Microbiological and Clinical Effects of Sitafloxacin and Azithromycin in Periodontitis Patients Receiving Supportive Periodontal Therapy

Construction of a versatile in vitro cultivation screening platform using human oral microbiota

We developed a simulation model of human oral microbiota using Bio Palette oral medium (BPOM) containing 0.02% glucose and lower bacterial nitrogen sources, derived from saliva and dental plaque. By decreasing the concentration of Gifu anaerobic medium (GAM) from 30 to 10 g L-1 , we observed increased ratios of target pathogenic genera, Porphyromonas and Fusobacterium from 0.5% and 1.7% to 1.2% and 3.5%, respectively, in the biofilm on hydroxyapatite (HA) discs. BPOM exhibited the higher ratios of Porphyromonas and Fusobacterium, and amplicon sequence variant number on HA, compared with GAM, modified GAM and basal medium mucin. Mixing glycerol stocks of BPOM culture solutions from four human subjects resulted in comparable ratios of these bacteria to the original saliva. In this simulation model, sitafloxacin showed higher inhibitory effects on P. gingivalis than minocycline hydrochloride at a low dosage of 0.1 μg mL-1 . Probiotics such as Streptococcus salivarius and Limosilactobacillus fermentum also showed significant decreases in Porphyromonas and Fusobacterium ratios on HA, respectively. Overall, the study suggests that BPOM with low carbon and nutrients could be a versatile platform for assessing the efficacy of antibiotics and live biotherapeutics in treating oral diseases caused by Porphyromonas and Fusobacterium.

Periodontal therapy for localized severe periodontitis in a patient receiving fixed orthodontic treatment: a case report

BACKGROUND

Orthodontic treatment involves movement of teeth by compression and resorption of the alveolar bone using orthodontic forces. These movements are closely linked to the interactions between the teeth and the periodontal tissues that support them. Owing to an increase in adults seeking orthodontic treatment, orthodontists increasingly encounter patients with periodontal diseases, in whom orthodontic treatment is contraindicated. In rare cases, periodontitis may develop after treatment initiation. However, no approach for treating periodontitis after the initiation of orthodontic treatment has been established. Here, we present an approach for managing localized severe periodontitis manifesting after initiating orthodontic treatment.

CASE PRESENTATION

A 32-year-old Japanese woman was referred to the Department of Dentistry and Oral Surgery by an orthodontist who observed symptoms of acute periodontitis in the maxillary molars that required periodontal examination and treatment. A detailed periodontal examination, including oral bacteriological examination, revealed localized severe periodontitis (stage III, grade B) in the maxillary left first and second molars and in the mandibular right second molar. After consultation with the orthodontist, the orthodontic treatment was suspended based on the results of the bacteriological examination to allow for periodontal treatment. Full-mouth disinfection was performed with adjunctive oral sitafloxacin. Periodontal and bacteriological examinations after treatment revealed regression of the localized periodontitis with bone regeneration. Thereafter, orthodontic treatment was resumed, and good progress was achieved.

CONCLUSIONS

Orthodontists should recognize the risk of acute severe periodontitis in young adults. Asymptomatic patients with localized severe periodontitis may clear a screening test before orthodontic treatment but develop acute symptoms with bone resorption during orthodontic treatment. Therefore, patients requiring orthodontic treatment should be examined by their family dentist or a periodontist to rule out periodontal issues that may impede orthodontic treatment. The patients should also be informed of age-related risks. Further, periodontists, family dentists, and orthodontists who treat adults should be informed about periodontitis and the need for interdisciplinary collaboration. In patients who develop periodontitis after orthodontic treatment initiation, temporary interruption of orthodontic treatment and aggressive periodontal intervention may facilitate recovery.

Sitafloxacin Expresses Potent Anti-Mycobacterium abscessus Activity

Therapeutic options for treating Mycobacterium abscessus infections are extremely limited; quinolones are important. The in vitro anti-M. abscessus activities of nine quinolones, emphasizing sitafloxacin, were investigated. Antimicrobial susceptibility testing was performed on 10 non-tuberculous mycobacterium reference strains and 194 clinical, M. abscessus isolates. The activity of sitafloxacin against intracellular M. abscessus residing within macrophages was also evaluated. A checkerboard assay was conducted to determine synergy between sitafloxacin and 10 clinically important antibiotics. Among the nine quinolones tested, sitafloxacin exhibited the greatest anti-M. abscessus activity with MIC₅₀ and MIC₉₀ of 1 and 2 mg/L, respectively. Sitafloxacin exerted a bacteriostatic effect on M. abscessus and inhibited the intracellular growth of M. abscessus at concentrations equivalent to clarithromycin. No antagonism between sitafloxacin and 10 clinically important anti-M. abscessus antibiotics was evident. In summary, sitafloxacin exhibited a significant advantage relative to other quinolones in inhibiting the growth of M. abscessus in vitro, suggesting the potential inclusion of sitafloxacin in new strategies to treat M. abscessus infections.

Systemic azithromycin as an adjunct to scaling and root planing in patients with stage III/IV periodontitis: 12-month results of a randomized controlled clinical trial

OBJECTIVES

To determine whether azithromycin (AZI) as an adjunct to scaling and root planing (SRP), when compared to placebo, decreases the number of sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 12 months post-treatment in stage III/IV periodontitis patients.

MATERIALS AND METHODS

In a double-blind randomized parallel-arm placebo-controlled trial, 40 stage III/IV periodontitis patients received steps 1 and 2 of periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20; AZI 500 mg/day, 3 days) or placebo (n = 20). Additional instrumentation of residual diseased sites (DS) - sites with PD ≥ 5 mm and BOP - was performed at the 3-, 6- and 9-month follow-ups. The primary outcome variable was the number of DS at the 12-month re-evaluation. Using a multivariate multilevel logistic regression model, the effects of gender, age, antibiotic therapy, presence of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated.

RESULTS

The number of DS after 12 months was similar in the test (median (Me) = 4, interquartile range (IQR) = 0-6) and control (Me = 3, IQR = 1-6.5) groups. Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroup differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio (OR) for the healing of DS on molars (OR = 0.29; p < 0.001) and in smokers (OR = 0.36; p = 0.048).

CONCLUSION

Stage III/IV periodontitis patients showed significant but comparable improvements in periodontal parameters and the number of residual DS at the 12-month revaluation regardless of treatment type. This may have been the result of the additional instrumentation received by patients at residual DS in both treatment groups.

CLINICAL RELEVANCE

Treatment with AZI + SRP provided no additional benefits after 12 months in terms of periodontal parameters or the number of persisting sites with PD ≥ 5 mm + BOP as compared to SRP plus placebo.

TRIAL REGISTRATION

EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.

Inhibitory effects of azithromycin on the adherence ability of Porphyromonas gingivalis

BACKGROUND

Porphyromonas gingivalis is a major pathogen and has a high detection rate in periodontal disease. Fimbriae and hemagglutinin are expressed by P. gingivalis, and these play an important role in the adherence of the bacteria to periodontal tissue and biofilm formation. The aim of this study was to investigate the effects of sub-minimal inhibitory concentrations (sub-MICs) of azithromycin on the adherence of P. gingivalis, focusing on the inhibition of fimbriae expression and hemagglutinin activity.

METHODS

P. gingivalis ATCC 33277 were incubated anaerobically with sub-MICs of azithromycin at 37°C by gentle shaking for 18 hours. The bacterial cells were harvested, washed twice with phosphate-buffered saline (PBS), and the proteins analyzed by 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. Adherence assay and hemagglutinin activity tests were done with the same culture.

RESULTS

The results of SDS-PAGE indicated that the sub-MICs of azithromycin inhibited 41-kDa fimbrial protein expression and hemagglutinin activities. The disappearance of 41-kDa fimbrial protein expression and long fimbriae in 0.4 µg/mL, 0.2 µg/mL, and 0.1 µg/mL of azithromycin was confirmed by western blotting and transmission electron microscopy. The adherence of P. gingivalis to human gingival epithelial cells was reduced by sub-MICs of azithromycin compared with the adherence levels without antibiotic.

CONCLUSIONS

These results suggest that sub-MICs of azithromycin may reduce the adherence of P. gingivalis to host cells, by inhibiting production of fimbriae and hemagglutinin activities. Therefore, azithromycin can be used as a biofilm treatment of periodontal disease caused by P. gingivalis.

Optimal design of thiostrepton-derived thiopeptide antibiotics and their potential application against oral pathogens

A new fluorinated thiostrepton-type thiopeptide antibiotic was designed and biosynthesized by using a biological approach with synthetic advantages. Related bioassays indicated that thiostrepton and its derivatives hold potential in oral pathogen treatment.

Supportive periodontal therapy (SPT) for maintaining the dentition in adults treated for periodontitis

BACKGROUND

Periodontitis is a bacterially-induced, chronic inflammatory disease that destroys the connective tissues and bone that support teeth. Active periodontal treatment aims to reduce the inflammatory response, primarily through eradication of bacterial deposits. Following completion of treatment and arrest of inflammation, supportive periodontal therapy (SPT) is employed to reduce the probability of re-infection and progression of the disease; to maintain teeth without pain, excessive mobility or persistent infection in the long term, and to prevent related oral diseases.According to the American Academy of Periodontology, SPT should include all components of a typical dental recall examination, and importantly should also include periodontal re-evaluation and risk assessment, supragingival and subgingival removal of bacterial plaque and calculus, and re-treatment of any sites showing recurrent or persistent disease. While the first four points might be expected to form part of the routine examination appointment for periodontally healthy patients, the inclusion of thorough periodontal evaluation, risk assessment and subsequent treatment - normally including mechanical debridement of any plaque or calculus deposits - differentiates SPT from routine care.Success of SPT has been reported in a number of long-term, retrospective studies. This review aimed to assess the evidence available from randomised controlled trials (RCTs).

OBJECTIVES

To determine the effects of supportive periodontal therapy (SPT) in the maintenance of the dentition of adults treated for periodontitis.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 8 May 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 5), MEDLINE Ovid (1946 to 8 May 2017), and Embase Ovid (1980 to 8 May 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating SPT versus monitoring only or alternative approaches to mechanical debridement; SPT alone versus SPT with adjunctive interventions; different approaches to or providers of SPT; and different time intervals for SPT delivery.We excluded split-mouth studies where we considered there could be a risk of contamination.Participants must have completed active periodontal therapy at least six months prior to randomisation and be enrolled in an SPT programme. Trials must have had a minimum follow-up period of 12 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify studies for inclusion, assessed the risk of bias in included studies and extracted study data. When possible, we calculated mean differences (MDs) and 95% confidence intervals (CIs) for continuous variables. Two review authors assessed the quality of evidence for each comparison and outcome using GRADE criteria.

MAIN RESULTS

We included four trials involving 307 participants aged 31 to 85 years, who had been previously treated for moderate to severe chronic periodontitis. Three studies compared adjuncts to mechanical debridement in SPT versus debridement only. The adjuncts were local antibiotics in two studies (one at high risk of bias and one at low risk) and photodynamic therapy in one study (at unclear risk of bias). One study at high risk of bias compared provision of SPT by a specialist versus general practitioner. We did not identify any RCTs evaluating the effects of SPT versus monitoring only, or of providing SPT at different time intervals, or that compared the effects of mechanical debridement using different approaches or technologies.No included trials measured our primary outcome 'tooth loss'; however, studies evaluated signs of inflammation and potential periodontal disease progression, including bleeding on probing (BoP), clinical attachment level (CAL) and probing pocket depth (PPD).There was no evidence of a difference between SPT delivered by a specialist versus a general practitioner for BoP or PPD at 12 months (very low-quality evidence). This study did not measure CAL or adverse events.Due to heterogeneous outcome reporting, it was not possible to combine data from the two studies comparing mechanical debridement with or without the use of adjunctive local antibiotics. Both studies found no evidence of a difference between groups at 12 months (low to very low-quality evidence). There were no adverse events in either study.The use of adjunctive photodynamic therapy did not demonstrate evidence of benefit compared to mechanical debridement only (very low-quality evidence). Adverse events were not measured.The quality of the evidence is low to very low for these comparisons. Future research is likely to change the findings, therefore the results should be interpreted with caution.

AUTHORS' CONCLUSIONS

Overall, there is insufficient evidence to determine the superiority of different protocols or adjunctive strategies to improve tooth maintenance during SPT. No trials evaluated SPT versus monitoring only. The evidence available for the comparisons evaluated is of low to very low quality, and hampered by dissimilarities in outcome reporting. More trials using uniform definitions and outcomes are required to address the objectives of this review.

Antimicrobial susceptibility profiles of oral Treponema species

Treponemes occur in the microflora of the dental plaque. Certain Treponema species that are frequently isolated from chronic periodontitis lesions are involved in its initiation and progression. In addition to mechanical instrumentation, antimicrobial agents are used as an adjunctive treatment modality for periodontitis. Despite its importance for successful antimicrobial treatment, information about susceptibility is limited for Treponema species. The aim of this study was to assess the susceptibility of Treponema denticola strains, Treponema socranskii, and Treponema vincentii to eleven antimicrobial agents. The minimum inhibitory and minimum bactericidal concentrations of these antimicrobial agents revealed strain-specific variation. Doxycycline, minocycline, azithromycin, and erythromycin were effective against all Treponema species tested in this study, whereas fluoroquinolones only exhibited an equivalent effectiveness on T. socranskii. The susceptibility of one T. denticola strain, T. socranskii, and T. vincentii to kanamycin was influenced by prior exposure to aerobic conditions. The susceptibility to quinolone drugs varied among strains of T. denticola, although they share an amino acid sequence identity of greater than 99% for DNA gyrase (type II topoisomerase) subunit A. In addition, an ATP-binding cassette (ABC) transporter inhibitor assay for T. denticola indicated that the transport of quinolone drugs is partially related to this transporter, although there may be parallel transport mechanisms. Our results provide important insights into antimicrobial agent-Treponema dynamics and establish a basis for developing an appropriate adjunctive therapy for periodontal disease.