in RPP than in AP.
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Affiliation(s)
- G Hillmann
- Department of Conservative Dentistry and Periodontology, Dental School, Medical University of Hannover, Germany
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Meyer DH, Mintz KP, Fives-Taylor PM. Models of invasion of enteric and periodontal pathogens into epithelial cells: a comparative analysis. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1997; 8:389-409. [PMID: 9391752 DOI: 10.1177/10454411970080040301] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bacterial invasion of epithelial cells is associated with the initiation of infection by many bacteria. To carry out this action, bacteria have developed remarkable processes and mechanisms that co-opt host cell function and stimulate their own uptake and adaptation to the environment of the host cell. Two general types of invasion processes have been observed. In one type, the pathogens (e.g., Salmonella and Yersinia spp.) remain in the vacuole in which they are internalized and replicate within the vacuole. In the other type, the organism (e.g., Actinobacillus actinomycetemcomitans, Shigella flexneri, and Listeria monocytogenes) is able to escape from the vacuole, replicate in the host cell cytoplasm, and spread to adjacent host cells. The much-studied enteropathogenic bacteria usurp primarily host cell microfilaments for entry. Those organisms which can escape from the vacuole do so by means of hemolytic factors and C type phospholipases. The cell-to-cell spread of these organisms is mediated by microfilaments. The investigation of invasion by periodontopathogens is in its infancy in comparison with that of the enteric pathogens. However, studies to date on two invasive periodontopathogens. A actinomycetemcomitans and Porphyromonas (Bacteroides) gingivalis, reveal that these bacteria have developed invasion strategies and mechanisms similar to those of the enteropathogens. Entry of A. actinomycetemcomitans is mediated by microfilaments, whereas entry of P. gingivalis is mediated by both microfilaments and microtubules. A. actinomycetemcomitans, like Shigella and Listeria, can escape from the vacuole and spread to adjacent cells. However, the spread of A. actinomycetemcomitans is linked to host cell microtubules, not microfilaments. The paradigms presented establish that bacteria which cause chronic infections, such as periodontitis, and bacteria which cause acute diseases, such as dysentery, have developed similar invasion strategies.
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Affiliation(s)
- D H Meyer
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington 05405, USA
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Affiliation(s)
- J J Zambon
- Department of Periodontology, State University of New York, School of Dental Medicine, Buffalo, USA
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Sandros J, Madianos PN, Papapanou PN. Cellular events concurrent with Porphyromonas gingivalis invasion of oral epithelium in vitro. Eur J Oral Sci 1996; 104:363-71. [PMID: 8930584 DOI: 10.1111/j.1600-0722.1996.tb00093.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The aim of the present study was to elucidate events related to receptor function, signal transmission and cytoskeletal rearrangements concurrent with Porphyromonas gingivalis invasion of oral epithelial cells in vitro. Porphyromonas gingivalis strain FDC 381 and the KB cell line (ATCC CCL 17) were used in a previously described antibiotic protection assay. The involvement of a receptor-mediated endocytosis pathway in the internalization process was demonstrated after treatment of the epithelial cells with monodansylcadaverine and ouabain, substances that inhibit formation of coated pits, resulting in reduction in the number of invading P. gingivalis: Treatment of the epithelial cells with the protein kinase (PK) inhibitor staurosporine and the tyrosine-specific PK inhibitor genistein was also found to significantly decrease the number of invading bacteria, suggesting involvement of tyrosine phosphorylation in signal transduction during invasion. This was further supported by the identification of a 43 kD protein acting as a substrate for tyrosine phosphorylation subsequent to the microbial-host cell interaction. Tyrosine phosphorylation of the 43 kD protein was strongly reduced by treatment with PK inhibitors. The decrease in invasion observed after treatment of epithelial cells with colchicine and nocodazole, inhibitors of microtubuli polymerization, suggested that the bacterial-receptor interaction and the phosphotyrosine-dependent intracellular signalling trigger an internalization process involving rearrangements of cytoskeletal microtubuli.
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Affiliation(s)
- J Sandros
- Department of Oral Microbiology, Faculty of Odontology, Göteborg University, Sweden.
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28
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Affiliation(s)
- T E Rams
- Division of Dental Medicine & Surgery, Medical College of Pennsylvania, Philadelphia, USA
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Loimaranta V, Söderling E, Peltonen E, Törmäläi P. Interactions of Periodontal Pathogens and Biofix®, a Self-reinforced Polyglycolide Membrane. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 1996. [DOI: 10.3109/08910609609167728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- V. Loimaranta
- Institute of Dentistry, University of Turku, Turku, Finland
| | - E. Söderling
- Institute of Dentistry, University of Turku, Turku, Finland
| | - E. Peltonen
- Institute of Dentistry, University of Turku, Turku, Finland
| | - P. Törmäläi
- Institute of Plastic Technology, Tampere University of Technology, Tampere, Finland
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Wilson M, Henderson B. Virulence factors of Actinobacillus actinomycetemcomitans relevant to the pathogenesis of inflammatory periodontal diseases. FEMS Microbiol Rev 1995; 17:365-79. [PMID: 8845187 DOI: 10.1111/j.1574-6976.1995.tb00220.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
There is strong evidence implicating Actinobacillus actinomycetemcomitans as the causative agent of localised juvenile periodontitis (LJP), a disease characterised by rapid destruction of the tooth-supporting tissues. This organism possesses a large number of virulence factors with a wide range of activities which enable it to colonise the oral cavity, invade periodontal tissues, evade host defences, initiate connective tissue destruction and interfere with tissue repair. Adhesion to epithelial and tooth surfaces is dependent on the presence of surface proteins and structures such as microvesicles and fimbriae. Invasion has been demonstrated in vivo and in vitro although the mechanisms involved are poorly understood. The organism has a number of means of evading host defences which include: (i) inhibiting poloymorphonuclear leukocyte (PMN) chemotaxis; (ii) killing PMNs and monocytes; (iii) producing immunosuppressive factors; (iv) secreting proteases capable of cleaving IgG; and (v) producing Fc-binding proteins. Surface components of A. actinomycetemcomitans are potent stimulators of bone resorption and can induce the release of a range of cytokines which can initiate tissue destruction. A number of surface components can also inhibit the proliferation of fibroblasts and their production of components of the extracellular matrix. Little is known, however, regarding the way in which these factors operate in vivo to produce the pathological features of the disease.
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Affiliation(s)
- M Wilson
- Department of Microbiology Eastman Dental Institute for Oral Health Care Sciences, University of London, UK
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31
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Lamont RJ, Chan A, Belton CM, Izutsu KT, Vasel D, Weinberg A. Porphyromonas gingivalis invasion of gingival epithelial cells. Infect Immun 1995; 63:3878-85. [PMID: 7558295 PMCID: PMC173546 DOI: 10.1128/iai.63.10.3878-3885.1995] [Citation(s) in RCA: 432] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Porphyromonas gingivalis, a periodontal pathogen, can invade primary cultures of gingival epithelial cells. Optimal invasion occurred at a relatively low multiplicity of infection (i.e., 100) and demonstrated saturation at a higher multiplicity of infection. Following the lag phase, during which bacteria invaded poorly, invasion was independent of growth phase. P. gingivalis was capable of replicating within the epithelial cells. Invasion was an active process requiring both bacterial and epithelial cell energy production. Invasion was sensitive to inhibitors of microfilaments and microtubules, demonstrating that epithelial cell cytoskeletal rearrangements are involved in bacterial entry. P. gingivalis, but not epithelial cell, protein synthesis was necessary for invasion. Invasion within the epithelial cells was not blocked by inhibitors of protein kinase activity. Invasion was inhibited by protease inhibitors, suggesting that P. gingivalis proteases may be involved in the invasion process. Low-passage clinical isolates of P. gingivalis invaded with higher efficiency than the type strain. Serum inhibited invasion of the type strain but had no effect on the invasion of a clinical isolate. Invasion of gingival epithelial cells by P. gingivalis may contribute to the pathology of periodontal diseases.
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Affiliation(s)
- R J Lamont
- Department of Oral Biology, School of Dentistry, University of Washington, Seattle 98195, USA
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32
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Preus HR, Russell DT. Use of a nonradioactive genetic probe identified, synthesized, and labeled in the polymerase chain reaction. SCANDINAVIAN JOURNAL OF DENTAL RESEARCH 1994; 102:161-7. [PMID: 7521967 DOI: 10.1111/j.1600-0722.1994.tb01173.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This study introduces a strategy to identify and produce sequences useful as genetic markers, or native genetic probes for DNA-DNA hybridization in bacterial strains where the genetics is not well described. Actinobacillus actinomy-cetemcomitans (A.a.) was used as an example. Fifty ng genomic DNA from A.a. ATCC 33384 and Haemophilus aphrophilus ATCC 33389 was amplified in a thermocycler using a single 10-mer primer. The PCR products were separated by electrophoresis on a 1% submarine agarose gel containing ethidium bromide and visualized by UV illumination, and the strain-specific amplitypes were compared. DNA from two bands, 0.9 and 4 kb, unique for the A.a. strain, was cut out, amplified under high stringency with the same primer and labeled by replacing 33.3 microM dTTP with digoxigenin-labeled dUTP in the reaction mixture. The labeled probe was then repeatedly used for hybridization to DNA from various A.a., H. aphrophilus, and other bacterial strains of the Pasteurellaceae family. The results showed that the 0.9-kb probe detected all A.a. tested, and distinguished it from other closely related bacterial species. We conclude that the described strategy is useful for identifying and selecting genetic sequences useful as genetic markers in A.a.
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Affiliation(s)
- H R Preus
- Department of Periodontology, Dental Faculty, University of Oslo, Norway
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33
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Affiliation(s)
- A D Haffajee
- Department of Periodontology, Forsyth Dental Center, Boston, Massachusetts, USA
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34
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Affiliation(s)
- J M Goodson
- Department of Pharmacology, Forsyth Dental Center, Boston, Massachusetts, USA
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Sandros J, Papapanou PN, Nannmark U, Dahlén G. Porphyromonas gingivalis invades human pocket epithelium in vitro. J Periodontal Res 1994; 29:62-9. [PMID: 8113953 DOI: 10.1111/j.1600-0765.1994.tb01092.x] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The present study examined the adhesive and invasive potential of Porphyromonas gingivalis interacting with human pocket epithelium in vitro. Pocket epithelial tissue, obtained during periodontal surgery of patients with advanced periodontal disease, generated a stratified epithelium in culture. P. gingivalis strains W50 and FDC 381 (laboratory strains), OMGS 712, 1439, 1738, 1739 and 1743 (clinical isolates) as well as Escherichia coli strain HB101 (non-adhering control) were tested with respect to epithelial adhesion and invasion. Adhesion was quantitated by scintillation spectrometry after incubation of radiolabeled bacteria with epithelial cells. The invasive ability of P. gingivalis was measured by means of an antibiotic protection assay. The epithelial multilayers were infected with the test and control strains and subsequently incubated with an antibiotic mixture (metronidazole 0.1 mg/ml and gentamicin 0.5 mg/ml). The number of internalized bacteria surviving the antibiotic treatment was assessed after plating lyzed epithelial cells on culture media. All tested P. gingivalis strains adhered to and entered pocket epithelial cells. However, considerable variation in their adhesive and invasive potential was observed. E. coli strain HB101 did not adhere or invade. Transmission electron microscopy revealed that internalization of P. gingivalis was preceded by formation of microvilli and coated pits on the epithelial cell surfaces. Intracellular bacteria were most frequently surrounded by endosomal membranes; however, bacteria devoid of such membranes were also seen. Release of outer membrane vesicles (blebs) by internalized P. gingivalis was observed. These results support and extend previous work from this laboratory which demonstrated invasion of a human oral epithelial cell-line (KB) by P. gingivalis.
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Affiliation(s)
- J Sandros
- Department of Periodontology, Faculties of Odontology, University of Gothenburg, Sweden
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Abstract
While the efficacy of oral irrigations with antimicrobial agents on the clinical and microbial parameters of gingivitis is well established, the study of the efficacy of intrapocket irrigants on periodontitis has yielded conflicting and inconclusive results regarding both clinical and microbiological parameters. The overall goal of this review paper is to summarize the available information on the efficacy of intrapocket irrigation in the treatment of patients with periodontitis. The following topics are addressed: 1) the penetrability of the irrigant; 2) pocket irrigation without scaling and root planing; 3) professional pocket irrigation following scaling and root planing; 4) irrigations between recalls; and 5) safety of intrapocket irrigation. Single irrigation of periodontal pockets for short periods of time before or after scaling and root planing has limited effects on periodontal healing. However, continuous irrigation of the periodontal lesion with agents such as povidone iodine during thorough scaling and root planing, such as that carried out under local anesthesia, has promise as an antimicrobial adjunct in periodontal therapy.
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Affiliation(s)
- J Shiloah
- Department of Periodontology, University of Tennessee, College of Dentistry, Memphis
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