Subgingival microbiota of Brazilian subjects with untreated chronic periodontitis

BACKGROUND: Different periodontopathogenic microbiota have been associated with periodontal diseases in several populations. The present investigation determined the subgingival microbiota of untreated chronic periodontitis Brazilians using the checkerboard DNA-DNA hybridization technique. METHODS: Twenty-five periodontitis patients (mean age, 41 +/- 2; mean probing depth [PD], 3.3 +/- 0.2; mean attachment level [AL], 3.6 +/- 0.2) with no history of previous periodontal therapy and a control group of 14 healthy subjects (mean age, 34 +/- 0.6; mean PD, 1.8 +/- 0.2; mean AL, 1.7 +/- 0.1) were selected. Measurements of PD, AL, bleeding on probing, plaque accumulation, and suppuration were recorded at 6 sites/tooth. Subgingival plaque samples were obtained from 4 sites in each tooth/subject in both groups. The presence and levels of 41 subgingival species were determined in 4,032 plaque samples using whole genomic DNA probes and the checkerboard method. RESULTS: Periodontal pathogens, as well as some unusual species (E. faecalis, E. coli and Bartonella sp.), were detected significantly more often and/or in higher levels in the periodontitis group (P < 0.05). Most species were more frequently detected in interproximal sites. B. forsythus, P. gingivalis, E. nodatum, and F. nucleatum ss vincentii showed a significant positive correlation with mean PD and AL (P < 0.05). CONCLUSIONS: 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.     

Subgingival microbiota of chronic periodontitis subjects from different geographic locations

BACKGROUND: Most clinical studies assume that the subgingival microbiota is similar from one geographic location to another. The purpose of the present investigation was to examine the composition of the subgingival microbiota in chronic periodontitis subjects from four countries. METHOD: Subjects with chronic periodontitis (N, Sweden=101; USA=115; Brazil=58; Chile=26) were recruited. Subjects were measured at baseline for plaque, gingivitis, bleeding on probing (BOP), suppuration, pocket depth (PD) and attachment level (AL) at six sites per tooth. Subgingival plaque samples taken from the mesial aspect of each tooth at baseline were individually analyzed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization (total samples=6036). % DNA probe counts comprised by each species was determined for each site and averaged across sites in each subject. Significance of differences in proportions of each species among countries was determined using ancova adjusting for age, mean pocket depth, gender and smoking status. p-Values were adjusted for multiple comparisons. RESULTS: On average, all species were detected in samples from subjects in the four countries. Thirteen species differed significantly in adjusted mean proportions among countries even after adjusting for multiple comparisons. Porphyromonas gingivalis, one species that differed in proportions among countries, comprised adjusted means of 7.5, 11.9, 1.6 and 6.6% of the microbiota in subjects from Brazil, Chile, Sweden and USA (p<0.001), while mean proportions of Treponema denticola were 6.7, 4.2, 0.8 and 2.3, respectively (p<0.001). In contrast, a key periodontal pathogen, Tannerella forsythensis, exhibited mean proportions ranging from 6.2-8.5% and did not differ significantly among countries. Besides these species, prominent species in Brazil were Actinomyces naeslundii genospecies 1 and 2 (8.4%, 7.2%) and Prevotella intermedia (6.5%); in Chile, Prevotella melaninogenica (6.4%) and Neisseria mucosa (5.3%); in Sweden A. naeslundii genospecies 2 (8.4%), Capnocytophaga gingivalis (7.1%) and Peptostreptococcus micros (5.0%); in USA A. naeslundii genospecies 2 (7.5%), P. intermedia (6.8%) and C. gingivalis (6.1%). CONCLUSIONS: The microbial profiles of subgingival plaque samples from chronic periodontitis subjects in four countries showed surprisingly marked differences. These differences persisted after adjusting for age, mean pocket depth, gender and smoking status.     

Subgingival temperature and microbiota in initial periodontitis

Abstract. The association between subgingival temperature, other clinical characteristics, and the subgingival microbiota was examined in adult subjects with initial periodontitis and differing levels of gingival inflammation, 43 subjects were measured at 6 sites per tooth for pocket depth, attachment level, presence of plaque, gingival redness, bleeding on probing and subgingival temperature at 3-month intervals for 1 year. Subgingival plaque was sampled from 15 initial active periodontitis sites (10 subjects), 121 gingivitis, sites (20 subjects) and 202 healthy sites (13 subjects), and included the 5 hottest and 5 coldest sites in each subject. Plaque samples were analyzed for 13 subgingival species using whole-genomic DNA probes. The major influences on the subgingival microbiota were the clinical status of sites, pocket depth, and the presence of supragingival plaque. No significant association between species and site temperature was observed. Initial active sites were associated with Bacteroides forsythus and Campylobacter rectus. and had a higher mean subgingival temperature and deeper mean pocket depth than inactive sites, A weak association between pocket depth and site temperature was noted. The major influence on subgingival temperature of sites was the anterior to posterior anatomical temperature gradient in the mandible and maxilla.     

Subgingival and tongue microbiota during early periodontitis

Periodontal infections have a microbial etiology. Association of species with early disease would be useful in determining which microbes initiate periodontitis. We hypothesized that the microbiota of subgingival and tongue samples would differ between early periodontitis and health. A cross-sectional evaluation of 141 healthy and early periodontitis adults was performed with the use of oligonucleotide probes and PCR. Most species differed in associations with sample sites; most subgingival species were associated with subgingival samples. Few species were detected more frequently in early periodontitis by DNA probes. Porphyromonas gingivalis and Tannerella forsythia (Tannerella forsythensis) were associated with early periodontitis by direct PCR. In conclusion, the microbiota of tongue samples was less sensitive than that of subgingival samples in detecting periodontal species, and there was overlap in species detected in health and early periodontitis. Detection of periodontal pathogens in early periodontitis suggests an etiology similar to that of more advanced disease.     

Subgingival microbiota in adult Down syndrome periodontitis

Khocht A, Yaskell T, Janal M, Turner BF, Rams TE, Haffajee AD, Socransky SS. Subgingival microbiota in adult Down syndrome periodontitis. J Periodont Res 2012; 47: 500–507. © 2012 John Wiley & Sons A/S Background and Objective: The subgingival microbiota in Down syndrome and non‐Down syndrome adults receiving periodic dental care was examined for 40 bacterial species using checkerboard DNA–DNA hybridization and the results were related to clinical periodontal attachment loss. Material and Methods: A total of 44 Down syndrome, 66 non‐Down syndrome mentally retarded and 83 mentally normal adults were clinically evaluated. This involved, for each subject, the removal of subgingival specimens from three interproximal sites on different teeth; all subgingival samples per subject were then pooled and assessed for the presence and levels of 40 bacterial species using species‐specific whole‐genomic DNA probes and checkerboard DNA–DNA hybridization. Significant group differences in species proportions averaged across subjects were evaluated using the Kruskal–Wallis test, and associations between subgingival species and mean subject attachment loss within Down syndrome and non‐Down syndrome subject groups were quantified using Pearson correlation and multiple linear regression analysis. Results: Down syndrome subjects exhibited greater attachment loss than non‐Down syndrome subjects (p = 0.05). Most microbial species were present in Down syndrome subjects at levels similar to non‐Down syndrome subjects, except for higher proportions of Selenomonas noxia, Propionibacterium acnes, Streptococcus gordonii, Streptococcus mitis and Streptococcus oralis in Down syndrome subjects compared with non‐Down syndrome study subjects, higher proportions of Treponema socranskii in Down syndrome subjects compared with non‐Down syndrome mentally retarded subjects, and higher proportions of Streptococcus constellatus in Down syndrome subjects compared with mentally normal subjects. Down syndrome adults classified with periodontitis revealed higher subgingival levels of T. socranskii than Down syndrome subjects with no periodontitis (p = 0.02). Higher subgingival proportions of S. constellatus, Fusobacterium nucleatum ssp. nucleatum, S. noxia and Prevotella nigrescens showed significant positive correlations (r = 0.35–0.42) and higher proportions of Actinomyces naeslundii II and Actinomyces odontolyticus showed negative correlations (r = ?0.36 to ?0.40), with increasing mean subject attachment loss in Down syndrome adults. Conclusion: Individuals with Down syndrome show higher levels of some subgingival bacterial species and specific associations between certain subgingival bacterial species and loss of periodontal attachment. These findings are consistent with the notion that certain subgingival bacteria may contribute to the increased level of periodontal disease seen in Down syndrome individuals and raise the question as to the reason for increased colonization in Down syndrome.     

Subgingival microbiota of periodontally untreated Mexican subjects with generalized aggressive periodontitis

BACKGROUND AND AIM: Specific microbial profiles that may distinguish between generalized aggressive-periodontitis (GAgP) and generalized chronic-periodontitis (GCP) have, to date, not been described. The purpose of the present study was to describe the subgingival microbial composition of Mexican subjects with GAgP and compare it with that of individuals with GCP and periodontal health (PH). MATERIAL AND METHODS: Seventy-seven subjects with GAgP (n=19), GCP (n=39) and PH (n=19) were selected. Clinical measurements included plaque accumulation, gingival erythema, bleeding on probing, suppuration, pocket depth and attachment level. Up to 28 subgingival plaque samples were obtained from each subject and analysed using the checkerboard DNA-DNA hybridization technique. RESULTS: GAgP and GCP subjects harboured significantly higher levels and/or proportion of Porphyromonas gingivalis, Tannerella forsythia (levels: p<0.001, proportion: p<0.01), Prevotella nigrescens (p<0.05 levels) and "red" complex species (p<0.001 proportion) than PH subjects. All GAgP subjects were carriers of P. gingivalis and P. nigrescens. No significant differences in any of the 40 microbial species tested were detected between GAgP and GCP subjects. CONCLUSIONS: Our results revealed that the microbial differences between GAgP and GCP subjects were only discrete and none of the bacterial species tested seemed to specifically differentiate the subgingival microbial profile of either periodontitis group.     

Subgingival microflora in Turkish patients with periodontitis

BACKGROUND: No information exists on periodontitis-associated subgingival microbiota from Turkey. We determined the occurrence, interspecies relationships, and clonal characteristics for a group of periodontal bacteria in a Turkish study population. METHODS: Subgingival microbial samples were obtained from patients with localized (LAgP, N = 18) or generalized (GAgP, N = 17) types of aggressive periodontitis, generalized chronic periodontitis (GCP, N = 14), and non-periodontitis subjects (N = 20). Culture methods were used to recover 6 periodontal bacterial species and yeasts, and a polymerase chain reaction technique was used to detect Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Intraspecies characterization of A. actinomycetemcomitans was carried out by serotyping and genotyping. RESULTS: All species, except for Micromonas micros (formerly Peptostreptococcus micros) occurred more frequently (P < 0.05) in periodontitis than non-periodontitis subjects. Detection frequencies for Tannerella forsythensis (formerly Bacteroides forsythus) and Campylobacter rectus differed among the periodontitis subgroups; the lowest frequency occurred in LAgP. The mean proportions of A. actinomycetemcomitans, P. gingivalis, and C. rectus were higher (P < 0.008) in GAgP than in non-periodontitis subjects. Significant positive associations were seen between 7 of the 22 possible combinations (P < 0.05). A. actinomycetemcomitans serotype c (34%) and non-serotypeable isolates (34%) were the most common antigenic types among the 305 strains analyzed. Eleven arbitrarily primed (AP)-PCR genotypes were distinguished among 273 isolates from 29 subjects. Yeasts were found in 23% of the 69 subjects. CONCLUSIONS: The results on the Turkish study population were generally in line with earlier reports on the occurrence and interspecies relationships of certain bacteria in periodontitis. However, A. actinomycetemcomitans was not overrepresented in LAgP, and the serotype distribution resembled that reported from the East. The high frequency of non-serotypeable isolates suggests local characteristics of the species.     

2型糖尿病患者慢性牙周炎细菌学研究

目的 :研究 2型糖尿病患者慢性牙周炎的龈下菌群以及菌群变化与血糖、糖化血红蛋白的关系。方法 :细菌学厌氧培养、PCR检测技术。结果 :2型糖尿病患者慢性牙周炎的龈下菌群以厌氧菌为主。产黑菌、二氧化碳噬纤维菌数量与糖尿病患者空腹血糖、糖化血红蛋白之间存在正相关关系。产黑菌、二氧化碳噬纤维菌数量随患者空腹血糖、糖化血红蛋白的升高而增加。结论 :2型糖尿病慢性牙周炎患者龈下菌斑相关菌与血糖、糖化血红蛋白变化密切相关     

Subgingival microbiota in healthy, well-maintained elder and periodontitis subjects

Abstract. This investigation compared the site prevalence of 40 subgingival species in 30 periodontally healthy (mean age 36±9 years). 35 elders with a well-maintained periodontium (mean age 77±5) and 138 adult periodontitis subjects (mean age 46± 11). Subgingival plaque samples were taken from the mesial aspect of each tooth (up to 28 samples) in the 203 subjects at baseline. The presence and levels of 40 subgingival taxa were determined in 5003 plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments including dichotomous measures of gingival redness, bleeding on probing, plaque accumulation and suppuration, as well as duplicate measures of pocket depth and attachment level, were made at 6 sites per tooth. The % of sites colonized by each species (prevalence) was computed for each subject. Differences in prevalence and levels among groups were sought using the Kruskal-Wallis test. Commonly detected species, such as Actinomyces naeslundii genospecies 2, Streptococcus sanguis and Streptococcus oralis did not differ significantly among subject groups. After adjusting for multiple comparisons, 4 species were significantly elevated and at greater prevalence in the periodontitis group. Mean % of sites (±SEM) colonized by Bacteroides forsythus was 10±3, 12±2 and 40±2 (p<0.001) for healthy, elder and periodontitis groups respectively. The odds ratio was 14.4:1 that a subject had periodontitis when B. forsythus was detected at ≥5% of sampled sites. Mean prevalence for Porphyromonas gingivalis in healthy, elder and periodontitis subjects was 4±2, 5±2 and 23±2 respectively (p<0.001); for Treponema denticola 12±4, 10±3 and 30±2 (p<0.001) and for Selenomonas noxia 6±2, 7±2 and 19±2 (p<0.01). Similar differences among subject groups were observed when only sites with PD 0-4 mm were analyzed. The data suggest an etiologic role for B. forsythus, P. gingivalis, T. denticola and S. noxia in adult periodontitis.     

慢性牙周炎患者的龈下微生物与吸烟状况

目的　评价慢性牙周炎患者的吸烟状况与龈下牙周致病微生物的百分比。方法　 112例慢性牙周炎患者 ,根据吸烟状况分为 :①重度吸烟组 >10支 /天 (n =32 ) ;②轻度吸烟组≤ 10支 /天 (n =18) ;③戒烟者组 (n =2 4 ) ;④非吸烟组 (n =38)。观察者口内每个象限 ,选取探诊最深的 1或 2个位点 ,纸捻法取龈下菌斑 ,厌氧培养 ;并测量该位点的探诊深度 (ProbeDepth ,PD)、附着丧失 (AttachmentLoss,AL)和探诊后出血 (Bleedingofprobe ,BOP)。结果　①取样位点临床指标的均值为PD :6 .3mm、AL :6 .5mm及BOP :89% ,各组间无显著性差异。②组间菌落形成单位和龈下微生物伴放线放线杆菌 (Actinobacillusactinomycetemcomitans,A .a)、牙龈卟啉单胞菌 (Porphyromanasgingivalis,P .g)、中间普氏菌 (Prevotellaintermedia ,P .i)、核梭杆菌 (Fusobacteriumnucleatum ,F .n)和微消化球菌(Peptostreptococcusmicros,P .m)的百分比均无差异。③方差分析显示仅轻度吸烟组福赛类杆菌 (Bacteroidesforsythus,B .f)的百分比略高于其它组 (P <0 .0 4 )。结论　慢性牙周炎患者 ,探诊深度和附着丧失相似的位点 ,吸烟组、戒烟组和非吸烟组的龈下牙周致病微生物百分比 (B .f除外 )无显著差异。     

Subgingival plaque microbiota in HIV positive patients

AIM: To describe and compare the predominant bacterial and fungal species associated with gingivitis, periodontitis, and linear gingival erythema (LGE), in HIV positive subjects with different immune status. METHODS: Viral loads and CD4 levels determined HIV disease status. From pooled subgingival plaque, 16S and 18S rDNA were cloned and sequenced to determine species identity. RESULTS: One hundred and nine bacterial species were identified from 14 subjects. Nearly half of the species were not cultivable. Notably, the classical putative periodontal pathogens, Treponema denticola, Porphyromonas gingivalis and Tannerella forsythia were below the limit of detection and were not detected. Species of Gemella, Dialister, Streptococcus and Veillonella were predominant. In one HIV positive subject with periodontitis and low viral load, Gemella morbillorum, a known opportunistic pathogen, constituted 84% of the clones. Saccharomyces cerevisiae was the only fungal species detected in an LGE subject and in periodontitis subjects with high viral loads. In periodontitis patients with low viral loads, Candida albicans was predominant, while S. cerevisiae was only a minor component. CONCLUSION: These case studies suggest that other bacterial species, rather than the classical periodontal pathogens, may be involved in periodontal diseases of subjects with HIV. These data are indicative of opportunistic infections in a highly susceptible immunocompromised host.     

Subgingival microbial profiles in chronic periodontitis patients from Chile, Colombia and Spain

Aim: To investigate the subgingival microbiota of distinct periodontitis patient populations, in Chile, Colombia and Spain, using identical clinical and bacteriological methods. Material and Methods: In this multicentre study, 114 chronic periodontitis patients were selected. Patients were examined using an identical clinical protocol and pooled subgingival samples were obtained from each patient. Samples were processed in the three laboratories by means of culturing under identical clinical and microbiological protocols. Total anaerobic counts and frequency of detection and proportions of nine periodontal pathogens were calculated. Variables were analysed by means of anova , χ², Kruskal–Wallis and Dunn's multiple comparison tests. Results: The Colombian population demonstrated greater severity of periodontitis, with significantly deeper mean probing pocket depth, and had a significantly lower percentage of current smokers. When comparing samples from the three patient populations, the total counts were significantly higher in the Colombian patients. The numbers of putative pathogens differed among groups. Tannerella forsythia was found less frequently in Chilean samples, while Parvimonas micra and enteric rods differed significantly among the three population groups. Conclusion: Significant differences among Chile, Colombia and Spain existed regarding the frequency and proportions of specific periodontal pathogens in the subgingival microbiota of periodontitis patients.     

Subgingival microflora and periodontitis

Predominant bacterial flora resident in subgingival plaque was characterized and evaluated in relation to the etiology of periodontal disease. Small groups of clinically and radiographically identified periodontal patients and control subjects were studied. A comprehensive inventory of cultivable flora was made. The most common group of organisms were the Gram-positive rods, the majority of which were Actinomyces . A larger proportion of anaerobic Gram-negative rods were isolated than indicated in the results of previous studies. Considerable variability in floral content was found in different sites in the same patient. However, no statistically significant differences were observed in the flora between clinically normal and pathological sites of the same patients. A significantly greater number of facultative Actinomyces was present in the flora of periodontal patients as compared to control subjects.
Sera from the same nine subjects were assayed by indirect immunofluorescence for circulating antibodies to 12 strains of plaque bacteria. No differences in antibody titers were observed between sera from periodontal patients and control subjects.     

Subgingival microflora and treatment in prepubertal periodontitis associated with chronic idiopathic neutropenia

Abstract. Prepubertal periodontitis affects both primary and permanent dentition. The purpose of this study was to examine the composition of subgingival microflora of the permanent dentition in an 11-year-old Caucasian female, who had premature exfoliation of her deciduous teeth on her 5th year of age, and the response of this condition to the antibiotic therapy and supportive periodontal care. Gingival tissues were highly inflamed and alveolar bone loss was detected radiographically. The girl had experienced frequent upper respiratory tract infections, tonsilitis and recurrent otitis media. Her mother had history of early onset periodontitis associated with chronic idiopathic neutropenia. Blood chemistry tests and immunological examinations were also performed. Subgingival plaque samples were collected from the proximal sites of permanent molars, incisors, canines and maxillary premolars. 27 different microbial species were isolated from the subgingival microflora. Among the predominant species were Porphyromonas gingivalis (17.6%-7.3%), Prevotella intertnedia (12.4%-4.7%), Capnocytophaga sputigena (14.4%-10.4%), Capnocytophaga ochracea (13.2%-6.9%) and Actinobacillus actinomycetemcomitans (9.3%-5.5%.). Periodontal treatment consisted of scaling, root planing in conjunction with antibiotic administration of Augmentin® 312.5 mg and Flagyl® 200 mg, each t.i.d. for 10 days. 3 weeks after the antibiotic therapy, bacterial samples were collected from the same sites. All the periodontal pathogens were recovered in lower levels and A. actinomycetemcomitans was almost eliminated in the 3-week period. The evaluation of clinical indices at 3, 6 and 12 months showed that periodontal treatment in conjunction with antibiotics was effective and rapidly followed by marked clinical improvement. The microbiological monitoring at 3, 6 and 12 months after antibiotic treatment and each time prior to supportive periodontal care, revealed that the periodontal pathogens fluctuated in low levels even 12 months after treatment and could be maintained at low level by supportive periodontal care at 3-month intervals.     

Subgingival microbiome in smokers and non‐smokers in Korean chronic periodontitis patients

Smoking is a major environmental factor associated with periodontal diseases. However, we still have a very limited understanding of the relationship between smoking and subgingival microflora in the global population. Here, we investigated the composition of subgingival bacterial communities from the pooled plaque samples of smokers and non‐smokers, 134 samples in each group, in Korean patients with moderate chronic periodontitis using 16S rRNA gene‐based pyrosequencing. A total of 17,927 reads were analyzed and classified into 12 phyla, 126 genera, and 394 species. Differences in bacterial communities between smokers and non‐smokers were examined at all phylogenetic levels. The genera Fusobacterium, Fretibacterium, Streptococcus, Veillonella, Corynebacterium, TM7, and Filifactor were abundant in smokers. On the other hand, Prevotella, Campylobacter, Aggregatibacter, Veillonellaceae GQ422718, Haemophilus, and Prevotellaceae were less abundant in smokers. Among species‐level taxa occupying > 1% of whole subgingival microbiome of smokers, higher abundance (≥ 2.0‐fold compared to non‐smokers) of seven species or operational taxonomic units (OTUs) was found: Fusobacterium nucleatum, Neisseria sicca, Neisseria oralis, Corynebacterium matruchotii, Veillonella dispar, Filifactor alocis, and Fretibacterium AY349371. On the other hand, lower abundance of 11 species or OTUs was found in smokers: Neisseria elongata, six Prevotella species or OTUs, Fusobacterium canifelinum, Aggregatibacter AM420165, Selenomonas OTU, and Veillonellaceae GU470897. Species richness and evenness were similar between the groups whereas diversity was greater in smokers than non‐smokers. Collectively, the results of the present study indicate that differences exist in the subgingival bacterial community between smoker and non‐smoker patients with chronic moderate periodontitis in Korea, suggesting that cigarette smoking considerably affects subgingival bacterial ecology.     

Subgingival biodiversity in subjects with uncontrolled type‐2 diabetes and chronic periodontitis

Background and Objective: There is a bidirectional relationship between periodontal disease and type‐2 diabetes mellitus (DM). Inflammatory mediators may negatively affect glycemic control, and increased glucose levels and resultant glycation end‐products may alter the host response against bacterial infection. However, no agreement has been reached regarding the effect of DM on periodontal subgingival microbiota. Therefore, the purpose of the present study was to compare the subgingival biodiversity in deep periodontal pockets of subjects with chronic periodontitis and either uncontrolled type‐2 diabetes or no diabetes using 16S rRNA gene cloning and sequencing. Material and methods: Twelve subjects with uncontrolled type‐2 diabetes (glycated hemoglobin > 8%) and eleven nondiabetic subjects presenting severe and generalized chronic periodontitis were selected. Subgingival biofilm from periodontal pockets > 5 mm were assessed using the 16S rRNA gene cloning and sequencing technique. Results: Significant differences were observed in subgingival microbiota between diabetic and nondiabetic subjects. Diabetic subjects presented higher percentages of total clones of TM7, Aggregatibacter, Neisseria, Gemella, Eikenella, Selenomonas, Actinomyces, Capnocytophaga, Fusobacterium, Veillonella and Streptococcus genera, and lower percentages of Porphyromonas, Filifactor, Eubacterium, Synergistetes, Tannerella and Treponema genera than nondiabetic individuals (p < 0.05). Moreover, some phylotypes, such as Fusobacterium nucleatum, Veillonella parvula, V. dispar and Eikenella corrodens were detected significantly more often in diabetic subjects than in nondiabetic subjects (p < 0.05). Conclusion: Subjects with uncontrolled type‐2 diabetes and chronic periodontitis presented significant dissimilarities in subgingival biodiversity compared with nondiabetic subjects.     

Subgingival microbiota of renal transplant recipients

Renal transplant patients undergoing immunosuppressive therapy may experience periodontal side-effects such as gingival overgrowth. This study evaluated the subgingival microbiota of renal transplant recipients with or without periodontal tissue destruction who may have concurrent gingival enlargement. Subgingival paper point samples taken from the deepest probing sites of 38 subjects (one per patient) were examined using direct microscopy and culture techniques. A complex microflora comprising gram-positive and gram-negative cocci, rods and filaments, fusiforms, curved rods and spirochetes was observed using microscopy. Yeasts were occasionally detected. Significantly higher proportions of gram-positive morphotypes, including gram-positive cocci, were observed in samples from periodontally healthy patients. The predominant cultivable microflora from anaerobic culture comprised several species of facultative and obligate anaerobes. Colonization of the subgingival sites by 'foreign' microbes that are normally dermal, intestinal or vaginal flora was detected in up to 50% of the samples. High mean proportions of lost or unidentified species were also occasionally noted. The results showed that the subgingival biofilm of renal transplant recipients with chronic periodontitis comprised mainly gram-negative rods and spirochetes. Besides the usual predominant cultivable subgingival microbiota associated with periodontitis, the high prevalence of unidentified and 'foreign' microbes indicates the possibility of subgingival microbial alteration in renal transplant patients.