Age and sex relationships of superinfecting microorganisms in periodontitis patients

Interactions between systemic diseases and oral microbiota shifts in the aging community: A narrative review

As a gateway to general health and a diverse microbial habitat, the oral cavity is colonized by numerous microorganisms such as bacteria, fungi, viruses, and archaea. Oral microbiota plays an essential role in preserving oral health. Besides, the oral cavity also significantly contributes to systemic health. Physiological aging influences all body systems, including the oral microbial inhabitants. The cited effect can cause diseases by forming dysbiotic communities. Since it has been demonstrated that microbial dysbiosis could disturb the symbiosis state between the host and the resident microorganism, shifting the condition toward a more pathogenic one, this study investigated how the oral microbial shifts in aging could associate with the development or progression of systemic diseases in older adults. The current study focused on the interactions between variations in the oral microbiome and prevalent diseases in older adults, including diabetes mellitus, Sjögren's syndrome, rheumatoid arthritis, pulmonary diseases, cardiovascular diseases, oral candidiasis, Parkinson's disease, Alzheimer's disease, and glaucoma. Underlying diseases can dynamically modify the oral ecology and the composition of its resident oral microbiome. Clinical, experimental, and epidemiological research suggests the associations of systemic disorders with bacteremia and inflammation after oral microbial changes in older adults.

Periodontal microorganisms and Alzheimer disease - A causative relationship?

In the initiation or exacerbation of Alzheimer disease, the dissemination of oral microorganisms into the brain tissue or the low‐level systemic inflammation have been speculated to play a role. However, the impact of oral microorganisms, such as Porphyromonas gingivalis, on the pathogenesis of Alzheimer disease and the potential causative relationship is still unclear. The present review has critically reviewed the literature by examining the following aspects: (a) the oral microbiome and the immune response in the elderly population, (b) human studies on the association between periodontal and gut microorganisms and Alzheimer disease, (c) animal and in vitro studies on microorganisms and Alzheimer disease, and (d) preventive and therapeutic approaches. Factors contributing to microbial dysbiosis seem to be aging, local inflammation, systemic diseases, wearing of dentures, living in nursing homes and no access to adequate oral hygiene measures. Porphyromonas gingivalis was detectable in post‐mortem brain samples. Microbiome analyses of saliva samples or oral biofilms showed a decreased microbial diversity and a different composition in Alzheimer disease compared to cognitively healthy subjects. Many in‐vitro and animal studies underline the potential of P gingivalis to induce Alzheimer disease‐related alterations. In animal models, recurring applications of P gingivalis or its components increased pro‐inflammatory mediators and β‐amyloid in the brain and deteriorated the animals' cognitive performance. Since periodontitis is the result of a disturbed microbial homoeostasis, an effect of periodontal therapy on the oral microbiome and host response related to cognitive parameters may be suggested and should be elucidated in further clinical trials.

Integrative multiomics analysis reveals host-microbe-metabolite interplays associated with the aging process in Singaporeans

The age-associated alterations in microbiomes vary across populations due to the influence of genetics and lifestyles. To the best of our knowledge, the microbial changes associated with aging have not yet been investigated in Singapore adults. We conducted shotgun metagenomic sequencing of fecal and saliva samples, as well as fecal metabolomics to characterize the gut and oral microbial communities of 62 healthy adult male Singaporeans, including 32 young subjects (age, 23.1 ± 1.4 years) and 30 elderly subjects (age, 69.0 ± 3.5 years). We identified 8 gut and 13 oral species that were differentially abundant in elderly compared to young subjects. By combining the gut and oral microbiomes, 25 age-associated oral-gut species connections were identified. Moreover, oral bacteria Acidaminococcus intestine and Flavonifractor plautii were less prevalent/abundant in elderly gut samples than in young gut samples, whereas Collinsella aerofaciens and Roseburia hominis showed the opposite trends. These results indicate the varied gut-oral communications with aging. Subsequently, we expanded the association studies on microbiome, metabolome and host phenotypic parameters. In particular, Eubacterium eligens increased in elderly compared to young subjects, and was positively correlated with triglycerides, which implies that the potential role of E. eligens in lipid metabolism is altered during the aging process. Our results demonstrated aging-associated changes in the gut and oral microbiomes, as well as the connections between metabolites and host-microbe interactions, thereby deepening the understanding of alterations in the human microbiome during the aging process in a Singapore population.

Microbiology of periodontal disease in adolescents with Type 1 diabetes

BACKGROUND AND AIMS

Diabetes and periodontal disease are chronic disorders with complex interplay. Periodontal microbiota may play a major role in the development of periodontal disease (PD). The study was framed to identify oral microorganisms and assess oral biofilm in children & adolescents with T1DM and PD.

METHODS

In this cross-sectional study we recruited a total of 60 subjects aged 10-18 years (in 3 groups of 20 each). Group 1: Diabetes with periodontal disease (DMPD), Group 2: Diabetes without periodontal disease (DM), Group 3: Periodontal disease without Diabetes (PD).Gingival plaque samples were collected and processed for culture based microbial identification and biofilm assay.

RESULTS

The microbial diversity in the DMPD group was higher. Staphylococcus warneri was the only organism specifically isolated from DMPD group. Staphylococcus vitulinus, Streptococcus sanguinis, Pseudomonas aeruginosa, was commonly isolated from both DMPD and PD group especially higher incidence in DMPD group (P ≤ 0.001).There was a strong positive correlation between poor glycaemic control and biofilm formation in both Groups 1 & 2 (DMPD and DM) patients (Spearman's Rho: 0.868, P < 0.001).

CONCLUSION

Children & adolescents with T1DM with worse glycaemic control, associated with higher abundance of biofilm formation and greater microbial diversity, especially in those with T1DM with PD.

Comparative Analyses of the Subgingival Microbiome in Chronic Periodontitis Patients with and without Gingival Erosive Oral Lichen Planus Based on 16S rRNA Gene Sequencing

The aim of the study was to compare the microbiota composition and bacterial diversity of subgingival plaque in chronic periodontitis patients with and without gingival erosive oral lichen planus. The subgingival plaque samples of 20 chronic periodontitis patients with gingival erosive oral lichen planus (CP-OLP group) and 19 chronic periodontitis patients without gingival erosive oral lichen planus (CP group) were analyzed by 16S rRNA gene high-throughput sequencing. Compared with the CP group, the richness and diversity of subgingival plaque microflora in the CP-OLP group decreased significantly. There were some differences between the two groups in the composition of microflora on the levels of phylum and genus. Distributions of Prevotella and Leptotrichia in the CP-OLP group were significantly lower than those in the CP group. The dominant genera in CP-OLP group were Pseudomonas and Granulicatella. These results indicated that gingival erosive oral lichen planus may influence the structure and proportion of subgingival plaque microflora.

Microbiome succession with increasing age in three oral sites

The incidence of oral diseases is remarkably increased with age, and it may be related to oral microbiota. In this study, we systematically investigated the microbiota of gingival crevicular fluid (GCF), tongue back (TB) and saliva (SAL) from various age groups in healthy populations. The microbial diversity results indicated that the α-diversity of bacteria had a tendency to decrease in aging mouth, whereas the β-diversity showed an opposite increasing trend in all three sites. Next, the microbial structure exploration revealed a divergence in bacterial profile in three sites in response to aging, but the intersite differential bacteria demonstrated a uniform bell-shaped variation trend with age. Meanwhile, several age-differentiated genera were shared by GCF, SAL and TB sites, and the bacterial correlation analysis demonstrated a clear shift in the pattern of bacterial correlations with age. Moreover, both the intra- and intersite "core microbiome" showed significantly decreased bacterial diversities with age. Finally, the trending differential bacteria species were used as a biomarker to distinguish the different age groups, and the prediction accuracies in GCF were 0.998, 0.809, 0.668, 0.675 and 0.956. Our results revealed the characteristics of intra- and intersite bacterial succession with age, providing novel insights into senile oral diseases.

Applications of the oral microbiome in personalized dentistry

OBJECTIVE

In the era of personalized medicine, it is imperative that oral health is integrated into this concept. The oral cavity fosters a highly individualized microbiome that has evolved to promote oral health, and which exists in a dynamic balance with the host. Microecological changes to the biology of the mouth [e.g. in the host diet and lifestyle, or status of the immune system] may drive deleterious shifts in the composition or metabolic activity of the oral microbiome ['dysbiosis']. This review aims to explore how knowledge of the oral microbiome may be utilized for personalized dentistry at the point-of-care.

DESIGN

This is a comprehensive narrative review of the literature, summarizing the perspectives of the authors.

RESULTS

The huge increase in recent knowledge on the ecology and microbiology of the oral cavity generated by 'OMIC' technologies may indeed be clinically translated to support patient care, in terms of prevention, monitoring, risk classification or early diagnosis. The identified clinical applications may not only include dental caries and periodontal disease, but also dental implants and orthodontics. Population-based applications may include systemic health, pregnancy and elderly populations.

CONCLUSIONS

Applications of selected oral microbiome and host-related biochemical parameters [e.g. the saliva proteome] for personalized dentistry can be customized for different clinical applications or individual populations, at point-of-care hubs.

Microbiological changes of the ageing oral cavity

OBJECTIVE

Ageing is a physiological process that affects virtually all systems of the human body. Age-associated changes in the oral cavity reflect changes in the composition of its microbial inhabitants, which can be compatible with health or form dysbiotic communities that favor the establishment of disease. This paper focuses on discussing such age-driven changes of the oral microbiome, as well as their association with common oral infectious diseases, including dental caries, periodontitis, peri-implantitis and oral candidiasis.

DESIGN

This is a comprehensive narrative review of the literature.

RESULTS

The oropharyngeal microbiome of elderly individuals may foster a number of microorganisms such as enterobacteria, pseudomonads, staphylococci and yeasts that can become opportunistic pathogens in elderly individuals with weakened immunity or deteriorated general health. No considerable microbiological variations are noted with regards to common oral diseases, such as dental caries and periodontitis, between younger and elderly populations, whereas an increase in the prevalence of oral actinomycetes is noted by ageing.

CONCLUSIONS

Whether naturally occurring or driven by underlying disease, the ecology of oral cavity is dynamically modified over time, eliciting changes in the composition of the resident oral microbiome.

The subgingival periodontal microbiota of the aging mouth

Different mechanisms have been hypothesized to explain the increase in prevalence and severity of periodontitis in older adults, including shifts in the periodontal microbiota. However, the actual impact of aging on the composition of subgingival biofilms remains unclear. In the present article, we provide an overview of the composition of the subgingival biofilm in older adults and the potential effects of age on the oral microbiome. In particular, this review covers the following topics: (i) the oral microbiota of an aging mouth; (ii) the effects of age and time on the human oral microbiome; (iii) the potential impact of inflammaging and immunosenescence in the host-oral microbiota interactions; and (iv) the relationship of the aging oral microbiota and Alzheimer's disease. Finally, we present analyses of data compiled from large clinical studies that evaluated the subgingival microbiota of periodontally healthy subjects and patients with periodontitis from a wide age spectrum (20-83 years of age).

Effect of cigarette smoking on subgingival bacteria in healthy subjects and patients with chronic periodontitis

Background

Cigarette smoking is known to increase the risk of periodontal destruction and developing chronic periodontitis (CP). It is also reported to affect the subgingival bacterial profile among CP patients. However, studies on the effect of smoking on the bacterial profile among healthy subjects are still limited. Therefore, the aim of this study was to investigate the impact of smoking on the subgingival bacterial profile in both healthy adults and CP patients.

Methods

Subgingival plaque samples were collected from CP patients (30 nonsmokers and 9 smokers) and healthy subjects (37 non-smokers and 18 smokers). Genomic DNA was extracted and 25 bacterial species were detected using PCR of 16S rRNA. Comparing smokers to non-smokers from each group was conducted using chi2 and binary logistic regression analysis.

Results

After correcting for confounding factors, the odds of having Slackia exigua, Selenomonas sputigena and Campylobacter rectus was higher among healthy smokers (ORadj = 10.1, 6.62 and 5.62 respectively). While for CP group, the highest odds were observed for Treponema amylovorum, Treponema medium, Slackia exigua and Treponema vincentii (ORadj = 20.7, 7.97, 6.37 and 5.37 respectively) and the increase in Treponema amylovorum was statistically significant (p = 0.05).

Conclusion

Smoking affects the subgingival bacterial profile in healthy individuals and is responsible for the depletion of beneficial bacteria and the increase in periodontopathogenic bacteria. In the CP patient group, our study suggests that subgingival bacteria (particularly Treponema species) make a more substantial contribution in the etiology of CP among non-smokers. Further studies using a larger sample set and more sensitive and quantitative techniques (such as real -time PCR) are needed to enhance our understanding of the exact effect of smoking on subgingival biofilm.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-017-0359-4) contains supplementary material, which is available to authorized users.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Prevalence of subgingival Staphylococcus at periodontally healthy and diseased sites

Staphylococci are considered members of the transient oral microbiota and are seldom isolated from the oral cavity. The aim of this study was to establish the prevalence of subgingival staphylococci in healthy and periodontal disease sites. Sterile endodontic paper points were used to isolate subgingival staphylococci in periodontally healthy and periodontally diseased sites in 30 adult subjects (n=540 sites). Staphylococcus spp were identified by an automated method and confirmed by conventional biochemical tests. All the samples were identified as coagulase-negative staphylococci. The results were analyzed using Mann-Whitney U, chi-square and Fisher's exact test at 5% significance level. A total of 86.7% of the subjects harbored these microorganisms in 11.7% of their periodontal sites. The most frequently isolated species was S. auricularis, which was isolated from 31.4% of the periodontal sites, followed by S. epidermidis, isolated from 21.4% of them. There was no statistically significant difference between the frequencies of these species isolated either from the healthy and the diseased sites (p>0.153). Although staphylococci are present in the subgingival environment and contribute to the pathogenic synergism involved in periodontal diseases, the results suggest that they do not participate directly in the pathogenesis of these diseases.

Microbial diversity in individuals and their household contacts following typical antibiotic courses

BACKGROUND

Antibiotics are a mainstay of treatment for bacterial infections worldwide, yet the effects of typical antibiotic prescriptions on human indigenous microbiota have not been thoroughly evaluated. We examined the effects of the two most commonly prescribed antibiotics (amoxicillin and azithromycin) in the USA to discern whether short-term antibiotic courses may have prolonged effects on human microbiota.

RESULTS

We sampled the feces, saliva, and skin specimens from a cohort of unrelated, cohabitating individuals over 6 months. An individual in each household was given an antibiotic, and the other a placebo to discern antibiotic impacts on microbiota, as well as determine whether antibiotic use might reshape the microbiota of each household. We observed household-specific patterns of microbiota on each body surface, which persevered despite antibiotic perturbations. While the gut microbiota within an individual became more dissimilar over time, there was no evidence that the use of antibiotics accelerated this process when compared to household members. There was a significant change in microbiota diversity in the gut and mouth in response to antibiotics, but analogous patterns were not observed on the skin. Those who received 7 days of amoxicillin generally had greater reductions in diversity compared to those who received 3 days, in contrast to those who received azithromycin.

CONCLUSIONS

As few as 3 days of treatment with the most commonly prescribed antibiotics can result in sustained reductions in microbiota diversity, which could have implications for the maintenance of human health and resilience to disease.

Human oral viruses are personal, persistent and gender-consistent

Viruses are the most abundant members of the human oral microbiome, yet relatively little is known about their biodiversity in humans. To improve our understanding of the DNA viruses that inhabit the human oral cavity, we examined saliva from a cohort of eight unrelated subjects over a 60-day period. Each subject was examined at 11 time points to characterize longitudinal differences in human oral viruses. Our primary goals were to determine whether oral viruses were specific to individuals and whether viral genotypes persisted over time. We found a subset of homologous viral genotypes across all subjects and time points studied, suggesting that certain genotypes may be ubiquitous among healthy human subjects. We also found significant associations between viral genotypes and individual subjects, indicating that viruses are a highly personalized feature of the healthy human oral microbiome. Many of these oral viruses were not transient members of the oral ecosystem, as demonstrated by the persistence of certain viruses throughout the entire 60-day study period. As has previously been demonstrated for bacteria and fungi, membership in the oral viral community was significantly associated with the sex of each subject. Similar characteristics of personalized, sex-specific microflora could not be identified for oral bacterial communities based on 16S rRNA. Our findings that many viruses are stable and individual-specific members of the oral ecosystem suggest that viruses have an important role in the human oral ecosystem.

Low-cost periodontal therapy

Periodontitis is a complex infectious disease that affects low-income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low-cost periodontal therapy that involves professional and patient-administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone-iodine and sodium hypochlorite have all the characteristics for becoming the first-choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin-metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle-aged patients, and ciprofloxacin-metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients.

Relationship between Gram negative enteric rods, Aggregatibacter actinomycetemcomitans, and clinical parameters in periodontal disease

BACKGROUND

The association between Gram negative enteric rods and Aggregatibacter actinomycetemcomitans in periodontal diseases has received little attention in the literature. The objective of this study was to explore the relationship between these organisms and clinical parameters of periodontal disease.

MATERIALS AND METHODS

Clinical parameters and occurrence of Gram-negative enteric rods and A. actinomycetemcomitans were examined in 76 patients with chronic periodontitis. Chi-square and Mann-Whitney tests were used to determine differences in clinical variables versus the presence or absence of both microorganisms. Correlation among both organisms and clinical data were determined using Spearman rank correlation coefficient.

RESULTS

Gram-negative enteric rods and A. actinomycetemcomitans were detected in 20 (26.3%) and 18 (23.7%) individuals, respectively. A total of 14 (18.4%) patients harbored both microorganisms studied. There were significantly positive correlations between enteric rods and presence of A. actinomycetemcomitans (r=0.652, P<0.0001). Both microorganisms were significant and positively correlated with probing depth (PD), clinical attachment level, and bleeding on probing (P<0.0001). The mean PD (mm) of the sampled sites was significantly deeper in patients with presence of A. actinomycetemcomitans and Gram-negative enteric rods.

CONCLUSION

The results of the present study suggest a strong positive correlation between Gram-negative enteric rods and A. actinomycetemcomitans in the population studied. This finding must be taken into account when considering the best therapeutic approach, including the utilization of antimicrobials. The adverse clinical outcomes observed in presence of these microorganisms could have implications in the pathogenesis of periodontal disease and a possible impact on outcomes after treatment.

Fabrication and anti-microbial evaluation of drug loaded polylactide space filler intended for ridge preservation following tooth extraction

Background:

The preservation or reduction of alveolar ridge resorption following tooth extraction is important in patients especially for those intended for implants at a later stage. One way to achieve this is by using membranes, graft materials, and biodegradable space fillers to prevent alveolar bone resorption and promote regeneration. A major attraction for using biodegradable and biocompatible polymers as space fillers for ridge preservation is their safety profile in comparison to xenograft materials like lyophilized bone and collagen.

Materials and Methods:

Biocompatible polylactide space fillers were fabricated by fusing porous polylactide particles. The sponges were loaded with drugs by placing them in the respective solutions. Pseudomonas aeruginosa was isolated from a chronic periodontitis patient and in vitro anti-microbial evaluation was done with the drug loaded sponges.

Results:

Chlorhexidine loaded space filler showed significant anti microbial effect against multiple drug resistant Pseudomonas aeruginosa isolated from a patient with chronic periodontitis.

Conclusion:

The results of this study indicate that biodegradable drug releasing polylactide space fillers has the potential to be used for ridge preservation following tooth extraction. Release of drugs in the socket may prove useful in preventing development of alveolar osteitis post extraction which can interfere with normal healing of the socket. Synthetic biodegradable polymers also exhibit a controlled degradation rate to achieve complete resorption within the intended time.

Microbiological and immunological characteristics of young Moroccan patients with aggressive periodontitis with and without detectable Aggregatibacter actinomycetemcomitans JP2 infection

Cross-sectional and longitudinal studies identify the JP2 clone of Aggregatibacter actinomycetemcomitans as an aetiological agent of aggressive periodontitis (AgP) in adolescents of northwest African descent. To gain information on why a significant part of Moroccan adolescents show clinical signs of periodontal disease in the absence of this pathogen we performed comprehensive mapping of the subgingival microbiota of eight young Moroccans, four of whom were diagnosed with clinical signs of AgP. The analysis was carried out by sequencing and phylogenetic analysis of a total of 2717 cloned polymerase chain reaction amplicons of the phylogenetically informative 16S ribosomal RNA gene. The analyses revealed a total of 173 bacterial taxa of which 39% were previously undetected. The JP2 clone constituted a minor proportion of the complex subgingival microbiota in patients with active disease. Rather than identifying alternative aetiologies to AgP, the recorded infection history of the subjects combined with remarkably high concentrations of antibodies against the A. actinomycetemcomitans leukotoxin suggest that disease activity was terminated in some patients with AgP as a result of elimination of the JP2 clone. This study provides information on the microbial context of the JP2 clone activity in a JP2-susceptible population and suggests that such individuals may develop immunity to AgP.

Yeast diversity in the oral microbiota of subjects with periodontitis: Candida albicans and Candida dubliniensis colonize the periodontal pockets

The term periodontitis encompasses several polymicrobial infectious diseases, of multifactorial etiology, with chronic and aggressive forms. In spite of the etiopathogenic differences between these two forms of the disease, few studies have analyzed the subgingival colonization by yeast. The objective of this investigation was to analyze the composition of the yeast microbiota present in the mucosa and subgingival sites of healthy individuals and patients with aggressive and chronic periodontitis. For this, samples were recovered from these two locations and the yeast recovered identified by phenotypic and genotypic methods. Patients with chronic periodontitis showed significant differences in relation to the other groups with respect to carrier status (69.2% versus 35.7% of healthy individuals; [chi(i)(2) test; p=0.014]), the total number of isolated colony forming units or CFU (mean and ranges 281.6 (0-6048) [K-W(2)=6.998; p=0.03]), the Simpson diversity index (I) in site b (I(b)=0.344 versus healthy subjet and aggresive periodontitis where I=0 [multiple t-test comparisons with the Bonferronni correction, p<0.05]), and the species profile. Interestingly, in spite of the varied profiles of the species present in the mucosa of the three groups analyzed we noted that only C. albicans and C. dubliniensis were capable of colonizing the periodontal pockets in patients with chronic periodontitis, while only C. albicans was identified in the subgingiva of healthy individuals and patients with aggressive periodontitis.

Occurrence of Periodontopathic and Superinfecting Bacteria in Chronic and Aggressive Periodontitis Subjects in a Colombian Population

BACKGROUND

Differences in the composition of subgingival microbiota in periodontitis have been observed in different geographic locations. Some of these microbial differences could have clinical significance. This study describes clinical parameters and the composition of the subgingival microbiota in chronic periodontitis (CP) and aggressive periodontitis (AgP) patients in a Colombian population.

METHODS

Clinical parameters (probing depth, clinical attachment level, bleeding on probing, and plaque index) and plaque samples from 68 CP, 12 AgP, and 30 periodontally healthy subjects were analyzed. Subgingival samples were processed using culture, biochemical tests, and polymerase chain reaction for the detection of periodontal and superinfecting pathogens. The analysis of variance, chi(2), and Kruskal-Wallis tests were used to evaluate differences between groups for clinical parameters and microbiologic composition (P <or=0.05).

RESULTS

Clinical parameters were significantly increased in CP and AgP patients compared to healthy subjects (P <0.001), but no differences were found between periodontitis groups. Porphyromonas gingivalis, Tannerella forsythensis, and Eikenella corrodens showed higher frequencies in AgP compared to CP and healthy subjects (P <0.05). Extension (localized and generalized) of the periodontal destruction had no effect on the composition of the subgingival microbiota. Gram-negative enteric rods were more frequent in AgP patients (P <0.01).

CONCLUSIONS

This study demonstrated a high prevalence of P. gingivalis, T. forsythensis, and E. corrodens in AgP patients. Gram-negative enteric rods were frequent in AgP and CP patients. Differences in the composition of subgingival microbiota in periodontitis patients need to be taken into account when considering the best therapeutic approach for each individual, including the use of antibiotics.

In vitro minocycline activity on superinfecting microorganisms isolated from chronic periodontitis patients

Chronic periodontitis is the most common type of periodontitis and it is associated with various species of microorganisms. Enteric rods, Pseudomonas, Staphyloccocus and Candida have been retrieved from periodontal pockets of patients with chronic periodontitis and correlated to cases of superinfection. Local or systemic antibiotic therapy is indicated to reinforce the effects of the conventional mechanical therapy. Minocycline has been suggested as one of the most effective drugs against periodontal pathogens. The aim of this work was to evaluate the minimal inhibitory concentration (MIC) of minocycline on superinfecting microorganisms isolated from the periodontal pocket and the oral cavity of individuals with chronic periodontitis. Isolates of Enterobacteriaceae (n = 25), Staphylococcus spp. (n = 25), Pseudomonas aeruginosa (n = 9) and Candida spp. (n = 25) were included in the study. Minimal inhibitory concentrations (MIC) of minocycline were determined using the Müeller-Hinton agar dilution method. Staphylococcus spp. isolates were the most sensitive to minocycline with a MIC of 8 µg/mL, followed by Enterobacteriaceae with a MIC of 16 µg/mL. The concentration of 16 µg/mL inhibited 96% of Candida spp. isolates. The MIC for 88.8% of the isolates of Pseudomonas aeruginosa was 128 µg/mL. A concentration of 1,000 µg/mL was not enough to inhibit 100% of the tested isolates.

Characterization of Serratia marcescens isolates from subgingival biofilm, extraoral infections and environment by prodigiosin production, serotyping, and genotyping

INTRODUCTION

Serratia marcescens is widely distributed in nature, and has emerged in the last years as an important nosocomial pathogen. The organism may also be found in subgingival biofilm in periodontitis patients. This study aimed to verify the subgingival prevalence of S. marcescens in different periodontal conditions and to evaluate whether the oral cavity would harbor strains similar to those causing infectious diseases.

METHODS

The subgingival occurrence of S. marcescens was determined in 334 subjects. The phenotypic and genotypic diversity of 23 isolates from subgingival biofilm, 22 from extra-oral infections and 10 environmental strains, was compared by prodigiosin production, O and H serotyping and genotyping using polymorphic GC-rich repetitive sequences-polymerase chain reaction.

RESULTS

S. marcescens was found more frequently in severe periodontitis patients (4.1%) than in gingivitis (3.2%) and healthy subjects (2.5%), but these differences were not statistically significant. Analysis of serotype distribution, prodigiosin production, and genotyping revealed that environmental strains were markedly different from most human isolates, either oral or extraoral.

CONCLUSION

These data suggest that S. marcescens isolates from subgingival biofilm are not just contaminants from the environment, but that the oral cavity may act as a reservoir of strains able to promote human infections. However, further studies are needed to elucidate the role of this bacterium in the pathogenesis of periodontal diseases.

Clinical and microbiological characterization of periodontal abscesses

BACKGROUND/AIM

The knowledge of clinical features, microbial composition and susceptibility to antimicrobials of periodontal abscesses has recently improved. This descriptive clinical and microbiological study provides more information on the characteristics of periodontal abscesses.

MATERIALS AND METHODS

Clinical parameters and subgingival samples were examined from 54 subjects presenting 60 periodontal abscesses. Samples were cultured for anaerobic and facultative bacteria, and data were expressed as frequency detection and mean proportion of isolation for microorganisms. Selected isolates of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia/nigrescens were used to test susceptibility to amoxicillin, azithromycin, tetracycline and metronidazole. Statistical descriptive analysis was conducted.

RESULTS

Most periodontal abscesses were present in patients with ongoing Chronic Periodontitis. Bleeding on probing, tumefaction and suppuration were present in almost all abscesses. Affected teeth were lower anterior teeth, upper anterior teeth and lower molars. The subgingival microbiota was composed of periodontal pathogens such as Fusobacterium spp. (75%), P. intermedia/nigrescens (60%), P. gingivalis (51%) and A. actinomycetemcomitans (30%). Some periodontopathogens showed antimicrobial resistance to tetracycline, metronidazole and amoxicillin, but not to azithromycin.

CONCLUSIONS

Periodontal abscesses showed typical clinical features associated with untreated periodontitis, and the organisms identified were important periodontopathic bacteria. Rationale use of antibiotic adjunctive therapy in abscess treatment should be taken into account.

Relationship of Subgingival and Salivary Microbiota to Gingival Overgrowth in Heart Transplant Patients Following Cyclosporin A Therapy

BACKGROUND

Severe gingival overgrowth (GO) is induced in patients taking cyclosporin A (CsA) following organ transplantation. Determining which patient will develop GO is still not possible. The purpose of this study was to establish an association between CsA and gingival overgrowth in heart transplant patients taking into account periodontal and microbiological conditions.

METHODS

Thirty patients (10 female, 20 male; range: 13 to 67 years; mean age: 44.89) undergoing CsA treatment were evaluated using the gingival index (GI), plaque index (PI), probing depth (PD), and clinical attachment level (CAL). Subgingival samples collected from the deepest site of each quadrant and saliva samples were submitted to microbial analysis. All patients had at least 12 teeth. Exclusion criteria were the use of antibiotics and/or having undergone periodontal treatment 6 months prior to the study. Patients were divided in two groups: with gingival (GO+) and without gingival overgrowth (GO-).

RESULTS

There were no statistically significant differences between the GO+ and GO- groups when CsA dosage, time since transplant, GI, PI, PD, and CAL were compared. Microbiological examination of the subgingival samples detected the following microorganisms: Actinobacillus actinomycetemcomitans (23%), Porphyromonas gingivalis (36%), Prevotella intermedia (93%), Fusobacterium sp. (66%), Campylobacter rectus (30%), Micromonas micros (66%), enteric rods (0%), and yeasts (30%). A positive association between M. micros and the GO+ group was found (P < 0.001). Yeasts were detected in 30% of the subgingival and saliva samples.

CONCLUSIONS

Clinical parameters were not sufficient to determine which patients would develop GO. However, colonization by M. micros might play a role in the etiology of GO.

Isolation and characterization of subgingival staphylococci from periodontitis patients and controls

OBJECTIVES

To isolate and characterize subgingival staphylococci from patients with periodontal disease and from periodontally healthy controls, to evaluate the periodontal environment as a potential source for systemic staphylococcal infections.

METHODS

Periopaper strips were used to isolate subgingival staphylococci from 28 patients with chronic periodontitis and 28 periodontally healthy age and sex-matched controls. Staphylococci were identified by microbiological methods and antibiotic resistance profiles determined.

RESULTS

Staphylococci were isolated from 54% diseased subgingival and 43% healthy subgingival sites in over 50% periodontitis patients and from 29% healthy subgingival sites in 54% controls. No significant differences in the frequency of isolation or numbers of staphylococci isolated from diseased and healthy sites were noted. Staphylococcus epidermidis was the predominant oral species. Seventy per cent (115 of 165) of all isolates were penicillin-resistant.

CONCLUSIONS

Subgingival staphylococci are present in both periodontitis patients and controls. In periodontitis there is an increased risk of bacteraemia because of the increased dentogingival surface area. The dental and periodontal health of patients at risk from haematogenous infections should therefore be maintained at a high level. Antibiotic resistance profiles of the oral staphylococcal isolates suggest that amoxicillin may no longer be a suitable antibiotic for prophylaxis against systemic infections such as prosthetic valve endocarditis.

In vitro antifungal susceptibility of Candida spp. isolates from patients with chronic periodontitis and from control patients

Superinfection by Candida can be refractory to conventional periodontal treatments in specific situations, such as in immunocompromised patients. In these cases, the systemic therapy with antifungal drugs could be indicated. The aim of this study was to analyse antifungal susceptibility of Candida spp. strains isolated from chronic periodontitis patients and from control individuals. A total of 39 C. albicans isolates, 9 C. tropicalis, 2 C. glabrata and 5 Candida spp. from control individuals and 30 C. albicans, 3 C. tropicalis and 2 C. glabrata from periodontitis patients were tested. In the control group, 1 isolate of C. glabrata was resistant to ketoconazole and 1 Candida spp. was resistant to amphotericin B, ketoconazole and miconazole. Among the isolates of periodontitis group, 1 (3.33%) C. albicans isolate was resistant to flucytosine and ketoconazole. According to the obtained results, it could be concluded that fluconazole was the most effective drug against the several Candida species studied. There were not expressive differences in the susceptibility of isolates from periodontitis patients or from control individuals.

Superinfecting microorganisms in patients under treatment with cyclosporin-A and its correlation to gingival overgrowth

The aim of this study was to identify the presence of superinfecting microorganisms (Gram-negative enteric rods and Candida sp.) in heart transplant patients and correlate this with gingival overgrowth. Thirty patients (10 females, 20 males--mean age 45 years) were examined. All were under cyclosporin-A (CsA) therapy. Patients who had taken any antibiotics 3 months prior the study or had been submitted to periodontal therapy were not enrolled. Patients were required to have at least 6 teeth. The plaque index (PI), gingival index (GI), pocket depth (PD) and clinical attachment level (CAL) were recorded. Microbiological samples were taken from sulcus/pocket (s/p) and from stimulated saliva (ss) and submitted to analysis. Patients were divided into two groups: the ones with gingival overgrowth (GO) and those without gingival overgrowth (WGO). After statistical analysis (chi-square test, Student's t-test, Fisher test, p < or = 0.05), we concluded that there was no statistical difference between groups in the parameters of gender, CsA dosage, time since transplantation, PI, GI, PD and CAL. Gram-negative rods from either the sulcus/pocket or saliva samples were not found. Candida sp. was detected (s/p-30% and ss-30%). Stimulated saliva samples analysis determined that the presence of Candida sp. was associated with patients without gingival overgrowth.

Genotyping and antifungal susceptibility of human subgingival Candida albicans isolates

Subgingival colonization by Candida albicans has been described in human immunodeficiency virus (HIV)-infected individuals, but subgingival isolates have scarcely been characterized, particularly with respect to genotype and antifungal susceptibility. A series of 29 subgingival strains of C. albicans isolated from nine HIV-infected individuals was typed by electrophoretic karyotyping and tested for susceptibility to fluconazole, itraconazole, the new investigational triazole posaconazole and amphotericin B. DNA typing showed genetic heterogeneity within subgingival isolates, as almost every individual harbored his/her own specific isolate. Genetic identity was usually demonstrated within oral and subgingival isolates simultaneously collected from the same individual, but a number of DNA types were found to be unique to subgingival strains. These findings suggest that colonization is not just the result of Candida spreading from oral surfaces, and that subgingivally adapted strains could be involved. All isolates were susceptible to all the triazole drugs tested and amphotericin B. Additional studies on subgingival Candida colonization and further characterization of subgingival isolates are now required to clarify the role of Candida as opportunistic periodontal pathogen.

Subgingival occurrence and antimicrobial susceptibility of enteric rods and pseudomonads from Brazilian periodontitis patients

The occurrence and in vitro antimicrobial sensitivity of isolates of enteric rods and pseudomonads were examined in 80 periodontitis patients, 17 to 58 years of age, in São Paulo, Brazil. Speciation and in vitro antimicrobial susceptibility testing were performed using the BBL Crystal enteric/nonfermenter system and the Etest for amoxicillin/clavulanic acid, ciprofloxacin and doxycycline. A total of 30 strains were isolated from 25 (31.2%) of the study subjects. Pseudomonas aeruginosa occurred in nine patients, Serratia marcescens in seven, and five other species were recovered in lower prevalence. All study organisms demonstrated high susceptibility to ciprofloxacin but exhibited variable susceptibility patterns to the other antimicrobial agents tested. In conclusion, the high occurrence of enteric rods and pseudomonads in these subjects may be important in the pathogenesis of periodontitis, and ciprofloxacin might be the antibiotic of choice to eradicate these pathogens from periodontal pockets.

Yeasts in periodontal pockets

OBJECTIVES

The presence of yeasts in periodontal pockets has been described in a few studies. The association between yeasts and putative periodontal pathogens is not well described. This study aims at assessing the prevalence of yeasts in periodontal pockets and possible associations with the clinical conditions of the sampled sites and other micro-organisms present.

MATERIAL AND METHODS

2 subject groups form the basis for this study. The 1st comprises results from microbiological samples from periodontal pockets of 128 subjects. The 2nd originates from 126 periodontal patients with untreated pockets. Microbiological identification was performed after cultivation on blood and Sabouraud agar plates, and "checkerboard" DNA-DNA hybridisation.

RESULTS

The prevalence of subjects with yeasts in the pockets was 15.6% and 17.5% in the 2 groups respectively and was inconsistent according to gender. No correlation was found between age and the presence of yeasts. Eubacterium saburreum was weakly correlated with presence of yeasts (r=0.194 p=0.03). Yeasts were rarely found in both samples from the same individual.

CONCLUSIONS

Our results indicate that yeasts can be expected to be present in periodontal pockets in one out of 6 periodontal patients independent of gender and age. Eubacterium saburreum seems to occur frequently together with yeasts.

Untreated periodontal disease in Indonesian adolescents. Subgingival microbiota in relation to experienced progression of periodontitis

BACKGROUND/AIMS

In an Indonesian population deprived of regular dental care, the experienced progression of disease between baseline (1987) and follow-up (1994) was investigated in relation to the composition of the subgingival microbiota at follow-up. At baseline the age ranged from 15 to 25 years. Clinical and microbiological evaluation was completed in 158 of the 167 subjects available at follow-up.

METHODS

Plaque index (PI), pocket depth (PD), bleeding on probing (BOP), and attachment loss (AL) were scored at the approximal surfaces of all teeth and subgingival calculus on the approximal surfaces of the Ramfjord teeth only (number of sites with subgingival calculus: NSC). A pooled sample of the deepest pocket in each quadrant was evaluated using microbiological culture techniques.

RESULTS

At baseline the mean values of the clinical parameters were AL=0.35 mm, PI=1.01, BOP=0.80 PD=3.25 mm and NSC=6.04 and at follow-up AL=0.75 mm, PI=1.16, BOP=1.19, PD=3.34 mm and NSC=5.85. All parameters except PD and NSC showed a statistically significant increase. At follow-up the prevalence of Actinobacillus actinomycetemcomitans was 40%, of Porphyromonas gingivalis 67%, of Prevotella intermedia 66%, of Fusobacterium nucleatum 79%, of Bacteroides forsythus 16%, of Campylobacter rectus 4%, and of P. micros 6%. No differences in clinical parameters were found between groups with or without these micro-organisms. In 129 subjects AL of > or =2 mm at > or =1 site was found. Logistic regression showed three significant odds-ratio's for experienced progressive periodontitis: Plaque index (12.2), gender (3.4) and Actinobacillus actinomycetemcomitans (2.9).

CONCLUSIONS

The results of this retrospective study suggest that plaque is the most important parameter related to experienced disease progression, and that the presence of A. actinomycetemcomitans may be associated with increased chance of disease progression.

Subgingival strains of Candida albicans in relation to geographical origin and occurrence of periodontal pathogenic bacteria

Clonal diversity of subgingival yeast strains was determined in relation to geographical location and coexistence of selected periodontal pathogenic bacteria. A total of 60 dental patients from Finland, the United States and Turkey each contributed five Candida albicans isolates. C. albicans isolates were serotyped using slide agglutination and genotyped using polymerase chain reaction (PCR) amplification and a random sequence primer. In general, each study subject yielded C. albicans isolates belonging to the same serotype and genotype. C. albicans serotype A occurred more frequently in subjects from Finland and Turkey than in subjects from the United States. A total of 27 PCR-based C. albicans genotypes were identified. One C. albicans genotype occurred with particularly high frequency in subjects from Turkey and another genotype in subjects from the United States. Relationships were identified between C. albicans serotypes and genotypes. Further studies are needed to determine environmental factors of importance for subgingival colonization and persistence of C. albicans.

Oral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci in irradiated, dentate, xerostomic individuals

This study aimed at investigating the oral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci in head- and neck-irradiated, dentate, xerostomic individuals. Subjects were recruited from a nasopharyngeal carcinoma clinic and were segregated into group A: <60 years (n=25, 48+/-6 years, 5+/-5 years post-irradiation) and group B: >or=60 years (n=8, 67+/-4 years, 2+/-2 years post-irradiation) and were compared with age- and sex-matched normal individuals, group C: <60 years (n=20, 44+/-12 years) and group D: >or=60 years (n=10, 70+/-3 years). Selective culture of the oral rinse samples was carried out to isolate, quantify and speciate (using API 20E kit) aerobic and facultatively anaerobic gram-negative rods and cocci recovery. All test subjects were put under comprehensive oral and preventive care for 3 months, and 12 group A and 5 group B subjects were recalled for reassessment of aerobic and facultatively anaerobic gram-negative rods and cocci colonization. All identical isolates, pre- and post-hygienic care, were phenotypically (Vitek, Hazelwood, MA and antibiogram profile) and genotypically (pulsed-field gel electrophoresis) evaluated. The aerobic and facultatively anaerobic gram-negative rods and cocci isolated from the first round oral rinse samples included: Acinetobacter, Neisseria, Chryseomonas, Flavimonas, Pseudomonas, Citrobacter, Enterobacter, Escherichia, Klebsiella, Flavobacterium and Weeksella species. The aerobic and facultatively anaerobic gram-negative rods and cocci isolation rate was high for irradiated individuals, and they were 64/25% and 100/80% for groups A/C and B/D, respectively. Recovery of aerobic and facultatively anaerobic gram-negative rods and cocci and Klebsiella pneumoniae subsp. pneumoniae in oral rinse samples were found to be significantly more prevalent in the irradiated subjects (groups A and B). Enterobacteriaceae were more frequently isolated from oral rinse samples of aged irradiated subjects (group B vs D, P<0.05), where the quantity of Citrobacter freundii (colony-forming units/ml oral rinse) was also significantly elevated. The isolation rate of aerobic and facultatively anaerobic gram-negative rods and cocci after hygienic care remained unchanged; 3 of 12 and 3 of 5 of the recalled subjects from groups A and B, respectively, harbored same aerobic and facultatively anaerobic gram-negative rods and cocci species. However, only two pairs of K. pneumoniae subsp. pneumoniae, sequentially isolated from same patients in group B, were found to be identical by pulsed-field gel electrophoresis. This may be due to reinfection of the microbes from the same source or permanent colonization. In conclusion, irradiation-induced xerostomia seems to favor frequent, repeated, transient intraoral colonization of aerobic and facultatively anaerobic gram-negative rods and cocci.

Early-onset periodontitis

In 1993, the 1st European Workshop on Periodontology explicitly recognized that there was insufficient knowledge to differentiate truly different forms of periodontal disease from differences in the presentation/severity of the same disease. In spite of recent progress in our understanding of periodontal diseases, the issue is far from having been resolved. Classification of periodontal diseases, therefore, remains based upon the definition of specific clinical syndromes. Early-onset periodontitis (EOP) is one such syndrome and comprises a group of pathological conditions leading to loss of periodontal tissues early in life. The notion that classifies periodontitis syndromes as "early-onset" or "adult" is primarily epidemiological in nature and is based on the observation that periodontitis is rather infrequent in children and young adults. Nevertheless, considerable epidemiological evidence indicates that periodontitis does affect children and young adults to a level of severity that may lead to premature exfoliation of primary and/or permanent teeth. Clinical presentation of periodontitis early in the life of an individual is thought to indicate that the etiologic agents have been able to cause considerable tissue damage over a relatively short period of time. It also implies either infection with highly virulent bacteria and/or a highly susceptible subject. The purpose of this review is to discuss the criteria generally utilized to classify EOP, provide the rationale to designate EOP as a distinct disease entity, and to review the evidence justifying a subclassification into particular subgroups of EOP.

In vitro antifungal properties of mouthrinses containing antimicrobial agents

The purpose of this study was to investigate the in vitro antifungal properties of seven commercial mouthrinses containing antimicrobial agents. These included cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), hexetidine (HEX), sanguinarine (SNG), and triclosan (TRN). The minimum fungicidal concentration (MFC) against six species of yeasts was determined by a broth macrodilution method. The kill-time of mouthrinses at half the concentration of the commercial formulations was also determined. MFCs were achieved with each mouthrinse, except the SNG-containing mouthrinse, against all the organisms being tested. However, the CPC-containing mouthrinse appeared more active than the other products (P < 0.001). There were no significant differences in MFC values among CHX mouthrinse products, once adjusted for initial concentration differences (P = 0.1). Kill-times of mouthrinses containing either CHX or CPC were less than or equal to 180 seconds with all the species of yeasts, and no significant differences were found among these products (P = 0.18). On the other hand, mouthrinses containing either TRN or HEX did not show a lethal effect on Candida albicans, Candida parapsilosis, or Candida guilliermondii. No kill-times were achieved with the SNG-containing mouthrinse. These results suggest that mouthrinses containing antimicrobial agents might represent an appropriate alternative to conventional antifungal drugs in the management of oral candidiasis. However, the effectiveness of antimicrobial mouthrinses as antifungal agents needs to be evaluated in further clinical trials.

Utility of 5 major putative periodontal pathogens and selected clinical parameters to predict periodontal breakdown in patients on maintenance care

The predictive utility of 5 major putative periodontopathic microbial species, "superinfecting" organisms, and several clinical periodontal parameters were assessed relative to periodontitis recurrence over a 12-month period in 78 treated adult patients participating in a 3-month maintenance care program. At baseline, pooled subgingival microbial samples were collected from each patient, and whole-mouth evaluations of probing depth, relative periodontal attachment level, furcation involvement, and indices of plaque and gingival inflammation were carried out. 67 (85.9%) subjects were culture-positive at baseline for presence of either Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Campylobacter rectus or Peptostreptococcus micros, with 48 (61.5%) subjects yielding one or more of these species at or above designated threshold proportions of > or = 0.01% for A. actinomycetemcomitans, > or = 0.1% for P. gingivalis, > or = 2.5% for P. intermedia, > or = 2.0% for C. rectus, and > or = 3.0% for P. micros. Subgingival yeasts were recovered from 12 subjects, staphylococci from 7, and enteric rods/pseudomonads from 6; however, no subjects revealed > or = 1.0% baseline proportions of these "superinfecting" organisms in subgingival specimens. Periodontitis recurrence in subjects was defined as any periodontal site exhibiting either a probing depth increase of > or = 3 mm from baseline, or a probing depth increase of > or = 2 mm from baseline together with a loss in relative periodontal attachment of > or = 2 mm from baseline. 15 (19.2%) study subjects showed periodontitis recurrence within 6 months of baseline, and 25 (32.1%) within 12 months. The mere baseline presence of the 5 major test species and "superinfecting" organisms were not significant predictors of periodontitis recurrence over 12 months. However, a 2.5 relative risk for periodontitis recurrence over 12 months was found for subjects yielding one or more of the 5 major test species at or above the designated baseline threshold proportions (p = 0.022, Mantel-Haenszel chi 2 test). The positive predictive value for periodontitis recurrence of a microbiologic analysis encompassing the 5 major test species at or above the designated threshold proportions improved with increasing time from baseline, up to approximately 42% at 12 months. Baseline variables jointly providing in multiple regression analysis the best predictive capability for periodontitis recurrence in subjects over a 12-month period were recovery of one or more of the 5 major test species at or above designated threshold proportions, the proportion of sites per subject with > or = 5 mm probing depth, and the mean whole-mouth probing depth. These findings indicate that one or more of 5 major putative periodontal pathogens in elevated subgingival proportions together with increased probing depth predispose adults on maintenance care to recurrent periodontitis.

Occurrence of certain bacterial species and morphotypes in juvenile periodontitis in Chile

The occurrence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Eikenella corrodens, Fusobacterium nucleatum, Campylobacter rectus, Capnocytophaga species, and certain bacterial morphotypes was determined in 18 affected and 18 unaffected sites in 10 localized juvenile periodontitis (LJP) patients, and in 10 affected and 10 unaffected sites in 5 generalized juvenile periodontitis (GJP) patients. The subgingival proportion of the 7 bacterial species was determined by selective and nonselective culturing. The results showed that when considering the pure prevalence of bacteria ( > 0%) there were significant differences (P < 0.05) in the subgingival plaque microflora of the affected sites versus those of the unaffected sites for P. gingivalis, A. actinomycetemcomitans, P. intermedia, E. corrodens, C. rectus, and F. nucleatum in LJP, and for P. gingivalis, P. intermedia, and F. nucleatum in GJP. The mean proportions of cocci, motile rods and spirochetes were also significantly different (P < 0.05) in affected sites compared to unaffected sites. Capnocytophaga sp, F. nucleatum, P. intermedia, and E. corrodens were found in more than 75% of affected sites in LJP. When taking the approach that an organism, to be associated with periodontal disease, has to be detected above a certain minimum threshold, the results indicated that bacteria most frequently associated with LJP and GJP in Chile are P. gingivalis (66% of LJP and 80% of GJP affected sites), and A. actinomycetemcomitans (44% of LJP and 50% in GJP affected sites). Different bacterial species may be judged to be important in the disease process depending upon whether a pure bacterial prevalence, or a prevalence above a certain detection level, is considered.

Occurrence of enteric rods, staphylococci and Candida in subgingival samples

The frequency and percentage of enteric rods, staphylococci and Candida were determined in 973 subgingival samples collected from 535 patients subjected to different periodontal treatment procedures. The analysis was performed with culture technique using selective and nonselective media. One or more organisms were detected in 65.5% of the samples and in 76.7% of the patients. In most samples enteric rods, staphylococci and/or Candida constituted a small amount of the total microbial viable count. Enteric rods exceeded 10% of the total viable count in 30 samples. Staphylococci occurred in more than 10% in only 3 samples. In these 3 samples, enterics constituted more than 10% of the total viable count. Candida was not found to exceed 10% of the total viable count in any of the samples. No statistically significant correlation was found between the presence of any of the target microorganisms and kind of periodontal treatment procedure received, antibiotic administration or sample transport time.