Candida spp. adherence to oral epithelial cells and levels of IgA in children with orthodontic appliances

Adhesion and colonization of the oral cavity by Candida albicans is an initial step in candidosis. Orthodontic and other oral appliances seem to favor candidal presence. The aim of this work was to compare the presence of Candida species in saliva, their adherence to oral epithelial cells, and the levels of anti-C. albicans IgA in children with or without orthodontic appliances. This study included 30 children 5 to 12 years old (9.1 ± 1.7 years old) who were users of removable orthodontic devices for at least 6 months and 30 control children of similar ages (7.7 ± 1.5 years old). The presence of yeast species in the saliva was evaluated by microbiological methods. Candida species were identified using phenotypic methods. Anti-C. albicans IgA levels in saliva were analyzed by ELISA. The yeasts adhering to oral epithelial cells were assessed by exfoliative cytology. No statistically significant differences were observed for saliva yeast counts and anti-C. albicans IgA levels between the studied groups. Children with orthodontic devices exhibited more yeast cells adhering to oral epithelial cells and a higher percentage of non-albicans species relative to the control group. In conclusion, orthodontic appliances may favor the adherence of Candida to epithelial cells but do not influence the presence of these yeasts in saliva, and the levels of anti-C. albicans IgA do not correlate with yeast adherence or presence of Candida in the oral cavity

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

Effects of eating disorders on oral fungal diversity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oral colonization by yeasts in hiv-positive patients in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Susceptibility of Candida albicans and Candida dubliniensis to erythrosine- and LED-mediated photodynamic therapy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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.

Effect of different pre-irradiation times on curcumin-mediated photodynamic therapy against planktonic cultures and biofilms of Candida spp

Objectives: The aim of this study was to evaluate the effects of pre-irradiation time (PIT) on curcumin (Cur)-mediated photodynamic therapy (PDT) against planktonic and biofilm cultures of reference strains of Candida albicans, Candida glabrata and Candida dubliniensis. Materials and methods: Suspensions and biofilms of Candida species were maintained in contact with different concentrations of Cur for time intervals of 1, 5, 10 and 20 min before irradiation and LED (light emitting diode) activation. Additional samples were treated only with Cur, without illumination, or only with light, without Cur. Control samples received neither light nor Cur. After PDT, suspensions were plated on Sabouraud Dextrose Agar, while biofilm results were obtained using the XTT-salt reduction method. Confocal Laser Scanning Microscopy (CLSM) observations were performed to supply a better understanding of Cur penetration through the biofilms after 5 and 20 min of contact with the cultures. Results: Different PITs showed no statistical differences in Cur-mediated PDT of Candida spp. cell suspensions. There was complete inactivation of the three Candida species with the association of 20.0 μM Cur after 5, 10 and 20 min of PIT. Biofilm cultures showed significant reduction in cell viability after PDT. In general, the three Candida species evaluated in this study suffered higher reductions in cell viability with the association of 40.0 μM Cur and 20 min of PIT. Additionally, CLSM observations showed different intensities of fluorescence emissions after 5 and 20 min of incubation. Conclusion: Photoinactivation of planktonic cultures was not PIT-dependent. PIT-dependence of the biofilm cultures differed among the species evaluated. Also, CLSM observations confirmed the need of higher time intervals for the Cur to penetrate biofilm structures. © 2012 Elsevier Ltd. All rights reserved.

Hydroxyurea therapy in sickle cell anemia patients aids to maintain oral fungal colonization balance

Background: The aim of this study was to evaluate the frequency of Candida species and presence of lesions in the oral cavity of patients with sickle cell anemia (SS). Methods: The study included 30 patients diagnosed with sickle cell anemia and taking hydroxyurea for at least 90 days (SS/HU+); and 39 patients with sickle cell anemia and without hydroxyurea therapy (SS/HU-). Two control groups were constituted by healthy individuals matched to the test groups in age, gender, and oral conditions (C/HU+ for SS/HU+ and C/HU- for SS/HU-). Oral clinical examination and anamnesis were performed. Yeasts were collected by oral rinses and identified by API system. Antifungal susceptibility evaluation was performed according to the CLSI methodology. Data obtained for microorganisms counts were compared by Student's t test (SS/HU+ vs. C/HU+ and SS/HU- vs. C/HU-) using MINITAB for Windows 1.4. Significance level was set at 5%. Results: No oral candidosis lesions were detected. Significant differences in yeasts counts were observed between SS/HU- group and the respective control, but there were no differences between SS/HU+ and C/HU+. Candida albicans was the most prevalent species in all groups. Candida famata was observed both in SS and control groups. Candida dubliniensis, Candida glabrata, Candida krusei, Candida tropicalis, Candida pelliculosa, and Candida parapsilosis were observed only in SS groups. Most strains were susceptible to all antifungal agents. Conclusion: Hydroxyurea therapy seems to decrease candidal counts and resistance rate in sickle cell anemia patients. However, further studies should be conducted in the future to confirm this finding. Hydroxyurea therapy in sickle cell anemia patients maintains fungal species balance in oral cavity. © 2013 John Wiley & Sons A/S.

Efetividade da terapia fotodinâmica mediada pela curcumina em Candida spp

Pós-graduação em Reabilitação Oral - FOAR

Interações entre diferentes espécies de Candida na candidose experimental em modelos de invertebrados e vertebrados

Pós-graduação em Biopatologia Bucal - ICT

Identification of Candida Spp. In Patients with Denture Stomatitis: Relationship with Gender, Age, Time of Denture use and Newton’s Classification

Epidemiological researches are important to understand the distribution and etiology of oral diseases. The actual researches that show the relationship between patient ages, denture status and denture stomatitis are scarce. So, the aim of this study was to identify of Candida spp. in patients with Denture Stomatitis (DS) and to correlate with gender, age, time of denture use and Newton’s classification. 204 complete denture patients (46 males and 158 females) were selected. DS was classified according to Newton’s classification and it was related to gender, age and time of denture use. Samples from the palatal mucosa and the surface of the upper denture of patients with DS were evaluated using PCR test for identification of Candida species. T-test, chisquare and Fisher’s exact tests were used for statistical analysis. DS was evidenced in 54.4% of the sample. According to gender 41.3% of the males and 58.3% females had the disease and the differences were statistically significant (p = 0.032). The type of DS was directly influenced by the time of denture use (p<0.001), but it was not significantly related to the age of the participants (p>0.05). C. albicans, C. tropicalis, C. glabrata, C. krusei and C. dubliniensis were identified by PCR test. DS is more prevalent in women and the prevalence of DS was influenced by the time of denture use (years). C. albicans was identified as the most frequent specie in patients with DS.

In vitro antifungal susceptibility of candida albicans isolates from patients with chronic periodontitis and diabetes

Alterations that lead to deficiency of the immune system, such as diabetes mellitus, may promote proliferation of Candida albicans and selection of strains which have greater ability to adhere and to penetrate the host tissues. Recent studies indicate an increase of the antifungal resistance of C. albicans isolates in periodontal pockets, suggesting that the oral cavity could be a reservoir of resistant yeast to antifungal agents. Moreover, oral cavity can act as a reservoir of certain pathogens that may cause systemic infections. The periodontal pocket is an ecological niche suitable to host microorganisms that could act as opportunistic pathogens. The aim of this study is to contribute to the understanding of resistance to conventional antifungal against C. albicans isolates from patients with periodontitis and diabetes. The determination of the minimal inhibitory concentrations (MIC) was evaluated according to M27S3 of the CLSI (2008), with modifications. The results showed that 48.8% of the studied strains were resistant to one or more antifungals and 6.6% were resistant to fluconazole and voriconazole. These results suggest an increasing resistance to conventional antifungal agents among Candida species, suggesting that the oral cavity could host pathogen fungi.

Terpinen-4-ol: estudo do efeito sinérgico/aditivo, adesão em co-cultura e alteração dos fatores de virulência sobre Candida spp

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Usnic Acid on Candida orthopsilosis and C. parapsilosis

The activity of usnic acid against Candida orthopsilosis and Candida parapsilosis on planktonic and biofilm conditions was investigated by using a broth microdilution and microplate methods. Potent in vitro activities against different Candida species were obtained. The metabolic activity of sessile cells of C. parapsilosis complex was reduced by 80% at four times the 80% inhibitory concentration. The in vitro studies support further efforts to determine whether usnic acid can be used clinically to cure patients with Candida infections.

New antimicrobial therapies used against fungi present in subgingival sites-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. The treatment of periodontal disease includes scaling and root planning (SR?) associated with proper oral hygiene. However, some patients may have negative responses to different therapeutic procedures, with a continuous loss of insertion, so the use of antimicrobials is needed as an adjuvant to SRP treatment. The use of a broad-spectrum antibiotic, such as tetracycline and metronidazole, as an aid in periodontal treatment has also been a factor for the development of superinfections by resistant bacteria and Candida species, even in patients with HIV. In the dental practice, the most commonly used antifungals are nystatin and fluconazole. However, the introduction of new drugs like the next generation of azoles is essential before the onset of emergent species in periodontal disease. Plants are good options for obtaining a wide variety of drugs. This alternative could benefit a large population that uses plants as a first treatment option. Plants have been used in medicine for a long time and are extensively used in folk medicine, because they represent an economic alternative, are easily accessible and are applicable to various diseases. Herein, we briefly review the literature pertaining the presence of Candida sp. in periodontal pockets, the conventional antifungal resistance and new therapies that include natural antifungal agents are reviewed. (C) 2011 Elsevier Ltd. All rights reserved.