Improved, low-cost selective culture medium for Actinobacillus actinomycetemcomitans

Mode of killing determines the necrotrophic response of oral bacteria

Background

Bacteria respond to changes in their environment, such as nutrient depletion and antimicrobials exposure. Antimicrobials result not only in bacterial death, but also have a hand in determining species abundances and ecology of the oral biofilms. Proximity of dead bacterial cells to living ones is an important environmental change or stress factor. Dead bacteria represent high concentrations of nutrients, such as proteins, lipids, sugars, and nucleic acids. Living bacteria can use these biomasses as a nutrients source, which is termed necrotrophy.

Aim

This study investigates the effect of exposing living oral bacteria (planktonic and biofilms) to their dead siblings after being killed by heat or hydrogen peroxide.

Results

Tested bacterial species showed different responses towards the dead cells, depending on the mode of killing, the nutritional value of the culture media, and the the dead cells density. The multispecies oral biofilms showed different responses towards the supplementation of dead cells during biofilm development, while matured biofilms were more resilient.

Conclusion

This study indicates that dead bacteria resulting from antiseptics use may imbalance the nutrient availability in the oral cavity, resulting in overgrowth of opportunistic species, and hence ecological changes in oral communities, or introducing new bacterial phenotypes.

Clinical, Microbiological, and Biochemical Impact of the Surgical Treatment of Peri-Implantitis-A Prospective Case Series

Background: The aim of this study, a prospective case series, was to evaluate the clinical, microbiological, and biochemical impact of the surgical treatment of peri-implantitis. Methods: Thirty subjects with diagnosis of peri-implantitis were treated following a surgical protocol including access flaps, surface decontamination with ultrasonics and glycine powder air-polishing, and systemic antibiotics. Disease resolution was defined by the composite outcome including presence of probing depths (PD) ≤5 mm, absence of bleeding on probing (BoP)/suppuration, and no additional radiographic bone loss (>1 mm). Regression analysis was used to evaluate the patient-, implant-, and prosthetic-related factors possibly influencing treatment outcomes. Results: Patients were evaluated at 6 months post treatment, demonstrating statistically significant reductions in PD (2.14 ± 1.07 mm) and increase in mucosal recession (1.0 ± 0.77 mm). Plaque, BoP, and suppuration were also reduced by 40.56%, 62.22%, and 7.78%, respectively. Disease resolution was achieved in 56.67% of patients. No significant changes were detected in microbiological parameters except for a significant reduction in proportions of Parvimonas micra. Similarly, the levels of the biomarker interleukin-8 in crevicular fluid were significantly lower at 6 months. Conclusions: The proposed surgical treatment of peri-implantitis demonstrated statistically significant clinical improvements although the impact on microbiological and biochemical parameters was scarce.

The subgingival cultivable bacteria of Albanian subjects with different periodontal status compared to a similar population of Spanish subjects: a case control study

Background

The objective was to qualitatively and quantitatively describe the subgingival cultivable bacteria in Albanian subjects and to compare it with a similar Spanish population.

Materials and methods

Consecutive patients, diagnosed as periodontitis in stages I–II or III–IV, and as periodontally healthy or with gingivitis, were studied clinically and microbiologically by means of microbiological culture, including total anaerobic counts, proportions, and frequency of detection of target species. Outcome variables were analysed by Mann–Whitney, Kruskal–Wallis, ANOVA, ANCOVA and Chi-square tests.

Results

In this cross-sectional study, 83 (Albania) and 90 (Spain) subjects were included. No statistically significant differences were observed between test and control populations regarding demographic variables or smoking habit. Significantly higher total anaerobic counts in the Albanian population (p = 0.022) were observed, especially in the periodontal health/gingivitis group (p = 0.001). In the test population, the proportions of the cultivable bacteria of Fusobacterium nucleatum were significantly lower in both the healthy/gingivitis (p = 0.022) and stages I–II periodontitis (p = 0.034) groups.

Conclusions

The subgingival cultivable bacteria in both periodontitis and non-periodontitis subjects from Albania showed significantly higher total anaerobic counts and lower proportions of the cultivable bacteria of F. nucleatum than a similar population of subjects from Spain.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02121-5.

In Vitro Antibacterial Activity of Myrtus communis L. and Marrubium vulgare L. Leaves against Aggregatibacter actinomycetemcomitans and Eikenella corrodens

Materials and Methods

Clinical strains of Aggregatibacter actinomycetemcomitans and Eikenella corrodens and two reference strains of A. actinomycetemcomitans were tested. The antibacterial activity of each studied plant extract was evaluated using agar diffusion and broth microdilution assays.

Results

Both aqueous and methanolic extracts of M. communis exhibited high antibacterial activity against periodontal pathogens as compared to M. vulgare extracts. At concentrations of 2.5-0.32 mg/disc, inhibition zones of the methanolic extract of M. communis ranged from 19.66 ± 0.57 to 12.33 ± 0.57 mm. The methanolic extract of M. vulgare showed at concentrations of 5-0.63 mg/disc inhibition zones ranging from 15.66 ± 0.57 to 12 ± 0.00 mm. Its aqueous extract at concentration of 0.63 mg/disc showed no antimicrobial activity against the clinical and reference strain of A. actinomycetemcomitans. Conclusion. This study showed that methanolic and aqueous extracts of M. communis and M. vulgare have in vitro an antibacterial activity against periodontal pathogens. They could be use as ingredients of an oral antimicrobial agent for prevention or treatment of periodontal diseases. Further research on isolating the compounds from these plant extracts and their toxicity effect could be conducted.

Characterization of the Subgingival Cultivable Microbiota in Patients with Different Stages of Periodontitis in Spain and Colombia. A Cross-Sectional Study

The objective was to characterize and compare the subgingival microbiota in patients diagnosed according to the World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions 2018. For this cross-sectional study, Spanish and Colombian subjects (characterized as health/gingivitis, periodontitis in stages I-II or stages III-IV) were clinically assessed, and subgingival samples were taken and processed by culture. The comparisons among patients with periodontal status (and between countries) was made using Mann–Whitney, Kruskal–Wallis, ANOVA and chi-square tests. The final sample consisted of 167 subjects. Eikenella corrodens and Parvimonas micra were more frequently detected in health/gingivitis and Porphyromonas gingivalis in periodontitis (p < 0.05). Higher total counts were observed in Colombia (p = 0.036). In Spain, significantly higher levels of P. gingivalis and Campylobacter rectus were observed, and of Tannerella forsythia, P. micra, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus and Capnocytophaga spp. in Colombia (p < 0.001). P. micra was more prevalent in health/gingivitis and stage I-II periodontitis in Colombia, and P. gingivalis in all periodontitis groups in Spain (p < 0.05). As conclusions, significant differences were detected in the microbiota between health/gingivitis and periodontitis, with minor differences between stages of periodontitis. Differences were also relevant between countries, with Colombia showing larger counts and variability of bacterial species.

Quantification of pathogenic bacteria in the subgingival oral biofilm samples collected from cigarette-smokers, individuals using electronic nicotine delivery systems and non-smokers with and without periodontitis

OBJECTIVE

The aim of the present study was to quantify pathogenic bacteria isolated from the subgingival oral-biofilm samples collected from cigarette-smokers and ENDS-users with periodontitis, when compared to non-smokers with and without periodontitis.

METHODS

Demographic data was collected using a questionnaire. Periodontal parameters (plaque [PI] and gingival [GI] indices, clinical attachment loss [CAL], probing depth [PD] and marginal bone loss [MBL]) were measured. Subgingival oral bio-film samples were collected and assessed for periodontopathogenic bacteria (Aggregatibacter actinomycetemcomitans [A. actinomycetemcomitans], Prevotella intermedia [P. intermedia], Porphyromonas gingivalis [P. gingivalis], Tannerella forsythia [T. forsythia] and Treponema denticola [T. denticola]). Group-comparisons were performed; and P < 0.01 were considered statistically significant.

RESULTS

All cigarette-smokers, ENDS-users and non-smokers with periodontitis had Grade-B periodontitis. The CFU/mL of A. actinomycetemcomitans (P < 0.001) and P. gingivalis (P < 0.001) were significantly higher among cigarette-smokers (P < 0.01) and ENDS-users (P < 0.01) than non-smokers with periodontitis. The CFU/mL of T. denticola were significantly higher among cigarette-smokers (P < 0.001), ENDS-users (P < 0.001) and non-smokers with periodontitis (P < 0.001) compared with non-smokers without periodontitis. There was no statistically significant difference in the CFU/mL of P. intermedia and T. denticola among cigarette-smokers, ENDS-users and non-smokers with periodontitis.

CONCLUSION

Counts of periodontopathogenic bacteria in the subgingival oral-biofilm are comparable among cigarette-smokers and individuals using ENDS.

Antimicrobial resistance of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia in periodontitis patients

OBJECTIVES

Administration of systemic antimicrobials as an adjunct to mechanical treatment of periodontitis and sites with adverse clinical results leads to improved outcomes. This study aimed to assess the antimicrobial susceptibility of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia isolated from periodontitis patients to amoxicillin, metronidazole, azithromycin and moxifloxacin.

METHODS

A total of 76 patients diagnosed with generalised periodontitis were included in the study. Subgingival samples were processed by culture. Etest was used to determine susceptibility to amoxicillin, metronidazole, azithromycin and moxifloxacin.

RESULTS

A total of 141 isolates from 76 patients were evaluated, including 61 P. gingivalis, 43 T. forsythia and 37 A. actinomycetemcomitans. Etest results showed complete susceptibility of A. actinomycetemcomitans, P. gingivalis and T. forsythia to moxifloxacin. However, the isolates presented reduced susceptibility to the other antimicrobial agents investigated. Of the A. actinomycetemcomitans isolates, 70.3%, 40.5% and 89.2% were resistant to amoxicillin, azithromycin and metronidazole, respectively. The P. gingivalis samples showed relatively similar rates of resistance to amoxicillin (24.6%), azithromycin (21.3%) and metronidazole (24.6%). Similarly, 25.6%, 21.0% and 25.6% of the T. forsythia isolates were resistant to amoxicillin, azithromycin, and metronidazole, respectively.

CONCLUSION

These findings show that moxifloxacin may be a promising antimicrobial agent against P. gingivalis, T. forsythia and A. actinomycetemcomitans for the treatment of periodontitis. However, amoxicillin, azithromycin and metronidazole were less effective, especially against A. actinomycetemcomitans in vitro.

Chemical Composition, Antimicrobial activity, in Vitro Cytotoxicity and Leukotoxin Neutralization of Essential Oil from Origanum vulgare against Aggregatibacter actinomycetemcomitans

In this study, the essential oil of Origanum vulgare was evaluated for putative antibacterial activity against six clinical strains and five reference strains of Aggregatibacter actinomycetemcomitans, in comparison with some antimicrobials. The chemical composition of the essential oil was analyzed, using chromatography (CG) and gas chromatography-mass spectrometry coupled (CG-MS). The major compounds in the oil were Carvacrol (32.36%), α-terpineol (16.70%), p-cymene (16.24%), and Thymol (12.05%). The antimicrobial activity was determined by an agar well diffusion test. A broth microdilution method was used to study the minimal inhibitory concentration (MIC). The minimal bactericidal concentration (MBC) was also determined. The cytotoxicity of the essential oil (IC50) was <125 µg/mL for THP-1 cells, which was high in comparison with different MIC values for the A. actinomycetemcomitans strains. O. vulgare essential oil did not interfere with the neutralizing capacity of Psidium guajava against the A. actinomycetemcomitans leukotoxin. In addition, it was shown that the O. vulgare EO had an antibacterial effect against A. actinomycetemcomitans on a similar level as some tested antimicrobials. In view of these findings, we suggest that O.vulgare EO may be used as an adjuvant for prevention and treatment of periodontal diseases associated to A. actinomycetemcomitans. In addition, it can be used together with the previously tested leukotoxin neutralizing Psidium guajava.

Clinical effects of the adjunctive use of a 0.03% chlorhexidine and 0.05% cetylpyridinium chloride mouth rinse in the management of peri-implant diseases: A randomized clinical trial

AIM

To evaluate the efficacy of a 0.03% chlorhexidine and 0.05% cetylpyridinium chloride mouth rinse, as an adjunct to professionally and patient-administered mechanical plaque removal, in the treatment of peri-implant mucositis (PiM).

MATERIAL AND METHODS

Patients displaying PiM in, at least, one implant were included in this randomized, double-blinded, clinical trial. Subjects received professional prophylaxis (baseline and 6 months) and were instructed to regular oral hygiene practices and to rinse, twice daily, with the test or placebo mouth rinses, during one year. Clinical, radiographic and microbiological outcomes were evaluated at baseline, 6 and 12 months. Disease resolution was defined as absence of bleeding on probing (BOP). Data were analysed by repeated measures ANOVA, Student's t and chi-square tests.

RESULTS

Fifty-four patients were included and 46 attended the final visit (22 in control and 24 in test group). In the test group, there was a 24.49% greater reduction in BOP at the buccal sites (95% confidence interval [3.65-45.34%]; p = 0.002) than in controls. About 58.3% of test implants and 50% controls showed healthy peri-implant tissues at final visit (p > 0.05).

CONCLUSIONS

The use of the test mouth rinse demonstrated some adjunctive benefits in the treatment of PiM. Complete disease resolution could not be achieved in every case.

Non-Surgical Treatment of Periodontal Disease in a Pregnant Caucasian Women Population: Adverse Pregnancy Outcomes of a Randomized Clinical Trial

Aim: To analyze if non-surgical treatment of periodontitis in a pregnant Caucasian women population can reduce adverse pregnancy outcomes. Methods and results: A parallel randomized clinical trial was designed and approved by the Ethical Committee of Sanitary Area Santiago-Lugo, Spain (registration number: 2016/451). Forty patients with periodontitis stage II grade B were randomly allocated to receive either comprehensive non-surgical periodontal therapy (test group; n = 20) or professional tooth cleaning (control group; n = 20) before 24 gestational weeks. Randomization was computer-generated by the statistic program Epidat v.4.1 and allocation was performed using sealed opaque envelopes. Clinical measurements and peripheral blood samples for biochemical variables were collected at baseline, in the middle of second trimester before non-surgical treatment, and in the third trimester. Microbiological samples were collected in the second and third trimester. A statistically significant reduction was verified in all clinical and microbiological parameters after periodontal treatment in the test group. No significant differences were observed for the rest of the variables, including preterm birth and/or low birth weight. No adverse events related to periodontal treatment were reported. Conclusions: Non-surgical periodontal treatment in Caucasian patients with periodontitis stage II grade B did not significantly reduce the risk of adverse pregnancy outcomes.

Clinical and microbiological effects of the use of a cetylpyridinium chloride dentifrice and mouth rinse in orthodontic patients: a 3-month randomized clinical trial

Objective

To assess the clinical, microbiological, and patient-based effects of using a cetylpyridinium chloride (CPC) toothpaste and mouth rinse in orthodontic patients.

Design

Parallel randomized controlled, triple-blinded trial (participants, examiners, outcomes' assessors). A computer-generated list was used to allocate treatments. Central allocation was used for concealment.

Participants

Thirty-one placebo (10 males, 21 females; mean age 15.2 ± 2.1) and 32 test patients (15 males, 17 females; mean age 15.0 ± 1.8) with fixed orthodontic appliance were included in the study.

Interventions

Patients were randomly assigned to both brush and rinse with placebo or with CPC-based products. Products were purposely prepared in white opaque bottles. After screening and professional prophylaxis, patients received a baseline examination, and started to use the assigned products. Patients were monthly assessed during a 3-month period.

Main outcome measures

Plaque (PlI) and gingival (GI) indexes. Secondary outcome variables: Calculus index, tooth staining, subgingival microbiological samples, patient-based variables (questionnaire, compliance, and remaining mouth rinse), side-effects (debonded braces or mucosal injuries).

Results

Sixty-three patients were randomized, 13 patients were excluded from analysis because of early dropout, leaving 50 patients for intention to treat analysis. PlI in the upper jaw diminished (0.18; SD = 0.82) after 1 month in the test group, while it increased (0.26; SD = 0.62) in the placebo group (P = 0.024). Statistically significant higher GI values were observed in the placebo group at 1 month (mean increase = 0.05; SD = 0.33 versus mean decrease = 0.03; SD = 0.38) and 3 months (mean = 0.05; SD = 0.43 versus mean = 0.02; SD = 0.34). The taste of the test product was rated higher than the placebo at 2- and 3-month visits (P < 0.05). Non-significant changes were observed in microbiological parameters, overgrowth of opportunistic species or remaining secondary outcome variables, including side-effects.

Conclusion

The use of CPC-based toothpaste and mouth rinse in orthodontic patients had limited effect in reducing plaque accumulation and gingival inflammation. Effects were little and highly variable. The use of the test products was not associated with relevant adverse effects.

Trial registration

Trial registration: Local internal reference: P07/133.

Antimicrobial susceptibility pattern of oral isolates of Aggregatibacter actinomycetemcomitans

Background:

Aggregatibacter actinomycetemcomitans is involved in the etiology of localized aggressive periodontitis (LAP), a condition that frequently requires supplemental antibiotic therapy. Information on antimicrobial susceptibility pattern and guidelines for oral antibiotic therapy are not available on Indian patients.

Aim:

The main aim of the present study was to screen clinical isolates on a panel of antibiotics commonly used for oral/systemic therapy.

Materials and Methods:

The study included 40 strains of A. actinomycetemcomitans isolated from patients with LAP. The subgingival plaque was plated onto Trypticase Soy Serum Bacitracin Vancomycin Agar medium and incubated for 72 h, and suspected colonies were confirmed by phenotypic tests. Each isolate was tested against a panel of 12 antibiotics using MIC gradient strip test. ATCC strains of A. actinomycetemcomitans serotype A and C were used as standards. Performance and interpretation of the test were done according to the manufacturers’ instructions. Distribution of MICs among isolates (n = 40) were used to calculate concentrations inhibiting 50% (MIC₅₀) and 90% (MIC₉₀) of strains.

Results:

Moxifloxacin, cefotaxime and ceftriaxone showed excellent activity with 100% growth inhibition followed by amoxicillin, amoxiclav and doxycycline (>90% activity). The bacterial strains were moderately susceptible to cefuroxime, cefazolin and tetracycline but displayed poor susceptibility to clindamycin and azithromycin. All isolates were resistant to metronidazole.

Conclusion:

The isolates of A. actinomycetemcomitans displayed a high level of resistance to azithromycin and clindamycin. Development of resistance against tetracycline also appears to be significant. Variable resistance among the different members of the cephalosporin group is a factor to be investigated further since susceptibility profile against these antibiotics and interpretative criteria for oral bacteria are not available.

Impact of photodynamic therapy versus ultrasonic scaler on gingival health during treatment with orthodontic fixed appliances

OBJECTIVES

Poor oral hygiene during treatment with fixed appliances results in plaque accumulation. The presence of bacteria in the gingival crevice triggers an inflammatory reaction in the gingival tissues. The aim of this study was to compare the impact of two preventive treatments, photodynamic therapy (PDT), and ultrasonic scaler (US), on gingival health in patients under fixed orthodontic treatment.

METHODS

Twenty orthodontic patients were randomly allocated to two groups: PDT or US. Each group received seven sessions [days 0, 15, 30, 45, 90 (3-months follow-up), 180 (6-months follow-up), 270 (9-months follow-up)] of experimental interventions, and clinical parameters [Plaque index(PI); gingival index(GI); probing depth(PD)], periodontopathogens [Agreggatibacter actinomycetemcomitans; Porphyromonas gingivalis; Prevotella intermedia; Micromonas micros; Fusobacterium nucleatum; Tannerella forsythia; Campylobacter rectus; Eikenella corrodens; Capnocytopaga sp.] and protein markers [IL-1β;IL-1ra;IL-6;IL-10;TNF-α;FGF-2/FGF basic] were monitored at baseline and at 3, 6, and 9 months. ANOVA, Student's t-test with Bonferroni correction and ANOVA with multiple rank test were used to identify differences between groups (P < 0.05).

RESULTS

Clinical assessments [PI, GI, and PD] yielded no differences (P > 0.05) between groups, which showed a major decrease at the start of the trial. Reductions in total colony forming units (log CFU reduction) were observed with both treatments, although to a greater extent in the PDT group, but with no differences between groups (P > 0.05). Similar reductions in log CFU counts of P. gingivalis, P. intermedia, and F. nucleatum were observed in both groups (P > 0.05). The two groups also showed similar trends for inflammatory mediators with decreased levels of IL-1β, IL-10, and TNF-α, whereas IL-6 and IL-1ra levels remained stable and those of FGF-2 were increased after both interventions, with no differences (P > 0.05) between groups.

CONCLUSION

Both PDT and US methods proved similar effectiveness for the treatment of gingival inflammation induced by fixed orthodontic appliances. Lasers Surg. Med. 51:256-267, 2019. © 2018 Wiley Periodicals, Inc.

Detection and quantification of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in bacteremia induced by interdental brushing in periodontally healthy and periodontitis patients

OBJECTIVE

This study was aimed to compare the presence and amounts of bacteremia induced by interdental brushing in periodontally healthy (H) and periodontitis (P) individuals using culture based (direct culture [DC]) and molecular based techniques (real-time quantitative polymerase chain reaction [qPCR]) in a cross-sectional study model.

MATERIALS AND METHODS

After a full mouth periodontal evaluation, blood samples were taken before and 1 min after professionally-administered interdental brushing. These samples were analyzed by DC and qPCR, targeting Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Subgingival samples were also collected and analyzed. Student t-test, chi-squar tests and correlations were used for analyzing the data.

RESULTS

Thirty individuals per group were included. P. gingivalis and A. actinomycetemcomitans were detected with qPCR methods, but not with DC. At baseline, bacteremia was observed in 5 P patients (16.7%) and in 2 H individuals (6.6%) (p = 0.421). After interdental brushing, bacteremia was only observed in 2 P patients (6.6%) (p = 0.901). A positive correlation between subgingival and blood levels of A. actinomycetemcomitans was observed (r = 0.3; p = 0.013).

CONCLUSION

Bacteremia related to A. actinomycetemcomitans and P. gingivalis did not significantly increase after a single session of use of interdental brushes.

Efficacy of photodynamic therapy vs ultrasonic scaler for preventing gingival inflammation and white spot lesions during orthodontic treatment

INTRODUCTION

The complex designs of fixed orthodontic appliances hinder proper access for cleaning, favouring the development of gingival inflammation and white spot lesions around brackets. The aim of this study was to evaluate the effectiveness to avoid these undesirable effects by using two prophylactic methods: Photodynamic Therapy (PDT) and conventional ultrasonic scaler (US), in patients during fixed orthodontic treatment.

MATERIALS AND METHODS

Twenty patients under orthodontic treatment for at least 15 months were randomly divided into two groups: PDT mediated by methylene blue (MB) and US. Both treatments were applied in repeated doses (four times in intervals of 2 weeks in the beginning of the study (T0), with booster doses at 3, 6 and 9 months, T1, T2 and T3, respectively). Periodontal clinical parameters (full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS) and probing depth (PD)) were recorded as well as the International Caries Detection and Assessment System (ICDAS) index. Samples of subgingival plaque and saliva (for determination of 4 periodontopathogens and mutans streptococci, respectively), were collected at T0 and at the follow-ups of T1, T2 and T3.

RESULTS

The evolution of FMPS, FMBS, PD, ICDAS scores as well as the counts of periodontopathogens and salivary mutans streptococci was similar after US or PDT implementation. Greatest periodontal scores reduction took place at T1 for FMBS and PD and at T2 for FMPS. Main microbial reduction took place at T1. ICDAS index began to increase from T2. No statistically significant intergroup differences were observed.

CONCLUSIONS

Additional treatment of PDT or US in repeated doses delayed undesired side effects during fixed orthodontic treatment in young patients with low caries risk and signs of gingival inflammation.

Antimicrobial susceptibilities of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis strains from periodontitis patients in Morocco

BACKGROUND AND OBJECTIVE

Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis have been frequently isolated in periodontitis patients in Morocco. Its persistence after the subgingival debridement of the biofilm has been correlated with worse clinical outcomes. The aim of this study was to evaluate the antimicrobial susceptibilities of A. actinomycetemcomitans and P. gingivalis, to amoxicillin, amoxicillin plus clavulanate, metronidazole, and azithromycin. In addition, microbiological profiles of patients harbouring A. actinomycetemcomitans, P. gingivalis, or both were compared.

MATERIAL AND METHODS

In 45 consecutive periodontitis Moroccan patients, subgingival samples were taken and processed by culture. Twenty-four A. actinomycetemcomitans and 30 P. gingivalis colonies were isolated (54 strains) and susceptibility tests, using the epsilometric method, were run for amoxicillin, amoxicillin plus clavulanate, metronidazole, and azithromycin. Minimum inhibitory concentrations for 50 (MIC50) and 90% (MIC90) of the organisms were calculated.

RESULTS

The prevalence of A. actinomycetemcomitans and P. gingivalis was 79.5 and 84.4%, respectively. A. actinomycetemcomitans showed susceptibility to amoxicillin, amoxicillin plus clavulanate, while 28% of the isolated strains were resistant to azithromycin and 61.7% towards metronidazole. No P. gingivalis resistance towards amoxicillin, amoxicillin plus clavulanate, metronidazole, and azithromycin was found.

CONCLUSION

A. actinomycetemcomitans and P. gingivalis were frequently detected in Moroccan patients with periodontitis, while antimicrobial resistance was only detected for A. actinomycetemcomitans to metronidazole and azithromycin.

CLINICAL RELEVANCE

A. actinomycetemcomitans resistance against some antimicrobials in periodontitis patients in Morocco can influence the selection of the therapeutic approaches.

NADPH Oxidase Contributes to Resistance against Aggregatibacter actinomycetemcomitans-Induced Periodontitis in Mice

Aggregatibacter actinomycetemcomitans is a Gram-negative commensal bacterium of the oral cavity which has been associated with the pathogenesis of periodontitis with severe alveolar bone destruction. The role of host factors such as reactive oxygen and nitrogen intermediates in periodontal A. actinomycetemcomitans infection and progression to periodontitis is still ill-defined. Therefore, this study aimed to analyze the role of NADPH oxidase and inducible nitric oxide synthase (iNOS) in a murine model of A. actinomycetemcomitans-induced periodontitis. NADPH oxidase-deficient (gp91^phox knockout [KO]), iNOS-deficient (iNOS KO), and C57BL/6 wild-type mice were orally infected with A. actinomycetemcomitans and analyzed for bacterial colonization at various time points. Alveolar bone mineral density and alveolar bone volume were quantified by three-dimensional micro-computed tomography, and the degree of tissue inflammation was calculated by histological analyses. At 5 weeks after infection, A. actinomycetemcomitans persisted at significantly higher levels in the murine oral cavities of infected gp91^phox KO mice than in those of iNOS KO and C57BL/6 mice. Concomitantly, alveolar bone mineral density was significantly lower in all three infected groups than in uninfected controls, but with the highest loss of bone density in infected gp91^phox KO mice. Only infected gp91^phox KO mice revealed significant loss of alveolar bone volume and enhanced inflammatory cell infiltration, as well as an increased number of osteoclasts. Our results indicate that NADPH oxidase is important to control A. actinomycetemcomitans infection in the murine oral cavity and to prevent subsequent alveolar bone destruction and osteoclastogenesis.

Evaluation of new chlorhexidine- and cetylpyridinium chloride-based mouthrinse formulations adjunctive to scaling and root planing: pilot study

OBJECTIVE

To compare the effect of two newly formulated chlorhexidine (CHX) and cetylpyridinium chloride (CPC) mouthrinses after scaling and root planing (SRP) in terms of clinical, microbiological, patient-based variables and adverse events, with a positive control with the same active components, already marketed and tested.

METHODS

A pilot, randomized clinical trial, double-blind, parallel design with 1-month follow-up was conducted. Chronic periodontitis patients requiring non-surgical periodontal therapy were enrolled and randomly assigned to: (i) SRP and test-1 (new reformulation: 0.12% CHX and 0.05% CPC); (ii) SRP and test-2 (new formulation: 0.03% CHX and 0.05% CPC); or (iii) SRP and positive control (commercial product: 0.12% CHX and 0.05% CPC). All variables were evaluated at baseline and 1 month after SRP. Quantitative variables were compared by means of anova or Kruskal-Wallis test and qualitative variables by chi-square or McNemar tests.

RESULTS

Thirty patients (10 per group) were included. After 1 month, there were significant differences among groups in plaque levels (P = 0.016) as test-1 showed less sites with plaque than test-2 (31.15% [standard error-SE 2.21%] versus 49.39% [SE 4.60%), respectively). No significant differences were found for global patient perception of the product or in adverse effects. Test groups showed better results in levels and proportions (P = 0.022) of Capnocytophaga spp.

CONCLUSIONS

Within the limitations of this pilot study, it can be concluded that the newly formulated 0.12% CHX and 0.05% CPC mouthrinse showed larger plaque level reductions, without showing more adverse effects, when compared to the other two mouthrinses, after SRP.

A Cytolethal Distending Toxin Variant from Aggregatibacter actinomycetemcomitans with an Aberrant CdtB That Lacks the Conserved Catalytic Histidine 160

The periodontopathogen Aggregatibacter actinomycetemcomitans synthesizes several virulence factors, including cytolethal distending toxin (CDT). The active CDT holoenzyme is an AB-type tripartite genotoxin that affects eukaryotic cells. Subunits CdtA and CdtC (B-components) allow binding and intracellular translocation of the active CdtB (A-component), which elicits nuclear DNA damage. Different strains of A. actinomycetemcomitans have diverse virulence genotypes, which results in varied pathogenic potential and disease progression. Here, we identified an A. actinomycetemcomitans strain isolated from two patients with advance chronic periodontitis that has a regular cdtABC operon, which, however, codes for a unique, shorter, variant of the CdtB subunit. We describe the characteristics of this CdtBΔ116–188, which lacks the intact nuclear localisation signal and the catalytic histidine 160. We show that the A. actinomycetemcomitans DO15 isolate secretes CdtBΔ116–188, and that this subunit cannot form a holotoxin and is also not genotoxic if expressed ectopically in HeLa cells. Furthermore, the A. actinomycetemcomitans DO15 isolate is not toxic, nor does it induce cellular distention upon infection of co-cultivated HeLa cells. Biological significance of this deletion in the cdtB remains to be explained.

Occurrence of Aggregatibacter actinomycetemcomitans in Indian chronic periodontitis patients and periodontally healthy adults

Background:

Aggregatibacter actinomycetemcomitans (Aa), an important primary periodontal pathogen, is known for its strong virulence characteristics that cause periodontal disease. We investigated Aa occurrence in Indian individuals using culture and 16 s rDNA polymerase chain reaction (PCR).

Materials and Methods:

A cross-sectional study with 100 participants each in the healthy and chronic periodontitis (CP) groups was conducted. The subgingival plaque was collected and immediately plated on selective media for Aa. The remaining plaque samples were used for DNA extraction. PCR was performed using specific primers for Aa.

Statistical Analysis Used:

The detection of bacteria and the clinical parameters between the groups were compared using the Mann–Whitney U-test. For assessing the agreement between the results of anaerobic culture and PCR, Kappa analyses were performed.

Results:

Aa levels using culture and PCR was 51% and 69% in the CP group and 12% and 30% in the healthy group, respectively. The two groups showed significant differences (P < 0.00001). The detection accuracy of culture and PCR was assessed, and the coefficient of accuracy (k) was highly significant in the healthy (0.3103; P < 0.0001) and CP groups (0.1536; P < 0.0497).

Conclusions:

Aa was predominantly found in the CP group compared with the healthy group, which is consistent with previous findings. Our results showed that both techniques can be used for detecting Aa. An ideal technique for detecting subgingival microorganisms should be carefully selected depending on the scope of the intended future work.

Comparison of the detection of periodontal pathogens in bacteraemia after tooth brushing by culture and molecular techniques

Background

The prevalence and amounts of periodontal pathogens detected in bacteraemia samples after tooth brushing-induced by means of four diagnostic technique, three based on culture and one in a molecular-based technique, have been compared in this study.

Material and Methods

Blood samples were collected from thirty-six subjects with different periodontal status (17 were healthy, 10 with gingivitis and 9 with periodontitis) at baseline and 2 minutes after tooth brushing. Each sample was analyzed by three culture-based methods [direct anaerobic culturing (DAC), hemo-culture (BACTEC), and lysis-centrifugation (LC)] and one molecular-based technique [quantitative polymerase chain reaction (qPCR)]. With culture any bacterial isolate was detected and quantified, while with qPCR only Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were detected and quantified. Descriptive analyses, ANOVA and Chi-squared tests, were performed.

Results

Neither BACTEC nor qPCR detected any type of bacteria in the blood samples. Only LC (2.7%) and DAC (8.3%) detected bacteraemia, although not in the same patients. Fusobacterium nucleatum was the most frequently detected bacterial species.

Conclusions

The disparity in the results when the same samples were analyzed with four different microbiological detection methods highlights the need for a proper validation of the methodology to detect periodontal pathogens in bacteraemia samples, mainly when the presence of periodontal pathogens in blood samples after tooth brushing was very seldom.

Key words:Bacteraemia, periodontitis, culture, PCR, tooth brushing.

Microbiological effects and recolonization patterns after adjunctive subgingival debridement with Er:YAG laser

OBJECTIVES

The objective of this study was to assess the microbiological effects and recolonization patterns after non-surgical periodontal treatment protocol based on the adjunctive use of erbium-doped yttrium aluminium garnet (Er:YAG) laser.

MATERIAL AND METHODS

Patients diagnosed with chronic periodontitis were randomly assigned to two different treatment protocols: test, full-mouth subgingival ultrasonic instrumentation followed by Er-YAG laser application 1 week later to sites with initial probing pocket depth ≥4.5 mm; and control, full-mouth ultrasonic subgingival instrumentation within 1 week. Clinical (at sampled sites) and microbiological (culture-based) parameters were recorded at baseline and 3 and 12 months. Microbiological variables included total counts, frequency of detection, proportions and counts of target species.

RESULTS

Results from 19 test and 21 control patients were compared. Minor changes were observed for total colony-forming units, with no differences between groups. For the frequency of detection, a limited and similar impact in both groups was observed for the most prevalent (over 80 %) periodontal pathogens (Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum). For proportions, reductions in P. gingivalis occurred at 3 months, both in the test and control groups (from 16.3 to 10 % and 16 to 14.8 %, respectively), although these differences were not statistically significant. At 12 months, the test group showed a statistically significant greater reduction in probing depth for the sampled sites.

CONCLUSIONS

The adjunctive use of Er:YAG laser when compared with conventional ultrasonic debridement did not provide a microbiological added benefit.

CLINICAL RELEVANCE

Even though some clinical benefits with the adjunctive laser application were identified when comparing both treatment protocols, there were no differences in microbiological outcomes or in the bacterial recolonization patterns.

Bacterial profile of aggressive periodontitis in Morocco: a cross-sectional study

Background

Aggressive periodontitis (AgP) is one of the most severe forms of periodontal diseases. In Morocco, Aggregatibacter actinomycetemcomitans has been strongly associated with AgP, however limited knowledge is available about the implication of other periodontal pathogens in this entity. Therefore, the main aim of this study was to evaluate the composition of the subgingival microbiota in Moroccan patients with AgP.

Methods

Subgingival plaque samples were collected from 50 aggressive, 13 localized and 37 generalized periodontitis patients. Samples from 20 chronic periodontitis (ChP) patients were taken as controls. Samples collected from the four deepest periodontal pockets in each patient were pooled in pre-reduced transport fluid and examined by culture.

Results

A. actinomycetemcomitans was significantly more frequent (p = 0.004) in generalised AgP compared to ChP, and Porphyromonas gingivalis was less prevalent in localized AgP, when compared with generalized AgP (p = 0.040) or ChP (p = 0.016). Prevotella intermedia, Fusobacterium nucleatum and Tannerella forsythia were also frequently detected in all groups. Mean proportions of A. actinomycetemcomitans were significantly higher in AgP groups, when compared to ChP, and generalized AgP patients harbored significantly higher proportions of P. gingivalis and T. forsythia, when compared to localized AgP or ChP.

Conclusions

A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia and F. nucleatum were frequently detected in this Moroccan population with AgP. Differences in frequency of detection, counts and proportions of A. actinomycetemcomitans, P. gingivalis and T. forsythia suggests the presence of distinct microbiological profiles for localized AgP, generalized AgP and ChP patients.

Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans isolated from a population of periodontitis patients in Spain

OBJECTIVE

There is no study characterizing the variability of Aggregatibacter actinomycetemcomitans isolates in periodontitis patients in Spain. It is therefore the aim of this investigation to study the serotype distribution of A. actinomycetemcomitans strains isolated from periodontitis patients in Spain. The polymorphism of the genes that codifies the leukotoxin and the operon of the cytolethal-distending toxin (cdt) will also be investigated.

DESIGN

From a total of 701 patients samples, 40 A. actinomycetemcomitans-positive periodontitis patients were included in the study (mean age 45.3, 62.5% females) and their clinical periodontal status was assessed. On average, 1-3 isolates from each patient were sub-cultured and characterized by PCR.

RESULTS

Using culture the prevalence of A. actinomycetemcomitans was 5.7%. The most frequent serotype was "b", being 30 patients infected by a unique serotype, while 7 patients showed co-colonization, mostly with serotypes "a" and "b". From the 79 pure isolates obtained, 24 were from serotype "a", 30 from serotype "b", 12 from serotype "c" and 4 from serotype "d". Further characterization of these samples showed that none of these 79 isolates demonstrated the 530-bp deletion in the leukotoxin's promoter region that characterizes the JP2 strain. Conversely 65.8% of the isolates were cdt+.

CONCLUSIONS

The most common serotypes were "a" and "b", being serotype "b" the most prevalent in mono-colonization, while serotypes "e" and "f" were not detected. In the majority of samples, operon that codifies the cdt (65.8%) and the genes responsible for the codification of leukotoxin (100%) were found. None of the isolates were JP2 strains.

Isolation and identification of Porphyromonas spp. and other putative pathogens from cats with periodontal disease

The purpose of this study was to evaluate the subgingival microbiota and determine the most prevalent periodontal pathogens implicated in feline periodontal disease and to correlate these findings with the clinical periodontal status. Subgingival microbiological samples were taken under sedation from 50 cats with clinical signs of periodontal disease. Pooled paper point samples from 4 selected subgingival sites were cultured on blood agar and on Dentaid-1 medium. Suspected pathogens were identified, subcultured, and preserved. The association between the microbiological findings and the clinical status was studied using correlation coefficients (CC). In addition, cats were stratified in subgroups according to presence of putative pathogens, and comparisons were carried out using unpaired t-test. Three bacterial species were frequently detected including Porphyromonas gulae (86%), Porphyromonas circumdentaria (70%) and Fusobacterium nucleatum (90%). The mean proportion of total flora was high for P. gulae (32.54%), moderate for P. circundentaria (8.82%), and low for F. nucleatum (3.96%). Among the clinical variables, tooth mobility was correlated (CC > 0.50, p < 0.001) with recession, pocket depth, attachment level, gingival index, and calculus index (CC = 0.29, p = 0.04) as well as with total bacterial counts (CC = 0.38, p = 0.006). Cats with more than 10% of P. gulae showed significantly more mobility (p = 0.014) and recession (p = 0.038), and a tendency for deeper probing pocket depths (p = 0.084) and attachment loss (p = 0.087). The results from this cross-sectional study confirmed that P. gulae is the most relevant pathogen in periodontal disease in cats.

Efficacy of a new mouth rinse formulation based on 0.07% cetylpyridinium chloride in the control of plaque and gingivitis: a 6-month randomized clinical trial

AIM

To assess the efficacy of a 0.07% cetylpyridinium chloride (CPC) mouth rinse in the control of plaque and gingival inflammation during a 6-month period.

MATERIAL AND METHODS

Adult subjects with moderate gingivitis were selected [≥40% bleeding on marginal probing (BOMP)]. After retrieving microbiological samples and evaluating the clinical parameters (plaque, BOMP and stain indexes), a professional prophylaxis was performed and subjects were randomly assigned to the test (CPC mouth rinse) or to the placebo group. Subjects were re-assessed after 3 and 6 months.

RESULTS

A total of 67 patients (35 test, 32 placebo) were included in the analysis. At 6 months, intra-group significant plaque reductions were observed in the test group (0.691, p < 0.001), but not in the placebo (0.181, p = 0.653). At 6 months, the mean BOMP values were lower in the test group (p = 0.052). Changes between baseline and 6 months were significantly higher in the test group both for plaque (p = 0.002) and BOMP (p = 0.037) when compared with the placebo. A microbiological impact was observed in the test group, especially for Prevotella intermedia.

CONCLUSION

The evaluated 0.07% CPC-based mouth rinse, used three times per day adjunctively to mechanical tooth cleaning, prevents plaque accumulation and gingival inflammation, as compared to the placebo, for at least 6 months.

Evaluation of three selective media for isolation of Aggregatibacter actinomycetemcomitans

BACKGROUND AND OBJECTIVE

Aggregatibacter actinomycetemcomitans is a pathogen in oral and nonoral infections. Detection and quantification of this pathogen can be performed using selective culture techniques. The aim of this study was to establish the efficacy of two known selective media in their ability to select and support the growth of A. actinomycetemcomitans.

MATERIAL AND METHODS

Trypticase soy bacitracin vancomycin (TSBV) medium and brain-heart infusion agar with vancomycin (Dentaid-1), as well as a modified Dentaid-1 medium (in which the brain-heart infusion agar was substituted with brain-heart infusion broth), were compared. Two-hundred and eighteen clinical samples were used to establish the recovery rate, the number of colony-forming units (CFUs) of A. actinomycetemcomitans as well as the total number of CFUs on the three different types of medium. In addition, the numbers of gram-negative aerobic rods and yeasts were determined.

RESULTS

Both types of Dentaid-1 medium showed a higher recovery of A. actinomycetemcomitans compared with TSBV. However, these differences did not reach statistical significance. The total number of CFUs of A. actinomycetemcomitans recovered was significantly higher on Dentaid-1 compared with TSBV (p = 0.029). The mean number of gram-negative aerobic rods recovered was statistically higher on both types of Dentaid-1 medium in comparison with TSBV. Low numbers of yeasts were recovered occasionally on all test plates.

CONCLUSION

Dentaid-1 is a low-cost effective alternative to TSBV for the isolation and growth of A. actinomycetemcomitans from clinical samples, such as dental plaque, which contain a complex microflora.

Are periodontal bacterial profiles and placental inflammatory infiltrate in pregnancy related to birth outcomes?

BACKGROUND

The aim of this study is to determine whether periodontal clinical parameters, periodontal bacterial profiles, and inflammatory infiltrate in placental chorionic villi are associated with adverse pregnancy results.

METHODS

The authors designed an observational case-control study in 244 postpartum females: mothers with preterm/low-birth weight newborns (n = 91 cases) and mothers with full-term, normal-weight infants (n = 153 controls). Sociodemographic, gynecologic, and periodontal variables were gathered for all participants. Data on placental inflammatory infiltrate in biopsies from 68 cases and 65 controls and the gingival bacterial profile in mothers with periodontitis were gathered, detecting associations with bivariate analyses and constructing a multiple logistic regression model with the number of positive inflammatory cells as the dependent variable.

RESULTS

Periodontal values were significantly worse in cases versus controls. Numbers of leukocyte subsets per square millimeters in maternal and fetal vascular spaces were similar between cases and controls. CD45 in maternal placental space was related to the presence of periodontitis (P = 0.029) but not to case or control group (P = 0.264). The anaerobic and commensal bacterial profile in mothers with periodontitis was similar between the groups.

CONCLUSIONS

Periodontal disease was more severe and a periodontitis diagnosis more frequent in mothers with preterm or low-birth weight versus normal delivery. No differences in anaerobic or commensal bacterial profile were found between mothers with periodontitis in the two groups. Local placental factors, such as the nature of the inflammatory infiltrate and slightly higher expression of cyclooxygenase-2 in the females with these adverse pregnancy outcomes, may be related to a subclinical proinflammatory status that could contribute to triggering premature labor.

Probiotic effects of orally administered Lactobacillus reuteri-containing tablets on the subgingival and salivary microbiota in patients with gingivitis. A randomized clinical trial

OBJECTIVE

To investigate the effects of an orally administered probiotic on the oral microbiota.

METHODS

A placebo-controlled, parallel study was conducted in 40 gingivitis subjects during 8 weeks. Treatment consisted on the administration of a daily tablet, either containing Lactobacillus reuteri or placebo. Unstimulated saliva and subgingival samples were collected and analysed by culture and PCR. Clinical and microbiological outcome variables were compared between and within groups.

RESULTS

There were no significant changes between and within the groups in the clinical variables. In saliva, total anaerobic counts after 4 weeks (p = 0.021) and counts of Prevotella intermedia after 8 weeks (p = 0.030), showed reductions in the test group. In subgingival samples, significant reductions in the changes baseline to 4 weeks were observed for P. gingivalis counts (p = 0.008). With PCR, L. reuteri ATCC-PTA-5289 was more frequently detected than L. reuteri DSM-17938.

CONCLUSIONS

The effect of L. reuteri administered in tablets resulted in a reduction in the number of selected periodontal pathogens in the subgingival microbiota, without an associated clinical impact.

Clinical and microbiological efficacy of an antimicrobial mouth rinse containing 0.05% cetylpyridinium chloride in patients with gingivitis

OBJECTIVES

the aim of this study was to evaluate the effects of the use of a mouth rinse and dentifrice with cetylpyridinium chloride (CPC) in patients with gingivitis.

METHODS

the study was designed as a 1-month, double-blind, parallel, randomized clinical trial comparing a negative control regimen (minus active ingredients dentifrice and mouth rinse) with the test products (dentifrice and mouth rinse with 0.05% CPC) in terms of plaque and gingival indexes (PI, GI), patient-based and microbiological outcome variables. The comparisons in relation to the main outcome variables (PI and GI) were made by means of the t-test, either unpaired or paired for the intergroup and intragroup comparisons, respectively.

RESULTS

no differences were detected at baseline. Both groups showed statistically significant decreases in GI (0.17-0.19), without intergroup differences. The PI demonstrated a significant decrease of -0.12 in the test group and minor changes in the negative control group (increase of +0.01). Differences between groups showed a tendency towards statistical significance. A limited impact was observed for microbiological variables in both groups.

CONCLUSION

the results of this study show limited benefits of the evaluated formulations as adjuncts to unsupervised oral hygiene in reducing plaque accumulation, and no effect on gingivitis.

Detection of specific periodontal microorganisms from bacteraemia samples after periodontal therapy using molecular-based diagnostics

AIM

The aim of this study was to assess the presence of subgingival pathogens in peripheral blood samples from periodontitis patients before and after scaling and root planing (Sc/RP) using nested polymerase chain reaction (nested PCR).

MATERIALS AND METHODS

Peripheral blood samples were obtained from 42 patients with severe generalized chronic or aggressive periodontitis. In each patient, four samples of peripheral blood were drawn at different times: immediately before the Sc/RP procedure; immediately after Sc/RP; 15 and 30 min. post-Sc/RP. Blood samples were analysed for bacteraemia with anaerobic culturing and nested PCR, using universal bacterial primers that target the 16S-rRNA gene of most bacteria, subsequently re-amplified with specific primers to Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Eikenella corrodens, Campylobacter rectus and Prevotella intermedia, using a modified phenol-chloroform method for DNA extraction.

RESULTS

Presence of specific periodontal pathogens in peripheral blood after treatment was detected in 54.8% of the patients, in 47.6% with anaerobic culturing and in 19% with nested PCR. In 16.6%, the periodontal pathogens were detected before Sc/RP. P. gingivalis and A. actynomicetemcomitans were the pathogens most frequently detected in the bloodstream before and after Sc/RP.

CONCLUSIONS

Nested PCR demonstrated the presence of DNA from periodontal pathogens in blood samples in severe periodontitis patients before, during and after periodontal therapy. The use of these molecular-based techniques may improve the accuracy from the results obtained by haemoculture.

Detection of periodontal bacterial DNA in serum and synovial fluid in refractory rheumatoid arthritis patients

AIM

To identify periodontal bacterial DNA (PBDNA) by PCR in subgingival dental plaque (SDP), serum and synovial fluid (SF) of rheumatoid arthritis (RA) with periodontal disease (PD) patients and to explore the possible PBDNA transport pathways from mouth to joints.

METHODS

This cross-sectional prolective study involved 19 subjects with RA and PD. Informed consent, health and dental questionnaires were obtained. SDP, SF and serum samples were obtained, and leucocytes were isolated from blood. DNA was extracted and PCR assays to detect main PD species were carried out. Cultures on agar plates and broth, from each sample, were performed.

RESULTS

Hundred percentage of patients showed PBDNA in SDP and SF and 83.5% in serum. Prevotella intermedia (89.4% and 73.6%) and Porphyromonas gingivalis (57.8% and 42.1%) were the species most frequently detected in SDP and SF, respectively. In SDP, 4.05 different bacterial species were found followed by 1.19 in serum and 2.26 in SF. Culture onto agar plates and broth did not show any bacterial growth, leucocytes were not positive to PBDNA by PCR.

CONCLUSION

This study suggests that PBDNA could have a role on the RA aetiology. The possible pathway of transport of PBDNA from mouth to joints could be via the free form of DNA.

Efficacy of a low-concentration chlorhexidine mouth rinse in non-compliant periodontitis patients attending a supportive periodontal care programme: a randomized clinical trial

OBJECTIVE

To assess the clinical and microbiological efficacy of a 0.05% chlorhexidine and 0.05% cetyl-pyridinium chloride mouth rinse in supportive periodontal care (SPC) in patients with inadequate plaque control.

MATERIAL AND METHODS

The study was a randomized, double-blinded, placebo-controlled clinical trial in patients with moderate to severe chronic periodontitis under SPC with an inadequate plaque control (Turesky index >1). After supragingival prophylaxis and oral hygiene reinforcement, participants rinsed twice a day for 3 months with the test or placebo solutions, in addition to conventional hygiene. Primary clinical outcome variables included plaque and gingival indices. As secondary outcomes, periodontal and microbiological variables were studied. ancova and chi(2) tests were used to compare the variables.

RESULTS

Forty-seven patients (22 placebo and 25 test group) participated. After 3 months, plaque levels increased in the placebo group, while diminished in the test group (p<0.001). Similar effects were found for bleeding on probing. The other clinical parameters did not show significant differences. Microbiological variables demonstrated inter-group significant reductions in subgingival counts of Fusobacterium nucleatum and Prevotella intermedia and a decrease of the total bacterial counts in saliva.

CONCLUSIONS

The tested mouth rinse demonstrated efficacy in reducing plaque and gingivitis, as well as in decreasing the microbial load in saliva and gingival sulcus.

Evaluation of two local drug delivery systems as adjuncts to mechanotherapy as compared to mechanotherapy alone in management of chronic periodontitis: A clinical, microbiological, and molecular study

BACKGROUND

Modern concepts of treating inflammatory periodontal disease aim at changes in the subgingival ecosystems within the periodontal pockets to alter the complex microbial community into a microbiota compatible with good periodontal health. Systemic antimicrobial therapy, although effective, involves a relatively high dose with repeated intakes over a prolonged period of time to achieve the required inhibitory concentrations in the sulcular fluid. The adjunctive use of local drug delivery may provide a beneficial response, especially in specific areas where conventional forms of therapy might fail. The aim of this study was to compare the efficacy of two local drug delivery systems, one containing metronidazole and the other containing tetracycline hydrochloride as adjuncts to mechanotherapy in the treatment of chronic periodontitis.

MATERIALS AND METHODS

There were three groups that were labeled as group A (Scaling + Tetracycline), group B (Scaling + Metronidazole), and group C (Scaling alone). A microbiological analysis was carried out to determine the efficacy of these systems in changing the pathogenic flora in deep pockets. In addition, a multiplex polymerase chain reaction was carried out to confirm the presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis (Pg), and Tannerella forsythensis in the flora associated with chronic periodontitis.

RESULTS

There was clinical improvement in groups A and B, which correlated with an improvement in the microbiological parameters; these results were sustained for 90 days following therapy. In Group C, the flora showed a shift towards baseline at the end of 90 days.

CONCLUSIONS

According to this study, both the local antibiotic therapies resulted in greater improvement in microbiological parameters when used as an adjunct to mechanotherapy as compared to mechanotherapy alone.

A novel selective medium for isolation of Aggregatibacter (Actinobacillus) actinomycetemcomitans

BACKGROUND AND OBJECTIVE

Conventional selective media have been used for the selection of Aggregatibacter (Actinobacillus) actinomycetemcomitans in clinical samples. The proportion of A. actinomycetemcomitans grown on the selective media in vitro may not reflect the true counts in vivo because of the low selectivity. A novel selective medium, designated AASM, was developed for the isolation of A. actinomycetemcomitans.

MATERIAL AND METHODS

AASM was prepared by adding of 200 microg/mL of vancomycin and 10 U/mL of bacitracin to AAGM, which contains dextrose, sodium bicarbonate, trypticase soy, yeast extract and agar. Clinical efficacy was evaluated by the recovery, on AASM, of A. actinomycetemcomitans from subgingival samples of 44 periodontally healthy subjects and 76 patients with chronic periodontitis.

RESULTS

All serotypes (a-f) of A. actinomycetemcomitans strains grew well, and the average growth recovery of A. actinomycetemcomitans on AASM medium was 94.4% (80.0-109.7%) of that on AAGM. The exclusive rate of other bacteria was 99.9% in clinical samples cultured on AASM. A. actinomycetemcomitans was not detected in periodontally healthy persons but was detected in 25 (32.9%) patients with chronic periodontitis. The predominant serotype was c, detected in 11 subjects.

CONCLUSION

The new selective medium, AASM, was highly selective for A. actinomycetemcomitans, eliminated possible false-positive results and was useful for the isolation of A. actinomycetemcomitans from clinical samples.