Aim This study compared the subgingival microbiota of subjects with refractory periodontitis (RP) to those in subjects with treatable periodontitis (GR) or periodontal health (PH) using the Human Oral Microbe Identification Microarray (HOMIM). Methods At baseline, subgingival plaque samples were taken from 47 periodontitis and 20 PH individuals, and analyzed for the presence of 300 species by HOMIM. The periodontitis subjects were classified as RP (n=17) based on mean attachment loss (AL) and/or >3 sites with AL ≥2.5 mm after SRP, surgery and systemically administered amoxicillin and metronidazole or as GR (n=30) based on mean attachment gain and no sites with AL ≥2.5 mm after treatment. Significant differences in taxa among groups were sought using the Kruskal Wallis and Chi-square tests. Results More species were detected in diseased patients (GR or RP) than those without disease (PH). RP subjects were distinguished from GR and PH by a significantly high frequency of putative periodontal pathogens such as, Parvimonas micra, Campylobacter gracilis, Eubacterium nodatum, Selenomonas noxia, Tannerella forsythia, Porphyromonas gingivalis, Prevotella spp., Treponema spp., Eikenella corrodens, as well as “unusual” species (Pseudoramibacter alactolyticus, TM7 spp. oral taxon (OT) 346/356, Bacteroidetes spp. OT 272/274, Solobacterium moorei, Desulfobulbus sp. OT 041, Brevundimonas diminuta, Sphaerocytophaga sp. OT 337, Shuttleworthia satelles, Filifactor alocis, Dialister invisus/pneumosintes, Granulicatella adiacens, Mogibacterium tidmidum, Veillonella atypica, Mycoplasma salivarium, Synergistes sp. cluster II, Acidaminococcaceae [G-1] sp. OT 132/150/155/148/135) [p<0.05]. Species that were more prevalent in PH than in periodontitis patients included Actinomyces sp. OT 170, Actinomyces spp. cluster I, Capnocytophaga sputigena, Cardiobacterium hominis, Haemophilus parainfluenzae, Lautropia mirabilis, Propionibacterium propionicum, Rothia dentocariosa/mucilagenosa, Streptococcus sanguinis (p<0.05). Conclusion RP patients present a distinct microbial profile compared to patients in the GR and PH groups as determined by HOMIM.

The purpose of this investigation was to compare the clinical parameters and the site prevalence and levels of 40 subgingival species in successfully treated and refractory periodontitis subjects. 94 subjects received scaling and root planing and if needed, periodontal surgery and systemically administered tetracycline. 28 refractory subjects showed mean full mouth attachment loss and/or > 3 sites showing attachment loss > 2.5 mm within 1 year post-therapy. 66 successfully treated subjects showed mean attachment level gain and no sites with attachment loss > 2.5 mm. Baseline subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 40 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and % of sites colonized by each species (prevalence) was computed for each subject and differences between groups sought using the Mann-Whitney test. Most of the 40 species tested, including Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Bacteroides forsythus, were equally or less prevalent in the refractory group. Prevotella nigrescens was significantly more prevalent in successfully treated subjects, while refractory subjects harbored a larger proportion of Streptococcus species, particularly Streptococcus constellatus. The odds of a subject being refractory was 8.6 (p < 0.001) if S. constellatus constituted > or = 3.5% of the total DNA probe count. Since few microbiological differences existed between treatment outcome groups using DNA probes to known species, the predominant cultivable microbiota of 33 subgingival samples from 14 refractory subjects was examined. 85% of the 1649 isolates were identified using probes to 69 recognized subgingival species. The remaining unidentified strains were classified by analyzing 16S rRNA gene sequences. Many sequenced isolates were of taxa not considered a common part of the oral microbiota such as Acinetobacter baumanni, Gemella haemolysans, Enterococcus faecalis, Staphylococcus warneri, Pseudomonas aeruginosa and novel species in the genera Bartonella, Ralstonia, Neisseria, Eubacterium, Rothia, Gordona, Gemella, Corynebacterium, Leptotrichia, and Actinomyces. Refractory subjects constituted a heterogeneous group based on their subgingival microbiota. As a group, they did not harbor more of the "classic" periodontopathogens, although elevated proportions of S. constellatus were found.

Aim This study compared the changes on the subgingival microbiota of subjects with “refractory” periodontitis (RP) or treatable periodontitis (GR) before and after periodontal therapy by using the Human Oral Microbe Identification Microarray (HOMIM). Methods Individuals with chronic periodontitis were classified as RP (n=17) based on mean attachment loss (AL) and/or >3 sites with AL ≥2.5 mm after scaling and root planing, surgery and systemically administered amoxicillin and metronidazole or as GR (n=30) based on mean attachment gain and no sites with AL ≥2.5 mm after treatment. Subgingival plaque samples were taken at baseline and 15 months after treatment and analyzed for the presence of 300 species by HOMIM analysis. Significant differences in taxa before and after therapy were sought using the Wilcoxon test. Results The majority of species evaluated decreased in prevalence in both groups after treatment; however, only a small subset of organisms was significantly affected. Species that increased or persisted in high frequency in RP but were significantly reduced in GR included Bacteroidetes sp., Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella spp., Tannerella forsythia, Dialister spp., Selenomonas spp., Catonella morbi, Eubacterium spp., Filifactor alocis, Parvimonas micra, Peptostreptococcus sp. OT113, Fusobacterium sp. OT203, Pseudoramibacter alactolyticus, Streptococcus intermedius or Streptococcus constellatus and Shuttlesworthia satelles. In contrast, Capnocytophaga sputigena, Cardiobacterium hominis, Gemella haemolysans, Haemophilus parainfluenzae, Kingella oralis, Lautropia mirabilis, Neisseria elongata, Rothia dentocariosa, Streptococcus australis and Veillonella spp. were more associated with therapeutic success. Conclusion Persistence of putative and novel periodontal pathogens, as well as low prevalence of beneficial species was associated with chronic “refractory” periodontitis.

Aim: To determine microbial profiles that discriminate periodontal health from different forms of periodontal diseases. Methods: Subgingival biofilm was obtained from patients with periodontal health (27), gingivitis (11), chronic periodontitis (35) and aggressive periodontitis (24), and analysed for the presence of >250 species/phylotypes using HOMIM. Microbial differences among groups were examined by Mann-Whitney U-test. Regression analyses were performed to determine microbial risk indicators of disease. Conclusion: There were specific microbial signatures of the subgingival biofilm that were able to distinguish between microbiomes of periodontal health and diseases. Such profiles may be used to establish risk of disease.

The subgingival microbiota of Brazilians with untreated chronic periodontitis were complex, including high proportions of periodontopathogens commonly found in other populations, as well as some unusual species.

AMX + MET brought additional clinical effects to the repeated mechanical and antiseptic treatment of GAgP in a very short time (3 months), which tended to fade away over time (6 months).

Systemic AMX+MET or placebos adjunctive to anti-infective mechanical debridement were comparable in lowering periodontal pathogens up to 6 months after treatment. Species not commonly associated with GAP were less affected by both therapies.

The ecological diversity of the periodontal microenvironment may provide suitable conditions for the colonization of species not usually considered members of the oral microbiota. In this investigation, we aimed to determine the prevalence and levels of pathogenic species of medical relevance in the microbiota of individuals with distinct periodontal clinical status. Subgingival biofilm was obtained from patients with periodontal health (H, n = 81), gingivitis (G, n = 55), generalized aggressive (AgP, n = 36) or chronic periodontitis (CP, n = 98), and analyzed for 39 microbial taxa using a checkerboard DNA-DNA hybridization technique. Microbial differences among groups, as well as associations between clinical and microbiological parameters were sought by non-parametric and univariate correlation tests. Neisseria spp., Peptostreptococus anaerobius, Candida albicans, enterobacteria, Pseudomonas aeruginosa, Eubacterium saphenum, Clostridium difficile and Olsenella uli were detected in high mean prevalence and counts in the subgingival microbiota of the study population. Species that were more related to periodontal inflammation and tissue destruction at the patient and site levels included enterobacteria, C. albicans, Neisseria spp., P. aeruginosa, O. uli, Hafnia alvei, Serratia marcescens and Filifactor alocis (p < 0.05). In contrast, Fusobacterium necrophorum, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus pneumoniae were associated with periodontal health (p < 0.05). Pathogenic species of medical importance may be detected in high prevalence and levels in the periodontal microbiota. Regardless of their role in periodontal health or disease, the periodontal biofilm may be a source for dissemination and development of systemic infections by these pathogenic microorganisms.