Quantification and Pathogenicity of Candida albicans in Denture-Wearing and Nondenture-Wearing Elderly

Acanthus ilicifolius Methanolic Extract for Oral Candidiasis Treatment through Tongue Epithelial STAT3 and Cell Death Evaluation

OBJECTIVES

 This study aimed to evaluate the effects of topical application of Acanthus ilicifolius methanolic extract on signal transducer and activator of transcription 3 (STAT3) expression and tongue epithelial cell death caused by oral candidiasis under immunosuppressive conditions.

MATERIALS AND METHODS

 To obtain the oral candidiasis model, 20 healthy male Rattus norvegicus (Wistar) rats were administered oral dexamethasone and tetracycline for 14 days and oral candidiasis was induced with Candida albicans (ATCC-10231) 1 McFarland. They were then randomized into four groups-immunosuppression (K-), oral candidiasis (K + ), nystatin treatment (P1), and 20% A. ilicifolius methanolic extract treatment (P2) and were treated for 14 days. Histological analyses of cell death and candida invasion and immunohistochemical analysis of STAT3 in epithelial cells were performed.

STATISTICAL ANALYSIS

 Epithelial cell death data were analyzed using one-way analysis of variance (ANOVA) and the post hoc Games-Howell test (p < 0.05) and STAT3 expression with one-way ANOVA and the post hoc least significant difference test (p < 0.05).

RESULTS

 Cell death was significantly different between K- and K+ and between K+ and P1 and P2 (p < 0.05); there were no significant differences between K- and P1 and P2 and between P1 and P2 (p > 0.05). STAT3 expression was significantly different between K- and P1 and P2 and between K+ and P1 and P2 (p < 0.05), but there were no significant differences between K+ and K- and between P1 and P2 (p > 0.05).

CONCLUSION

 Topical administration of A. ilicifolius methanol extract increased STAT3 expression and decreased tongue epithelial cell death caused by oral candidiasis.

Association Between Candida albicans and COVID-19 in Complete Denture Wearers: An Observational Study

Introduction The phenomenon of coronavirus disease 2019 (COVID-19)-related candidiasis is gaining increased attention and acknowledgment as an integral component of the severe consequences of COVID-19. The aim of the present study was to assess the association between Candida albicans and COVID-19 in complete denture wearers. Materials and methods An observational study was conducted on 45 complete denture wearers, who were divided into three groups as follows: Group 1, 15 subjects with mild to moderate COVID-19 infection; Group 2, 15 subjects with severe COVID-19 infection; and Group 3, 15 subjects without COVID-19 infection. Mean colony forming units (CFU) were observed on agar plates containing Sabouraud dextrose in the salivary samples of the participants. Analysis of variance, followed by post-hoc analysis by Tukey's test, was used to compare CFU between the groups. Pearson's correlation coefficient was used to study the correlation between variables. Results The highest average colony-forming units of Candida albicans were observed in Group 2, followed by Group 1, compared to the control group, and a significant (p<0.001) difference was found. A weak positive correlation was found between the age of the patients and the duration of denture usage, as well as between age and the counts of Candida albicans in Groups 1 and 3. This correlation was more pronounced in Group 3. A strong positive correlation was observed in all groups between the Candida albicans count and the duration of denture usage by the patients. Conclusion The association between Candida albicans and denture wear was compounded by the presence of COVID-19. Consequently, the timely identification of Candida albicans infection in patients with COVID-19 is important to establish more efficacious approaches for antifungal treatment and prophylactic interventions.

Effect of Chitosan and Acrylic Acid Addition to Acrylic Resin on Porosity and Streptococcus mutans Growth in Denture Base

OBJECTIVE

 This work aimed to determine the effect of adding chitosan and acrylic acid to acrylic resin denture base on the porosity of the material and the growth of Streptococcus mutans.

MATERIALS AND METHODS

 This study is an experimental laboratory research. Samples were divided into the following three groups (n = 10): group 1 was the control group, group 2 was the acrylic resin mixture with 1% chitosan and acrylate acid, and group 3 was the acrylic resin mixture with 2% chitosan and acrylate acid. S. mutans growth was tested using the dilution method, and porosity was examined using an optical microscope. Data were calculated by one-way analysis of variance (p < 0.05) and correlation analysis.

RESULTS

 The acrylic resin added with 2% chitosan and acrylic acid showed pores with an almost spherical shape and the smallest size. Significant difference (p < 0.05) was observed among all the groups. A positive and extremely strong correlation was found between porosity and S. mutans growth.

CONCLUSION

 Chitosan and acrylic acid at 1 and 2% concentrations can be added to acrylic resin to minimize the porosity of the denture base and reduce the growth of S. mutans. A less porous denture is associated with a low S. mutans growth rate.

Y, Efendi D, Razak FA. ACE2 expression in saliva of patients with COVID-19 and its association with Candida albicans and Aggregatibacter actinomycetemcomitans

Background: A relationship between oral microbiota and susceptibility to SARS-CoV-2 infection has been extensively studied. However, the relationship between oral commensal flora and expression of angiotensin-converting enzyme 2 ( ACE2) remains to be established. In this observational study, we collected saliva from patients with COVID-19 and evaluated the relationship between ACE2 expression and Candida albicans as well as with selected gram-negative bacteria ( Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Veillonella parvula). We investigated how this may be directly or indirectly involved in oral dysbiosis in patients with COVID-19.

Methods: We included 23 hospitalized patients admitted to Universitas Indonesia Hospital with PCR-confirmed COVID-19, with six healthy participants serving as controls. Saliva and tongue surface swabs were collected from patients with diabetes (DG) and without diabetes (NDG) and subject controls. Using quantitative PCR (qPCR) we assessed the mRNA expression of ACE2, the abundance of C. albicans, and the transcription levels of its biofilm-associated genes, agglutinin-like protein 3 ( ALS3), hyphal wall protein 1 ( HWP1), and yeast-form wall protein 1 ( YWP1). We also counted the relative proportion of the three selected gram-negative oral bacteria in saliva. All analyses were performed to determine the relationship between ACE2 expression and C. albicans and gram-negative bacteria.

Results:ACE2 mRNA expression was significantly higher in tongue swab samples than in saliva. However, no significant difference was observed between the patient groups. Conversely, DG patients had a significantly higher abundance of C. albicans in saliva compared to NDG patients and control group patients. The correlation and sensitivity/specificity relationship between ACE2 expression and C. albicans or the selected oral bacteria were also observed.

Conclusions: The data show that ACE2 expression can be detected in saliva of patients with COVID-19 and its association with C. albicans and gram-negative oral bacteria might contribute toward developing an oral dysbiosis based predictor for prognosis of COVID-19 severity.

Antifungal Susceptibility of Candida albicans Isolated from Tongue and Subgingival Biofilm of Periodontitis Patients

The subgingival biofilm, as the most complex microbial community, has been proven to be reservoir of Candida spp. The main concept of this study was to investigate if there is a difference between the sensitivity of Candida albicans (C. albicans) isolated from tongue and subgingival areas of periodontitis patients to antifungal agents. The aim of the study was to determine: (1) the distribution of different Candida species in the tongue and subgingival samples of periodontitis patients; (2) the susceptibility of Candida albicans strains from tongue and subgingival biofilm to the effects of commonly used antifungal agents: fluconazole, amphotericin B and itraconazole; (3) the correlation between the susceptibility of Candida albicans and clinical periodontal parameters. Tongue and subgingival biofilm samples of periodontitis subjects (N = 163) were examined. Susceptibility was tested when the same Candida species was isolated from both sites (17 subjects). Candida spp. were isolated in 23.3% of tongue and 21.5% of the subgingival samples. All isolates were susceptible to amphotericin B, while 64.71% of tongue and 52.94% of subgingival isolates were susceptible to fluconazole. A low frequency of itraconazole susceptibility was observed for tongue (17.64%) and subgingival isolates (11.76%). The correlations between full-mouth plaque score and Minimal Inhibitory Concentration (MIC) for tongue isolates were strongly positive for all antimycotics. Positive correlation was also observed between moderate periodontal destruction and MICs for tongue and subgingival isolates. The susceptibility of C. albicans to antifungals correlate with oral hygiene and moderate periodontal destruction. There is no difference in antifungal susceptibility between tongue and subgingival isolates.

Validation of RNA Aptamer Probes to Image Candida albicans in Paraffin-Embedded Sections of Wistar Rat Tongue

Objective  This study aimed to validate the use of Ca-apt-1, an RNA aptamer, that we generated previously as a probe for immunostaining of Candida albicans in rat tongue paraffin-fixed tissue sections

Material and Methods  The performance of Ca-apt-1 as a detector molecule was compared with that of anti- C. albicans polyclonal antibody (PcAb), which was used as a positive control. Immunostaining images were visualized by light microscopy and were analyzed by using ImageJ software.

Results  Microscopic results demonstrated that Ca-apt-1 specifically recognized and immunostained C. albicans cells of rat tongue candidiasis, with a specificity comparable to that of PcAb. ImageJ analysis showed that the area (pixels) detected by Ca-apt-1 was wider than that detected by the antibody. This indicates that the binding affinity of Ca-apt-1 toward C. albicans was better than that of PcAb on paraffin-embedded tissues.

Conclusion  This study demonstrates that Ca-apt-1 can be used as a probe for immunostaining of fixed tissue sections for oral candidiasis diagnosis.

Quality of Life, Satisfaction, Occlusal Force, and Halitosis after Direct and Indirect Relining of Inferior Complete Dentures

Objective  The aim of this study was to compare the direct relining technique with the indirect relining technique in relation to quality of life, satisfaction with the relining, occlusal force, and halitosis of users of acrylic complete dentures.

Materials and Methods  Twenty bimaxillary edentulous individuals were selected. They had to use the same pair of complete dentures for a minimum of 1 year and a maximum of 5 years. The subjects were randomly divided in groups of direct relining and indirect relining of the inferior denture ( n = 10). Both groups received the same silicone-based relining. The clinical tests verified the quality of life (Oral Health Impact Profile in edentulous individuals), the satisfaction with the relining, the occlusal force, and halitosis. The tests (halitosis and occlusal force) were performed initially (before the relining), immediately after the relining, and 30, 60, 90, and 180 days after the relining. The questionnaires (quality of life and satisfaction with the relining) were performed initially (before the relining), and 30, 60, 90, and 180 days after the relining.

Statistical Analysis  Analysis of variance and the Tukey test were used ( p < 0.05).

Results  There was no statistical difference comparing the two techniques in all the evaluations ( p < 0.05). There was a significant statistical difference for the factor of time in all clinical tests for each relining technique ( p < 0.05). The quality of life and satisfaction with the relining increased significantly 30 days after the relining when compared with the initial time point, for both techniques ( p < 0.05). The occlusal force increased significantly after 90 and 180 days when compared with the initial time point, for both techniques ( p < 0.05). Halitosis decreased significantly immediately after the relining when compared with the initial time point, for both techniques ( p < 0.05).

Conclusion  Independent of the relining technique used, there was an increase in the quality of life, satisfaction with the relining, and occlusal force, as well as a reduction in the level of halitosis. Both techniques generated similar results and therefore can be options in clinical practice.

The Discrepancy between Clove and Non-Clove Cigarette Smoke-Promoted Candida albicans Biofilm Formation with Precoating RNA-aptamer

This study explores the influence of precoating aptamer (Ca-apt1) on C. albicans viability while the fungus was growing in the presence of exposing condensed cigarette smoke (CSC), prepared from clove (CCSC) and non-clove (NCSC) cigarettes, for 48 h. Using qPCR, we found that mRNA expression of adhesion-associated genes ( ALS3 and HWP1) was impaired by precoating C. albicans yeast cells with the aptamer. Conversely, the gene transcription was upregulated when aptamer-uncoated yeast was pre-treated with either CSC. In addition, by analysing the result of MTT ([3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide] assay, we found that the presence of added CCSC or NCSC in growth medium for 48 h was significantly enhanced C. albicans biofilm development. However, the presence of precoated aptamer was significantly impaired biofilm development accelerated by the NCSC. The inhibitory effect of the Ca-apt1 was not dependent on the precoated aptamer (1ng/μL and 10 ng/μL). Interestingly, we noted that the enhancer effect of treated CCSC was no longer effective when the yeast had been precoated with 10 ng/μL aptamer tested. Additionally, light microscopy analysis revealed that precoating aptamer alleviates morphological changes of C. albicans (from yeast to hypha formation) that are enhanced by adding CCSC or NCSC in the growth medium.

In conclusion, these results suggest that administration on Ca-ap1 exhibits a significant protective effect on CSC-induced biofilm formation by C. albicans.