Isolation of Candida dubliniensis from denture wearers.
ABSTRACT Candida albicans is considered the most important Candida species able to cause oral infections in denture wearers. In recent years, Candida dubliniensis has emerged as a pathogenic yeast in humans. The close phenotypic similarities of C. albicans and C. dubliniensis have led to the misidentification of these species. In this work, our aim was to verify through PCR the presence of C. dubliniensis in palate and maxillary denture samples from 112 denture wearers presenting with or without denture-related stomatitis (DRS). C. dubliniensis was isolated at low rates from both palate (5.3 % and 10.7 %) and maxillary denture (5.3 % and 8.9 %) samples from wearers regardless of the presence of the disease. However, when C. dubliniensis was detected in individuals with DRS, it was always associated with C. albicans. In addition, our results showed that C. albicans was the most commonly identified candidal species in maxillary denture and hard palate samples from DRS patients (78.5 % and 89.2 %, respectively) as well as from controls (31.2 % and 28.5 %, respectively). In conclusion, C. dubliniensis was detected in the oral environment of denture wearers. The association of C. dubliniensis with C. albicans occurred in approximately 10 % of the DRS cases.
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ABSTRACT: Objectives: We aimed to investigate the effect of brief exposure to sub-cidal concentrations of nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate on the adhesion of oral Candida dubliniensis isolates to the surface of acrylic dentures. Methods: After determining the minimum inhibitory concentration of each drug, 20 oral isolates of C. dubliniensis were exposed to sub-cidal concentrations of the drugs for 1 h. The drugs were then removed by dilution, and the adhesion of the isolates to denture acrylic strips was assessed by an in vitro adhesion assay. Results: Compared to the controls, exposure to nystatin, amphotericin B, ketoconazole, fluconazole and chlorhexidine gluconate suppressed the ability of C. dubliniensis isolates to adhere to acrylic denture surfaces with a reduction of 74.68, 74.27, 57.31, 44.57 and 56.53% (p < 0.001 for all drugs), respectively. Conclusions: Brief exposure to sub-cidal concentrations of anti-mycotics suppressed the adhesion of C. dubliniensis oral isolates to acrylic denture surfaces. © 2014 S. Karger AG, Basel.Medical Principles and Practice 11/2014; 24(1). DOI:10.1159/000369019 · 1.11 Impact Factor
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ABSTRACT: This study evaluated the expression of pattern recognition receptors (PRRs) and activation factors associated with salivary and blood neutrophils from different aged patients diagnosed with Candida-related denture stomatitis (DS). Expression of neutrophil PRRs was determined by flow cytometry and immunofluorescence, and the levels of selected cytokines that influence immune activation were determined by ELISA. The salivary (but not the serum derived) neutrophils of individuals with DS were found to have an increased expression of CD69 regardless of the age of the patient compared to patients without DS. However, these salivary neutrophils had a lower expression of CD66b and CD64. Expression of TLR2 was lower on the salivary- and serum-derived neutrophils from elderly individuals compared to the neutrophils of younger subjects, regardless of whether the individual had DS. Salivary interleukin (IL)-4 was elevated in both of the elderly subject groups (with or without DS). Only elderly DS patients were observed to have increased serum IL-4 levels and reduced salivary IL-12 levels. Younger DS patients showed an increase in salivary IL-10 levels, and both the saliva and the serum levels of IFN-γ were increased in all of the younger subjects. Our data demonstrated that changes in both the oral immune cells and the protein components could be associated with DS. Furthermore, changes in the blood-derived factors were more associated with age than DS status.Experimental gerontology 07/2012; 47(9):741-8. DOI:10.1016/j.exger.2012.07.003 · 3.53 Impact Factor
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ABSTRACT: Candida species are considered the primary causative agents of denture stomatitis, but their role in colonization and disease in denture wearers remains undefined. In this study, we investigated risk factors associated with progression to Candida-related denture stomatitis in patients using complete dentures, and we genetically identified Candida isolates associated with disease and colonization. We recruited 114 retirement home residents for this study, from whom oral mucosa samples were collected and cultured following oral cavity exams. Morphologic analysis was used to identify potential yeast-positive cultures, which were then characterized further by RFLP analysis. C. albicans was the most frequently recovered species (61; 41.5%), followed by C. glabrata (27; 18.4%), and C. tropicalis (19; 12.9%). In addition, 16 isolates (10.9%) of C. dubliniensis were recovered, which was the first identification of this species in clinical samples from Iran. This study demonstrated a significant association between the duration of denture wear and oral candidiasis. Furthermore, we noted a high prevalence of C. dubliniensis in complete denture wearers.Medical mycology: official publication of the International Society for Human and Animal Mycology 02/2011; 49(2):208-11. DOI:10.3109/13693786.2010.507605 · 2.26 Impact Factor