Yeasts in juvenile periodontitis. Preliminary observations by scanning electron microscopy

Occurrence of Candida albicans in Periodontitis

Background

Periodontal diseases are the result of an imbalance between the microbiota and immune defense. The role of yeast in the pathogenesis of these diseases has been studied. This study aims to assess the occurrence of Candida albicans in periodontitis.

Materials and Methods

Fifty subjects were recruited for the study (15 healthy individuals and 35 periodontitis subjects). The periodontal examination and plaque sampling were carried out for all patients. Candida albicans identification was based on culture, direct examination, and polymerase chain reaction. The statistical analysis was performed by SPSS 20 (SPSS Inc., Chicago, IL, USA).

Results

Twenty percent of the diseased group harbored Candida albicans which was slightly higher than in the healthy group (7%), suggesting that, under normal conditions, yeast does not grow easily in subgingival sites. However, no significant difference between the healthy and periodontitis groups (p=0.23) was found. Our results also indicated that the presence of Candida albicans was neither gender nor age related in the studied groups.

Conclusion

The results of this study suggest that Candida albicans occurs in periodontitis. More studies are needed to clarify the potential role of this yeast in different stages and forms of the disease.

In vitro adherence of Candida albicans isolated from patients with chronic periodontitis

Adherence is considered an extremely important virulence factor in yeast.

OBJECTIVE

The aim of this study was to analyze the adherence to epithelial cells of C. albicans isolated from patients with chronic periodontitis in comparison to healthy patients.

MATERIAL AND METHODS

Candida albicans cells isolated from individuals with chronic periodontitis (n=25) and healthy controls (n=25) were included in this study. Suspensions of C. albicans (10(6) cells/mL) and epithelial cells (10(5) cells/mL) were mixed and incubated at 37ºC for 1 h. The number of yeasts adhered to 25 epithelial cells was counted.

RESULTS

The number of C. albicans cells adhered to epithelial cells was statistically higher in the chronic periodontitis group than in the control group (Student's t-test, p=0.000).

CONCLUSION

The results of the present study suggest a higher Candida adherence of samples isolated from patients with chronic periodontitis.

Periodontal conditions and prevalence of putative periodontopathogens and Candida spp. in insulin-dependent type 2 diabetic and non-diabetic patients with chronic periodontitis--a pilot study

OBJECTIVES

The aims of this study were to evaluate periodontal conditions and identify the presence of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia, and four different species of Candida (C. albicans, C. dubliniensis, C. glabrata and C. tropicalis) in periodontal pockets and furcation sites of insulin-dependent type 2 diabetic and non-diabetic patients with generalised chronic periodontitis.

DESIGN

Clinical parameters, including oral status assessed using plaque index, gingival index, probing depth, gingival recession and clinical attachment level and systemic conditions with fasting glucose level or glycosylated haemoglobin were measured in diabetic and non-diabetic patients with chronic periodontitis. Samples of subgingival biofilm were obtained from the periodontal pockets and furcation sites and submitted to phenol-chloroform DNA extraction and PCR analysis using specific primers.

RESULTS

Clinical conditions of diabetic and non-diabetic patients were similar, without statistical differences in both periodontal indexes and glucose levels (p>0.05). Diabetics had a higher prevalence of Candida spp., mainly C. albicans and C. dubliniensis, and a lower frequency of T. forsythia, when compared to non-diabetic patients, for both periodontal sites. C. glabrata and C. tropicalis were not found in periodontal pockets and furcation sites of non-diabetic patients.

CONCLUSION

The results demonstrated a strong colonisation of Candida spp. in the periodontal sites of diabetic patients that have generalised chronic periodontitis with a higher prevalence of C. dubliniensis followed by C. albicans.

Candida spp. in periodontal disease: a brief review

Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. Such interactions are associated with the capacity of Candida spp. to invade gingival conjunctive tissue, and may be important in the microbial colonization that contributes to progression of oral alterations caused by diabetes mellitus, some medications, and immunosuppressive diseases such as AIDS. In addition, immune deficiency can result in proliferation of Candida spp. and germination of forms that are more virulent and have a higher capacity to adhere to and penetrate cells in host tissues. The virulence factors of Candida spp. increase host susceptibility to proliferation of these microorganisms and are likely to be important in the study of periodontal disease. Herein, we briefly review the literature pertaining to the role of Candida spp. in periodontal disease, and consider the main virulence factors, the host immune response to these microorganisms, and the effect of concomitant immunosuppressive conditions.

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.

Genetic diversity and exoenzyme activities of Candida albicans and Candida dubliniensis isolated from the oral cavity of Brazilian periodontal patients

OBJECTIVE

Mucosal surfaces are the primary oral reservoirs of Candida species, but these species can also be found in subgingival biofilm. The present study investigated the genetic diversity and production of exoenzymes of C. albicans and C. dubliniensis isolated from the oral cavity of systemically healthy patients with periodontitis.

DESIGN

Fifty-three patients were analysed. Samples were collected from three oral cavity sites (periodontal pocket, gingival sulci and oral mucosa), plated and, after isolation, suspect strains of C. albicans and C. dubliniensis were identified by PCR. The genetic diversity of the isolates was evaluated by RAPD and the activities of the secreted aspartyl proteinases and phospholipases were evaluated by the agar plate method.

RESULTS

Twenty-one patients showed positive results for Candida spp. There were no statistically significant differences between genders, or between sites. C. albicans was the most frequently found specie, while C. dubliniensis was isolated from the periodontal pocket of only one patient. Sixteen genotypes were detected among the C. albicans isolates, and one among the C. dubliniensis isolates. The similarity coefficient (S(SM)) values among the C. albicans genotypes ranged from 0.684 to 1.0 with an average of 0.905+/-0.074. All isolates produced high levels of Saps and most of them produced high levels of phospholipases. No relationship was found between the genotypes and the pattern of enzymatic production. There was no association between specific genotypes and their site of isolation.

CONCLUSIONS

The results of the present study suggest that genetically homogeneous strains of C. albicans are present in the oral cavity of patients with periodontitis and that these strains are capable of producing high levels of exoenzyme.

Candida yeasts in chronic periodontitis tissues and subgingival microbial biofilms in vivo

The frequency of Candida infection in periodontal tissues of chronic periodontitis (CP) patients and the extent of candidal penetration into gingival tissues was studied. Tissue specimens collected from 25 CP patients during periodontal flap operations of initial periodontal therapy were examined by immunohistochemistry using Candida albicans-specific antibodies. Sections were also stained with periodic acid-Schiff (PAS) and subgingival plaque samples from 17 patients were cultured. Immunoreactivity for Candida was present in four of the 25 CP specimens (16%). Only one yeast-positive specimen was found when PAS-staining was used (4%) and two yeast-positive specimens were found with plaque culture (8%). Hyphal formation seemed essential and candidal hyphae were found to extend into the periodontal connective tissue. The degree and type of inflammation adjacent to the hyphae varied from a site and a patient to another. The sensitivity of specific antibodies was superior to PAS-stain or plaque culture in detection of Candida in tissues.

A systematic review on the effect of systemic antimicrobials as an adjunct to scaling and root planing in periodontitis patients

BACKGROUND

Scaling and root planing (SRP) are the bases of non-surgical therapy in the treatment of periodontitis. However, results from this therapy are often unpredictable and dependable from many different factors.

OBJECTIVES

The aim of this systematic review was to evaluate the effectiveness of the adjunctive use of systemic antimicrobials with scaling and root planing (SRP) vs. SRP alone in the treatment of chronic (CP) or aggressive periodontitis (AgP).

SEARCH STRATEGY

Use of computerized databases, namely MEDLINE, the Cochrane Oral Health Group Specialty Trials Register and EMBASE; reference lists from relevant articles were hand-searched; and a hand-search of selected journals until April 2001.

SELECTION CRITERIA

Studies were selected if they were designed as controlled clinical trials in which systemically healthy patients with either AgP or CP were treated with SRP plus systemic antimicrobials in comparison with SRP alone or with placebo, for a minimum of 6 months. Main outcome measures were clinical attachment level (CAL) change and probing pocket depth (PPD) change.

DATA COLLECTION AND ANALYSIS

Two reviewers extracted independently information regarding quality and study characteristics, in duplicate. Kappa scores determined their agreement. Main results were collected and grouped by drug, disease and PPD category. For the quantitative data synthesis, the data was pooled (when mean differences and standard errors were available), and either a Fixed Effects or Random Effects meta-analysis was used for the analysis.

RESULTS

After an initial selection, 158 papers were identified by the manual and electronic searches; 25 papers were eligible for inclusion. Their quality assessment showed that randomization and allocation concealment methods were seldom reported and blindness was usually not defined clearly. In general, selected studies showed high variability and lack of relevant information for an adequate assessment. Overall, SRP plus systemic antimicrobial groups demonstrated better results in CAL and PPD change than SRP alone or with placebo groups. Only limited meta-analyses could be performed, due to the difficulties in pooling the studies and the lack of appropriate data. This analysis showed a statistically significant additional benefit for spiramycin (PPD change) and amoxicillin/metronidazole (CAL change) in deep pockets.

CONCLUSION

Systemic antimicrobials in conjunction with SRP, can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of CAL and PPD change, and reduced risk of additional CAL loss. However, differences in study methodology and lack of data precluded an adequate and complete pooling of data for a more comprehensive analyses. It was difficult to establish definitive conclusions, although patients with deep pockets, progressive or 'active' disease, or specific microbiological profile, can benefit more from this adjunctive therapy.

Salivary IgA subclasses and bacteria-reactive IgA in patients with aggressive periodontitis

The local salivary immunoglobulin A (IgA) response in patients with aggressive periodontitis to oral microorganisms and its role for the pathogenesis has not been determined. This study investigated the hypothesis that aggressive periodontitis patients have impaired oral secretory immunity. Our test group was made-up of 19 aggressive periodontitis patients and 19 age- and gender-matched periodontally healthy controls. Total IgA, IgA subclass 1, IgA subclass 2 and IgA reactive to Actinobacillus actinomycetemcomitans Y4, Treponema denticola ATCC 35404 and Candida albicans DSM 3454 were determined by enzyme-linked immunosorbent assay in whole unstimulated and stimulated saliva. A statistically significantly lower concentration and secretion rate of total salivary IgA (P < 0.01) and IgA1 (P < 0.001) was found in the aggressive periodontitis group in resting and stimulated saliva. A decrease of IgA2 (P < 0.05) was seen in resting saliva. Although only minor differences were detected in the concentration and secretion of bacteria-reactive IgA in both groups, the proportion of bacteria-reactive IgA from the total IgA was significantly higher (P < 0.01) in the aggressive periodontitis group in all three microorganisms tested. Our results indicate an inhibition of total secretory IgA. In particular an IgA subclass 1-specific decrease in aggressive periodontitis was noted, while the bacteria-reactive humoral immune system in saliva was activated. The role of the decrease of IgA1 immunoglobulins in aggressive periodontitis with respect to susceptibility for periodontal diseases has to be elucidated.

PRESENÇA DE LEVEDURAS DO GÊNERO CANDIDA NA SALIVA DE PACIENTES COM DIFERENTES FATORES PREDISPONENTES E DE INDIVÍDUOS CONTROLE

Os microrganismos do gênero Candida são, em geral, comensais da cavidade bucal, mas, em determinados indivíduos e em situações específicas, podem transformar-se na forma parasitária, produzindo candidoses bucais. O objetivo deste trabalho foi analisar a presença das espécies do gênero Candida na saliva de indivíduos controle, comparando com pacientes que apresentavam diferentes fatores predisponentes. Foram avaliados 493 pacientes, divididos em 7 grupos: prótese total, prótese parcial removível, periodontite crônica de adulto, respiração bucal, aparelho ortodôntico fixo, aparelho ortodôntico removível e aparelho extrabucal. O grupo controle consistiu de 570 indivíduos que não apresentavam nenhum desses fatores, divididos em 2 grupos: infantil e adulto. Foram realizados o isolamento e a identificação das espécies do gênero Candida. Os resultados mostraram maior porcentagem de pacientes positivos para Candida nos grupos com fatores predisponentes em relação aos controles. Houve predominância de isolamento de C. albicans em todos os grupos, porém, os pacientes com fatores predisponentes apresentaram diversidade maior de espécies

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.

Growth patterns of Candida albicans in relation to radicular dentin

Candida albicans is the most common fungal pathogen isolated from the oral cavity. The role of this organism as an endodontic pathogen is poorly understood.

OBJECTIVES

The aim of this study was to observe the interaction of C. albicans with root canal walls and the growth patterns of this microorganism in relation to radicular dentin.

STUDY DESIGN

Fifteen root sections were infected with C. albicans grown in calf serum and incubated for various periods. The sections were fixed in glutaraldehyde, split into two halves, and evaluated by scanning electron microscopy.

RESULTS

Blastospores and hyphal structures were observed on the root canal walls of all specimens. Filamentous hyphal form was dominant in 5-day specimens. Most of the hyphae and blastospores showed penetration into dentinal tubules. The body of germinating mother cells and hyphae demonstrated collapsed cell walls as a result of vacuole formation.

CONCLUSIONS

With this invasive affinity to dentinal structures, C. albicans may be considered a dentinophilic microorganism.

Candidal infection of the gingiva in HIV-infected persons

Gingival biopsies were taken from 27 HIV (human immunodeficiency virus)-seropositive persons with gingivitis or periodontitis and 16 HIV-seronegative persons with periodontitis. Sections were stained with hematoxylin and eosin or periodic acid-Schiff. Candidal hyphae and pseudohyphae were found in the parakeratinized oral epithelium in 7 specimens from the HIV-infected patient group such specimen. No fungal invasion was found in any of the biopsies from the HIV-seronegative persons. Candidal invasion was significantly more frequent (P < 0.05) in patients with a confirmed history of necrotizing periodontal diseases (5/9) than in patients without known episodes of such diseases (3/18). The most prominent histopathologic changes observed in connection with candidal invasion comprised polymorphonuclear leucocyte infiltration of the oral gingival epithelium and numerous mitoses, some of which were located suprabasally. It is suggested that Candida albicans may contribute to the development of necrotizing periodontal diseases in HIV-infected persons.

Prevention of infective endocarditis: a review of the medical and dental literature

This paper is a review of what is presently known about the cause and prevention of infective endocarditis. Systemic antibiotics alone are not always enough for an effective prevention of infective endocarditis. Non-streptococcus bacteria frequently found in the periodontal pocket are now reported as causing infective endocarditis; these bacteria are not uniformly susceptible to the antibiotics recommended for prophylaxis. Animal studies indicate that periodontal disease does increase the incidence of infective endocarditis and that the number of microbes entering the blood stream may not be as important in the production of infective endocarditis as other qualities, such as the microbe's ability to adhere. Antibiotics may affect the ability of a microorganism to adhere to tissues of the heart, but this association is yet unclear and may vary with the antibiotic and species of bacteria. Reduction of inflammation of the periodontal tissues is of the utmost importance in the prevention of infective endocarditis; however, mouthrinses have a very limited effect in a periodontal pocket of more than 3 mm in depth and irrigation of a periodontal pocket may create a dangerous bacteremia. Nevertheless, in addition to systemic antibiotics, local antimicrobial agents followed by routine dental treatment and maintenance show promise as an effective means for the prevention of infective endocarditis. Future research in the prevention of infective endocarditis should include placement of antimicrobials in the periodontal pocket and systemic agents that reduce platelet adhesion. The suggestions presented in this review are only recommendations for further research and are not to be construed as a substitute for the current guidelines.

Anaerobiosis and serum promote mycelium formation by Candida albicans in colonies on TSBV agar

Following long-term periodontal treatment with tetracycline a superinfection with Candida may arise. The reduced environment and the serum transudate of the periodontal pocket may promote such infection. The present in vitro study was performed to ascertain whether yeast-mycelium transformation in a fresh periodontal isolate was promoted under anaerobic conditions and in the presence of serum. C. albicans, isolated from a patient with tetracycline-treated refractory periodontitis, was cultured anaerobically or aerobically on TSBV or Sabouraud's dextrose agar at 29 degrees C or 37 degrees C for 72 h, with the pH of the medium being 5.6 or 7.2. TSBV medium was also tested with its horse serum or yeast extract removed. Mycelial growth was recorded visually and by stereo and scanning electron microscopy. Anaerobic culture at 29 degrees C or 37 degrees C on TSBV provided abundant mycelium at both pHs. After aerobic culture the mycelial phase was less pronounced and more abundant at pH 7.2 than at 5.6. TSBV without serum or yeast extract yielded more mycelium after anaerobic than after aerobic culture, although less than when both components were included. Sabouraud's medium provided sparse mycelium after anaerobic culture irrespective of the pH, and no mycelium after aerobic culture.

Clinical-mycologic diagnosis of oral yeast infections

Conventional oral specimens for recovery of yeasts are swabs and smears. Oral rinses and imprint/impression cultures can also be used. Yeasts grow well at room temperature and may multiply in specimens under transport. Direct smears examined for blastospores, hyphae, and inflammatory cells ensure rapid presumptive diagnosis. Fungal identification requires culture, preferably on different media and at different temperatures to ensure recognition of all species present. YM agar supplemented with 0.01% aniline enables detection of Candida albicans and C. parapsilosis on primary plates through fluorescence. Microstix-Candida or Oricult-N slides can be read after culture at room temperature. Histologic sections for demonstration of yeasts require periodic acid-Schiff, Gridley, or Gomori's methenamine silver staining. Fungiqual staining enables non-specific diagnosis, also of rare oral mycoses, within 30 min, through fluorescence. Calcofluor white is even faster (less than 30 sec). Specific antibodies labeled with fluorescent stain enable more precise mycologic diagnosis. Mycologic findings should be interpreted together with clinical findings.

Scanning electron microscopic examination of pocket wall epithelium and associated plaque in localized juvenile periodontitis

The purpose of this investigation was to describe the morphologic characteristics of epithelial-associated plaque in periodontal pockets of patients with localized juvenile periodontitis (LJP). 25 tissue specimens obtained from 10 adolescent patients were examined by scanning electron microscopy. Specimens were evaluated to determine the following specific features: (1) distribution of microbial colonies on the epithelial surface; (2) topographic features of pocket epithelium associated with microbial colonies; and (3) the predominante microbial morphologic types comprising the colonies. Observations made during this investigation revealed the following. (1) The surface epithelium in the coronal one-third of the pocket wall was essentially healthy in appearance and exhibited no distinct microbial colonies or unusual topographic features. (2) The surface epithelium in the middle one-third area featured randomly-dispersed microbial colonies consisting of 3 major morphotypes: cocci, bacilli and coccobacilli. Also in this zone, there was morphologic evidence of microbial penetration of the epithelial barrier along intercellular spaces. (4) The apical one-third zone was characterized by lymphocytic infiltration, epithelial cavitation and ulcerations, and singular organisms entrapped in fibrin meshworks. There were no distinct microbial colonies in this zone, although individual spirochetes, fusiforms, filamentous organisms, and short and long rods were observed.