Pathogenesis and treatment of oral candidosis

Structure-activity relationship and biofilm formation-related gene targets of oleanolic acid-type saponins from Pulsatilla chinensis against Candida albicans

In the course of our investigations of antifungal natural products, the structure-activity relationship and antifungal activities of oleanolic acid-type saponins (1-28) from Pulsatilla chinensis against human and plant pathogenic fungi were elucidated. The analysis of structure-activity relationship of oleanolic acid-type saponins showed that the free carboxyl at C-28 was essential for their antifungal activities; the free hydroxyl group at the C-23 site of oleanolic acid-type saponins played a crucial role in their antifungal activities; the oligosaccharide chain at C-3 oleanolic acid-type saponins showed significant effects on antifungal efficacy and a disaccharide or trisaccharide moiety at position C-3 displayed optimal antifungal activity. The typical saponin pulchinenoside B3 (16, PB3) displayed satisfactory antifungal activity against human and plant pathogenic fungi, especially, C. albicans with an MIC value of 12.5 μg/mL. Furthermore, PB3 could inhibit the biofilm formation of C. albicans through downregulating the expression of the integrated network of biofilm formation-associated transcription factors (Bcr1 Efg1, Ndt80, Brg1, Rob1 and Tec1) and adhesion-related target genes (HWP1, ALS1, and ALS3). Meanwhile, we found that PB3 could effectively destroy the mature biofilm of C. albicans by the oxidative damage and inducing mitochondria-mediated apoptosis in cells.

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

Complex metal nanostructures represent an exceptional category of materials characterized by distinct morphologies and physicochemical properties. Nanostructures with shape anisotropies, such as nanorods, nanostars, nanocages, and nanoprisms, are particularly appealing due to their tunable surface plasmon resonances, controllable surface chemistries, and effective targeting capabilities. These complex nanostructures can absorb light in the near-infrared, enabling noteworthy applications in nanomedicine, molecular imaging, and biology. The engineering of targeting abilities through surface modifications involving ligands, antibodies, peptides, and other agents potentiates their effects. Recent years have witnessed the development of innovative structures with diverse compositions, expanding their applications in biomedicine. These applications encompass targeted imaging, surface-enhanced Raman spectroscopy, near-infrared II imaging, catalytic therapy, photothermal therapy, and cancer treatment. This review seeks to provide the nanomedicine community with a thorough and informative overview of the evolving landscape of complex metal nanoparticle research, with a specific emphasis on their roles in imaging, cancer therapy, infectious diseases, and biofilm treatment. This article is categorized under: Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease Diagnostic Tools > Diagnostic Nanodevices.

Anti-Candida activity and biocompatibility of silver nanoparticles associated with denture glaze: a new approach to the management of denture stomatitis

The association of silver nanoparticles (AgNps) to sealant agent Palaseal® can be a promising alternative for complete denture wearers who may develop denture stomatitis (DS). The study aimed to evaluate the anti-Candida and biocompatible potential of silver nanoparticles synthesized by three routes associated with denture glaze to prevent and/or treat oral candidiasis. Surface acrylic resin specimens were treated with different associations of glaze with AgNps (VER+AgUV, VER+AgTurk and VER+AgGm). As controls, specimens were treated with glaze+nystatin (VER+Nyst), glaze only (VER) or submerged in PBS (PBS). Afterwards, Candida albicans biofilm was developed for 24 h, 15 d and 30 d. Subsequently, the biofilm was quantified by CFU/mL, XTT assay and confocal laser scanning microscopy. Fibroblasts were submitted to conditioned medium with the same associations for 24, 48 and 72 h and LIVE/DEAD® viability test was carried out. Regardless of the period, there was a significant reduction (p < 0.01) of viable fungal cells load, as well as inhibition of fungal metabolic activity, in specimens treated with glaze+AgNps associations, compared to VER and PBS. The anti-Candida effects of the associations were similar to the VER+Nyst group, with emphasis on VER+AgGm, which showed the highest percentage values of non-viable fungal cells maintained over time. The associations did not prove toxicity to fibroblasts. The AgNps exerted antimicrobial activity against C. albicans biofilms and are biocompatible. The most effective results were achieved with the association of glaze+silver nanoparticles synthesized by the green chemistry method (AgGm), proving to be an innovative alternative in the management of DS.

Quinalizarin as a potential antifungal drug for the treatment of Candida albicans fungal infection in cancer patients

This study aims to analyze the antifungal properties of quinalizarin, a plant-derived compound with proven anticancer effects. Quinalizarin exhibited antifungal activity against opportunistic pathogenic Candida species and Geotrichum capitatum. The treatment with this anthraquinone reduced hyphal growth, inhibited biofilm formation, and damaged mature Candida albicans biofilms. Real-time RT-PCR revealed that quinalizarin downregulated the expression of hyphae-related and biofilm-specific genes. The flow cytometry method used in the study showed that both apoptosis and necrosis were the physiological mechanisms of quinalizarin-induced C. albicans cell death, depending on the dose of the antifungal agent. A further study revealed an increase in the levels of intracellular reactive oxygen species and alterations in mitochondrial membrane potential after treatment with quinalizarin. Finally, quinalizarin was found to have low toxicity in a hemolytic test using human erythrocytes. In conclusion, we have identified quinalizarin as a potential antifungal compound.IMPORTANCEThis article is a study to determine the antifungal activity of quinalizarin (1,2,5,8-tetrahydroxyanthraquinone). Quinalizarin has potential antitumor properties and is effective in different types of tumor cells. The aim of the present study was to prove that quinalizarin can be used simultaneously in the treatment of cancer and in the treatment of intercurrent fungal infections. Quinalizarin was identified as a novel antifungal compound with low toxicity. These results may contribute to the development of a new drug with dual activity in the treatment of cancer-associated candidiasis.

Phytochemical profile and antimicrobial activity of essential oils from two Syzygium species against selected oral pathogens

BACKGROUND

The genus Syzygium (Myrtaceae) comprises several essential oil-rich species that are utilized traditionally for treating tooth infections and toothache. The current study aimed to extract essential oils (EOs) from the leaves of Syzygium samarangense and Syzygium malaccense cultivated in Egypt for the first time and screen their antimicrobial potential against oral-related pathogens.

METHODS

The intended EOs were extracted using hydrodistillation (HD) by boiling fresh leaves with distilled water; supercritical fluid (SF) by extracting the dried leaves using supercritical CO2 at 40 °C and 150 bar; and the headspace (HS) in which the fresh leaves were heated in a glass vial and the vaporized aroma were analyzed. The volatile constituents were analyzed using GC/MS and identified by comparing the experimental Kovats' retention indices with the literature. The antimicrobial activity was assessed against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Candida albicans using agar diffusion, microwell dilution, and biofilm formation assays. Statistical significance (p < 0.05) was determined by applying one-way ANOVA and Duncan's post hoc test.

RESULTS

The yield of the extracted EOs differs between the applied methods, and the SF approach harvested the maximum (0.52-0.46%). The GC-MS analysis of SF EOs revealed a discrepancy between the two species. Since S. malaccense showed an abundance of hydrocarbons represented mainly by squalene (60.60%), S. samarangense was deemed to have oxygenated sesquiterpenes exemplified in globulol (52.09%). On the other side, the HD and HS EOs were sequentially comparable, while differed in the percentage of their majors. γ-terpinene (33.06%) pioneered the HS-derived aroma of S. malaccense, while S. samarangense was abundant with α-pinene (30.18%). Concurrently, the HD EOs of S. malaccense and S. samarangense were commonly denoted by caryophyllene oxide (8.19%-18.48%), p-cymene (16.02%- 19.50%), and γ-terpinene (12.20%-17.84). Ultimately, both species EOs exhibited broad-spectrum antimicrobial potential, although the HD EO was more potent than the SF EO. The HD EOs of both species potently inhibited the growth of E. coli (MIC 3.75 µL/mL) and suppressed C. albicans biofilm formation by 83.43 and 87.27%, respectively. The SF-EOs efficiently suppressed the biofilm formation of Gram-positive bacteria by 76.45%-82.95%.

CONCLUSION

EOs extracted from both species by different methods possessed a unique blend of volatile components with broad-spectrum antimicrobial activity. They were promoted as bioactive hits for controlling oral infections, however further investigations concerning their safety in clinical settings are needed.

Investigating the role of Candida albicans as a universal substrate for oral bacteria using a transcriptomic approach: implications for interkingdom biofilm control?

Candida albicans is frequently identified as a colonizer of the oral cavity in health and has recently been termed a "keystone" commensal due to its role on the bacterial communities. However, the role that C. albicans plays in such interactions is not fully understood. Therefore, this study aimed to identify the relationship between C. albicans and bacteria associated with oral symbiosis and dysbiosis. To do this, we evaluated the ability of C. albicans to support the growth of the aerobic commensal Streptococcus gordonii and the anaerobic pathogens Fusobacterium nucleatum and Porphyromonas gingivalis in the biofilm environment. RNA-Sequencing with the Illumina platform was then utilized to identify C. albicans gene expression and functional pathways involved during such interactions in dual-species and a 4-species biofilm model. Results indicated that C. albicans was capable of supporting growth of all three bacteria, with a significant increase in colony counts of each bacteria in the dual-species biofilm (p < 0.05). We identified specific functional enrichment of pathways in our 4-species community as well as transcriptional profiles unique to the F. nucleatum and S. gordonii dual-species biofilms, indicating a species-specific effect on C. albicans. Candida-related hemin acquisition and heat shock protein mediated processes were unique to the organism following co-culture with anaerobic and aerobic bacteria, respectively, suggestive that such pathways may be feasible options for therapeutic targeting to interfere with these fungal-bacterial interactions. Targeted antifungal therapy may be considered as an option for biofilm destabilization and treatment of complex communities. Moving forward, we propose that further studies must continue to investigate the role of this fungal organism in the context of the interkingdom nature of oral diseases.

Evaluation of the Antifungal Effect of Rhus verniciflua Stokes Extract for Oral Application Potential

Background and Objectives: This study confirms the possibility of using Rhus verniciflua Stokes (RVS) extract as a natural treatment for oral candidiasis. Materials and Methods: RVS was extracted with 70% ethanol to examine the antioxidant activity through polyphenol, flavonoid content, and DPPH (1,1-diphenyl-2-picrylhydrazyl). To evaluate the antifungal effect against Candida albicans (C. albicans; KCTC 7965/ATCC 10231) and evaluate the stability of RVS, a water-soluble tetrazolium salt (WST-1) assay was performed in human keratinocytes (HaCaT). Results: The findings revealed that RVS extract has fairly high antioxidant activity. The clear zones of the RVS extract against C. albicans increased in diameter due to the inhibition of fungal growth at higher concentrations. Treatment with the 1.25 mg/mL RVS extract had a more than 99% antifungal effect against C. albicans, and the 20 mg/mL RVS extract had a 100% antifungal effect. The WST-1 assay showed that the RVS extract induced low cell viability in the HaCaT cells, which inhibited their proliferation, and the RVS extract is also toxic to normal cells. Conclusions: Although the RVS extract with high antioxidant activity showed clear antifungal activity against C. albicans, it exhibited a low survival rate. Therefore, the development of a safe natural antibiotic is necessary.

Denture Stomatitis and Candida albicans in the Indian Population: A Systematic Review and Meta-Analysis

Denture stomatitis (DS), a common oral condition among denture wearers, is frequently associated with Candida albicans (C. albicans) colonization. This systematic review and meta-analysis aimed to provide a comprehensive assessment of DS prevalence and its relationship with C. albicans in the Indian population. We conducted a thorough search of multiple databases for studies without any limitation to the publication timeframe, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were assessed for quality and included in the meta-analysis. Data regarding DS prevalence, risk factors, and C. albicans colonization were extracted and analyzed. A total of four studies comprising 415 participants were included in the review. The overall odds ratio (OR) and risk ratio (RR) for the prevalence of C. albicans in DS patients were 0.75 (95% CI 0.56 to 0.99) and 0.83 (95% CI 0.70 to 1.00), respectively, indicating a statistically significant association between DS and C. albicans colonization. Several risk factors, including continuous denture wearing, advanced denture age, poor denture hygiene, and high sugar intake, were identified as contributing to DS development. This systematic review and meta-analysis highlight the substantial burden of DS and its association with C. albicans colonization in the Indian population. The findings emphasize the need for comprehensive oral care, improved denture hygiene, dietary counseling, and interventions to enhance salivary flow in denture wearers to mitigate the risk of DS. These insights can inform healthcare providers and policymakers to develop targeted strategies for DS prevention and management in India. Furthermore, this study emphasizes the significance of oral health awareness and preventive strategies in groups with a high frequency of denture usage in a larger population.

In Vitro Evaluation of Candida albicans Adhesion on Heat-Cured Resin-Based Dental Composites

Microbial adhesion on dental restorative materials may jeopardize the restorative treatment long-term outcome. The goal of this in vitro study was to assess Candida albicans capability to adhere and form a biofilm on the surface of heat-cured dental composites having different formulations but subjected to identical surface treatments and polymerization protocols. Three commercially available composites were evaluated: GrandioSO (GR), Venus Diamond (VD) and Enamel Plus HRi Biofunction (BF). Cylindrical specimens were prepared for quantitative determination of C. albicans S5 planktonic CFU count, sessile cells CFU count and biomass optical density (OD570 nm). Qualitative Concanavalin-A assays (for extracellular polymeric substances of a biofilm matrix) and Scanning Electron Microscope (SEM) analyses (for the morphology of sessile colonies) were also performed. Focusing on planktonic CFU count, a slight but not significant reduction was observed with VD as compared to GR. Regarding sessile cells CFU count and biomass OD570 nm, a significant increase was observed for VD compared to GR and BF. Concanavalin-A assays and SEM analyses confirmed the quantitative results. Different formulations of commercially available resin composites may differently interact with C. albicans. The present results showed a relatively more pronounced antiadhesive effect for BF and GR, with a reduction in sessile cells CFU count and biomass quantification.

Medium-chain fatty acids as an alternative treatment for denture stomatitis in older people

OBJECTIVE

To determine the effect of medium-chain fatty acids (MCFA) on the severity of denture stomatitis (DS) and the counts of Candida spp. in older people (OP) wearing removable prostheses (RP).

MATERIALS AND METHODS

This randomized, controlled and triple-blind study included forty-three OP presenting DS. The control group was treated with 0.12% chlorhexidine (CHX) and the experimental group with MCFA, 2 × /day for 15 days. Intraoral examination and counts of Candida spp. were performed at 0, 7, and 15 days. The differences between both groups in the decrease of the severity of DS and the viability of Candida spp. were determined clinically and microbiologically, respectively.

RESULTS

OP carriers of RP treated with MCFA presented remission of the clinical signs of DS, but the Candida spp. counts only decreased significantly in the CHX-treated group at 7 days of treatment (p < 0.05). Besides, MCFA was shown to reduce the clinical signs of DS after the first week of application, while CHX after the second week.

CONCLUSIONS

The MCFA is effective in reducing the clinical signs of DS associated with oral candidiasis in subjects with RP. Both treatments showed a significant decrease in severity, for MCFA after the first week and for CHX two weeks after starting the corresponding treatment.

CLINICAL RELEVANCE

The MCFA is an effective, harmless, and accessible treatment alternative against DS, since it manages to reduce the severity of the lesion in the milder cases of DS in the oral mucosa of OP carriers of RP.

Recent Advances in Pharmaceutical Approaches of Antimicrobial Agents for Selective Delivery in Various Administration Routes

Globally, the increase of pathogenic bacteria with antibiotic-resistant characteristics has become a critical challenge in medical treatment. The misuse of conventional antibiotics to treat an infectious disease often results in increased resistance and a scarcity of effective antimicrobials to be used in the future against the organisms. Here, we discuss the rise of antimicrobial resistance (AMR) and the need to combat it through the discovery of new synthetic or naturally occurring antibacterial compounds, as well as insights into the application of various drug delivery approaches delivered via various routes compared to conventional delivery systems. AMR-related infectious diseases are also discussed, as is the efficiency of various delivery systems. Future considerations in developing highly effective antimicrobial delivery devices to address antibiotic resistance are also presented here, especially on the smart delivery system of antibiotics.

Palatal brushing for the treatment of denture stomatitis: A multicentre randomized controlled trial

PURPOSE

To determine the effectiveness of palatal brushing in the treatment of denture-related erythematous stomatitis (DES) in complete denture wearers.

METHODS

This two-parallel-arm RCT was conducted in three university clinics in Brazil, Canada, and Chile. Participants (n=77) were randomly allocated to receive (i) instructions for palatal brushing and standard oral/denture hygiene ("intervention"); or (ii) standard oral/denture hygiene instructions only ("control"). Data collection was carried out at the baseline and at 3 and 6 months after intervention. Outcomes included the magnitude of oral Candida carriage and the degree of inflammation of denture-bearing tissues. Groups were compared using generalized estimating equations and chi-square test (α=0.05).

RESULTS

Palatal inflammation levels were reduced significantly in the "intervention" compared to "control" group at 6 months (intervention: 70%, control: 40%; chi-square, p=0.04). There was no between-group significant difference in the Candida count from denture and palatal biofilms; however, a subgroup analysis restricted to baseline Candida carriers showed further reduction with the intervention at 6 months. No adversity was observed by trialist or reported by participants.

CONCLUSIONS

Including palatal brushing in oral instructions for denture wearers has positive impact on DES-related mucosal inflammation. Thus, our findings endorse the inclusion of palatal brushing in standard oral hygiene instructions to treat DES.

Anti-fungal efficacy of Miswak Extract (Salvadora Persica) and commercial cleaner against Candida albicans on heat cured polymethylmethacrylate denture base

AIM

The aim of the study was to compare the antifungal efficacy between commercial cleaner (Corega) and Miswak extract (Salvadora persica) against Candida albicans on heat cured Polymethyl methacrylate (PMMA) acrylic denture base resin.

MATERIALS AND METHODS

Forty-eight samples of heat cured PMMA acrylic denture base resin were fabircated in the study. The sterile acrylic resin specimens were immersed in standardized cell suspension of Candida albicans and incubated for 60 min at 370°C for cell adhesion and 2 h at 370°C for biofilm formation. After 24 h biofilm was evaluated by cell viability (CFUs) on SDA and cell counting of Candida albicans under light microscope at 400× magnification. The fungicidal effect of commercial cleaner and Miswak extract on Candida albicans biofilm was then evaluated by colony-forming units on SDA and cell counting under light microscope at 400× magnification.

RESULTS

Screening test agar disk-diffusion assay showed mean inhibitory zone of 3 mm for commercial cleaner as compared to Miswak extract, which showed mean inhibitory zone of 2 and 1 mm for different concentrations. Broth microdilution method showed 31 mg/ml MIC and 62.5 mg/ml Minimal Fungicidal Concentration (MFC) values for commercial cleaner as compared to Miswak extract that showed 125 mg/ml MIC and 250 mg/ml MFC values against Candida albicans. A significant difference (p < 0.05) was observed between pre and post treatment of both commercial cleaner and Miswak extract, for CFUs and cell count for Candida albicans.

CONCLUSION

Commercial denture cleaner (Corega) showed better antifungal (C albicans) activity than Miswak extract (Salvadora persica) on heat cured PMMA acrylic denture base resin.

Postoperative Pain Exacerbation After Adenotonsillectomy Due to Oral Candida Infection?

Post-tonsillectomy complications can include bleeding, dehydration, edema, airway obstruction, and infection. Oral candidiasis or thrush is a rare complication that can occur post-operatively. We describe a case of a 10-year-old female with oral candidiasis as a postoperative complication of bilateral adenotonsillectomy, presenting on postoperative day (POD) 7 for poor oral intake secondary to worsening odynophagia. A physical exam revealed an easily scrapable, white plaque located mainly over her surgical sites, tongue, and hard palate. Microscopic examination of tissue scrapings revealed pseudohyphae confirming the diagnosis of oral candidiasis. She was treated with seven days of topical nystatin therapy, including topical and systemic pain control with significant improvement of symptoms by POD 13 and complete resolution on POD 21.

Molecular Mapping of Antifungal Mechanisms Accessing Biomaterials and New Agents to Target Oral Candidiasis

Oral candidiasis has a high rate of development, especially in immunocompromised patients. Immunosuppressive and cytotoxic therapies in hospitalized HIV and cancer patients are known to induce the poor management of adverse reactions, where local and systemic candidiasis become highly resistant to conventional antifungal therapy. The development of oral candidiasis is triggered by several mechanisms that determine oral epithelium imbalances, resulting in poor local defense and a delayed immune system response. As a result, pathogenic fungi colonies disseminate and form resistant biofilms, promoting serious challenges in initiating a proper therapeutic protocol. Hence, this study of the literature aimed to discuss possibilities and new trends through antifungal therapy for buccal drug administration. A large number of studies explored the antifungal activity of new agents or synergic components that may enhance the effect of classic drugs. It was of significant interest to find connections between smart biomaterials and their activity, to find molecular responses and mechanisms that can conquer the multidrug resistance of fungi strains, and to transpose them into a molecular map. Overall, attention is focused on the nanocolloids domain, nanoparticles, nanocomposite synthesis, and the design of polymeric platforms to satisfy sustained antifungal activity and high biocompatibility with the oral mucosa.

No-ozone cold plasma can kill oral pathogenic microbes in H2O2-dependent and independent manner

To apply the sterilisation effect of low-temperature plasma to the oral cavity, the issue of ozone from plasma must be addressed. In this study, a new technology for generating cold plasma with almost no ozone is developed and is named Nozone (no-ozone) Cold Plasma (NCP) technology. The antimicrobial efficacy of the NCP against four oral pathogens is tested, and its specific mechanism is elucidated. The treatment of NCP on oral pathogenic microbes on a solid medium generated a growth inhibition zone. When NCP is applied to oral pathogens in a liquid medium, the growth of microbes decreased by more than 10⁵ colony forming units, and the bactericidal effect of NCP remained after the installation of dental tips. The bactericidal effect of NCP in the liquid medium is due to the increase in hydrogen peroxide levels in the medium. However, the bactericidal effect of NCP in the solid medium depends on the charged elements of the NCP. Furthermore, the surface bactericidal efficiency of the dental-tip-installed NCP is proportional to the pore size of the tips and inversely proportional to the length of the tips. Overall, we expect this NCP device to be widely used in dentistry in the near future.

Genetic Screening of Candida albicans Inactivation Mutants Identifies New Genes Involved in Macrophage-Fungal Cell Interactions

Candida albicans, an important fungal pathogen of humans, displays different morphologies, such as yeast, pseudo-hyphae and hyphae, which are recognized unequally by phagocytic cells of the innate immune response. Once C. albicans cells invade host tissues, immune cells such as macrophages are attracted to the site of infection and activated to recognize, engulf and kill the pathogen. We have investigated this fungal cell-macrophage interface by using high-throughput screening of the C. albicans GRACE library to identify genes that can influence this interaction and modify the kinetics of engulfment. Compared with the wild-type (WT) strain, we identified generally faster rates of engulfment for those fungal strains with constitutive pseudo-hyphal and hyphal phenotypes, whereas yeast-form-locked strains showed a reduced and delayed recognition and internalization by macrophages. We identified a number of GRACE strains that showed normal morphological development but exhibited different recognition and engulfment kinetics by cultured macrophages and characterized two mutants that modified interactions with the murine and human-derived macrophages. One mutant inactivated an uncharacterized C. albicans open reading frame that is the ortholog of S. cerevisiae OPY1, the other inactivated CaKRE1. The modified interaction was monitored during a 4 h co-culture. Early in the interaction, both opy1 and kre1 mutant strains showed reduced recognition and engulfment rates by macrophages when compared with WT cells. At fungal germ tube initiation, the engulfment kinetics increased for both mutants and WT cells, however the WT cells still showed a higher internalization by macrophages up to 2 h of interaction. Subsequently, between 2 and 4 h of the interaction, when most macrophages contain engulfed fungal cells, the engulfment kinetics increased for the opy1 mutant and further decreased for the kre1 mutant compared with Ca-WT. It appears that fungal morphology influences macrophage association with C. albicans cells and that both OPY1 and KRE1 play roles in the interaction of the fungal cells with phagocytes.

Prevalence and Antifungal Susceptibility Profile of Oral Candida spp. Isolates from a Hospital in Slovakia

Oral fungal infections are a worldwide healthcare problem. Although Candida albicans is still the most common yeast involved in the infections of oral cavity, non-Candida albicans Candida species (NCACs) have been highly related to these infections, particularly in older, immunosuppressed or patients with long exposure to antimicrobial drugs. The goal of this work was to perform a quick epidemiological and mycological study on the oral samples collected from a laboratory of a hospital in Slovakia, for 60 days. The samples’ identification was performed by Germ-tube formation test, CHROMID® Candida, Auxacolor 2, ID 32C automated method, and the antifungal susceptibility testing determined by E-test®. Results confirm that comparing with bacteria, yeasts still occur in the lower number, but there is a high rate of antifungal resistance (81.6%)—to, at least one drug—among the collected samples, particularly to azoles and 5′-FC, which is clinically noteworthy.

Comparison of complications during 1-year follow-up between remitting seronegative symmetrical synovitis with pitting edema syndrome and elderly-onset rheumatoid arthritis

Remitting seronegative symmetrical synovitis with pitting edema syndrome (RS3PE), a rheumatic disease affecting the elderly, responds well to corticosteroids; however, our RS3PE patients' corticosteroid therapy is longer than expected. Elderly-onset rheumatoid arthritis (EORA) patients are reported to be at a significantly increased risk for steroid-related side effects including cardiovascular diseases (CVDs). To clarify the complications during a 1-year follow-up in corticosteroid-treated RS3PE patients compared to EORA patients. We retrospectively analyzed the records of 47 RS3PE patients (28 men, 19 women, age 78.4 ± 7.5 years) and 46 EORA patients (10 men, 36 women; 77.0 ± 6.8 yrs) to compare the complications over a 1-year follow-up. The RS3PE and EORA groups' average initial PSL doses were 16.5 ± 7.2 mg/day and 7.3 ± 4.6 mg/day, respectively. During the 1-year follow-up after treatment, there was no significant increase in CVDs in both groups. However, infections occurred in nine RS3PE patients, which is a significantly higher incidence compared to the EORA patients with infections (n = 3). The initial PSL dose was the independent variable associated with the incidence of infection. Infections were significantly increased during elderly RS3PE patients' steroid therapy. The initial corticosteroid dose was an infection-risk factor.Key messagesInfections are increased during steroid therapy in elderly patients with RS3PE syndrome.The initial dose of corticosteroids was one of the risk factors for infections.

Validation of spectrophotometric method to quantify cabotegravir in simulated vaginal fluid and porcine vaginal tissue in ex vivo permeation and retention studies from thermosensitive and mucoadhesive gels

Cabotegravir (CAB) is an antiretroviral therapy (ARV) used for Human Immunodeficiency Virus (HIV) treatment. CAB has low solubility, which affects its bioavailability in oral therapy. Moreover, the injection form of CAB has difficulty in the administration process. Therefore, it is essential to develop a new drug delivery system for CAB. Vaginal drug delivery system offers many advantages such as a large surface area, increased drug bioavailability, and improved drug delivery. CAB was developed in thermosensitive and mucoadhesive vaginal gel preparations that provided optimal distribution in the vaginal mucosa. To support the process of formulation development, in this study, UV-visible spectrophotometry method was validated in methanol, simulated vaginal fluid (SVF) and vaginal tissue to quantify the amount of CAB in the gel preparations, in vitro, and ex vivo studies, respectively. The developed analytical method was subsequently validated according to ICH guidelines. The calibration curves in these matrices were found to be linear with correlation coefficient values (R²) ≥ 0.998. The LLOQ values in methanol, SVF and vaginal tissue were 2.15 µg/mL, 2.22 µg/mL, and 5.13 µg/mL, respectively. The developed method was found to be accurate and precise without being affected by dilution integrity. These methods were successfully applied to quantify the amount of CAB in gel preparations, in vitro, and ex vivo studies, showing uniformity of drug content and controlled release manner in the permeation profile for 24 h for both thermosensitive and mucoadhesive vaginal gels. Further analytical method is required to be developed for the quantification of CAB in in vivo studies.

Synergistic Interaction of Piperine and Thymol on Attenuation of the Biofilm Formation, Hyphal Morphogenesis and Phenotypic Switching in Candida albicans

The incidence of fungal infections has significantly increased in recent years due to the emergence of antifungal resistance. Biofilm formation is considered to be a major contributor to both the infectious diseases and to antimicrobial resistance. Consequently, biofilm-associated infections are often problematic to treat with existing therapeutics. Adhesion of C. albicans to the host surface or implanted materials followed by hyphal invasion and biofilm formation enhances C. albicans pathogenicity and virulence. Thus, developing a therapeutic agent that inhibits candidal adherence, biofilm development and morphological switching could improve clinical management of infections. The present investigation studied two emerging and alternatives strategies, namely antibiofilm and combinatorial approach, to attenuate biofilm formation and the expression of Candida virulence factors. Piperine and thymol are major bioactive components of pepper and thyme, respectively. These phytochemicals are known to possess numerous biological activities, including recently reported antibiofilm effects against C. albicans. The minimum biofilm inhibitory concentration (MBIC) of both phytochemicals was determined to be 32 µg/ml. The phytochemical treatment of Candida biofilms using piperine and thymol revealed synergistic effects at four different combinations of concentrations, i.e. 8 and 8, 8 and 4, 8 and 2 and 4 and 8 µg/ml. These synergistic combinations resulted in the significant reduction in adherence of Candida, hyphal extension and morphological transformation. Moreover, limited exposure of synergistic combinations controlled the hyphal elongation. Results were validated through the gene expression analysis. Results from the present investigation suggest that piperine and thymol can be synergistically employed for the treatment of biofilm-associated C. albicans infection.

Prevalence of Candida among denture wearers and nondenture wearers

Introduction:

A denture wearer is highly prone to develop Candida-associated denture stomatitis (CADS) due to the conversion of the normal oral commensal Candida spp. into a pathogen under favorable conditions. Immuno-compromised status, trauma from the prosthesis, other systemic conditions, and improper maintenance of the dentures by the patient are few of the causative agents which turn the oral balance into an unhealthy and unsuitable foundation for the wearing of the prosthesis.

Objective:

The objective of this study was to compare subjects wearing complete dentures and nondenture wearers regarding Candida isolates associated with disease and colonization among the different age groups.

Methodology:

A cross-sectional study was conducted among 60 subjects, 30 wearing complete dentures (Group-A) and 30 nondentures wearers (Group-B), were matched for gender, race, and age. The unstimulated saliva sample was collected and cultured in CHROMagar using standard protocols.

Results:

The mean value of the candidal colony-forming units with respect to Group A is Candida Albicans 0.36 ± 2.008, Candida krusei 0.27 ± 1.061, P value Group B: C. albicans 0.73 ± 2.196, C. krusei 0.36 ± 1.084. There was a significant relation between denture wearers and heavy growth of C. albicans and C. krusei in saliva culture with a P value of P-0.054 and P-0.036, respectively.

Conclusions:

These results indicate that denture wearers with oral Candida had a higher prevalence of CADS. Patients with removable prostheses should be informed about the importance of proper prosthesis and personal hygiene since dentures and age-related immunosuppression are both well-known risk factors associated with candidiasis development, the presence of yeast, even in healthy denture wearers, should be considered a risk factor for denture stomatitis that increases with the duration of denture use.

Root Causes of Fungal Coinfections in COVID-19 Infected Patients

COVID-19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has infected over 200 million people, causing over 4 million deaths. COVID-19 infection has been shown to lead to hypoxia, immunosuppression, host iron depletion, hyperglycemia secondary to diabetes mellitus, as well as prolonged hospitalizations. These clinical manifestations provide favorable conditions for opportunistic fungal pathogens to infect hosts with COVID-19. Interventions such as treatment with corticosteroids and mechanical ventilation may further predispose COVID-19 patients to acquiring fungal coinfections. Our literature review found that fungal coinfections in COVID-19 infected patients were most commonly caused by Aspergillus, Candida species, Cryptococcus neoformans, and fungi of the Mucorales order. The distribution of these infections, particularly Mucormycosis, was found to be markedly skewed towards low- and middle-income countries. The purpose of this review is to identify possible explanations for the increase in fungal coinfections seen in COVID-19 infected patients so that physicians and healthcare providers can be conscious of factors that may predispose these patients to fungal coinfections in order to provide more favorable patient outcomes. After identifying risk factors for coinfections, measures should be taken to minimize the dosage and duration of drugs such as corticosteroids, immunosuppressants, and antibiotics.

Current scenario of the search for new antifungal agents to treat Candida auris infections: An integrative review

Candida auris emerges as an important causative agent of fungal infections, with worrisome mortality rates, mainly in immunocompromised individuals. This scenario is worsened by the limited availability of antifungal drugs and the increasing development of resistance to them. Due to the relevance of C. auris infections to public health, several studies aimed to discover new antifungal compounds capable of overcoming this fungus. Nonetheless, these information are decentralized, precluding the understandment of the current status of the search for new anti-C. auris compounds. Thus, this integrative review aimed to summarize information regarding anti-C. auris compounds reported in literature. After using predefined selection criteria, 71 articles were included in this review, and data from a total of 101 substances were extracted. Most of the studies tested synthetic substances, including several azoles. Moreover, drug repurposing emerges as a suitable strategy to discover new anti-C. auris agents. Few studies, however, assessed the mechanism of action and the in vivo antifungal activity of the compounds. Therefore, more studies must be performed to evaluate the usefulness of these substances as anti-C. auris therapies.

Development of thermosensitive and mucoadhesive gels of cabotegravir for enhanced permeation and retention profiles in vaginal tissue: A proof of concept study

As an effective anti-HIV drug, cabotegravir (CAB) is currently administered via oral and injection routes, leading to several drawbacks, such as poor oral bioavailability and problems in the injection application process, as well as low drug concentration in vaginal tissue of woman patients. To overcome these issues, for the first time, we formulated CAB into three types of vaginal gels, considering the benefits of vaginal tissue as a delivery route. Thermosensitive gel, mucoadhesive gel, and the combination of these gels were developed as suitable carriers for CAB. Pluronics®, hydroxy propyl methyl cellulose (HPMC), Carbomer and poly(ethylene glycol) (PEG) 400 were used as thermosensitive, mucoadhesive and permeation enhancer agents, respectively. The gels were evaluated for their thermosensitive and mucoadhesive properties, as well as their pH values, viscosities, gel erosions, drug content recovery, in vitro drug release, ex vivo permeation, ex vivo retention, hemolytic activities, Lactobacillus inhibition activities and in vivo irritation properties. The results showed that all formulations showed desired characteristics for vaginal administration. Importantly, all formulations did not show hemolytic activities and inhibitions to Lactobacillus as normal bacteria in the vagina. Furthermore, no irritation in the vaginal tissues of the rats was observed by histopathological studies. Considering the thermosensitive and mucoadhesive properties, the combination of Pluronic® F127, Pluronic F68, and HPMC in thermosensitive-mucoadhesive vaginal gels was selected as the optimum dosage form for CAB as this formulation was able to provide ease administration due to its liquid form at room temperature. The use of PEG in this formulation was able to increase the penetrability of CAB through vaginal tissue with 0.61 ± 0.05 mg and 17.28 ± 0.95 mg of CAB being able to penetrate and localize in the vagina, respectively. Essentially, the optimum formulation was retained in the vaginal mucosa for>8 h. To conclude, further extensive in vivo studies should now be conducted to evaluate the efficacy of this approach.

Successful treatment of chronic hyperplastic candidiasis with 5-aminolevulinic acid photodynamic therapy: A case report

Chronic hyperplastic candidiasis (CHC) is a chronic oral mucosal infection caused by Candida. Refractory hyperplastic lesions may lead to epithelial dysplasia and carcinogenesis. Traditional surgical resection may cause irreversible damage and effect the patient's quality of life. This paper reports the case of a 63-year-old man with CHC. After routine treatment, local hyperplastic lesions remained. Photodynamic therapy with ALA was applied to the hyperplastic lesions and yielded satisfactory results, with no recurrence at 1 year. This case report describes a promising, effective method for the treatment of CHC.

Antibiofilm Efficacy of Luteolin Against Single and Dual Species of Candida albicans and Enterococcus faecalis

Candida albicans and Enterococcus faecalis biofilm-associated infections have been a huge challenge to the medical community. However, the efficacy of natural products against mixed biofilms of C. albicans and E. faecalis still remains largely unexploited. The aim of this study was to evaluate the efficacy of luteolin against planktonic cell growth, adhesion, and biofilm formation of C. albicans and E. faecalis in single and mixed cultures in vitro. The results showed that the minimum inhibitory concentrations of luteolin against planktonic cells of C. albicans, E. faecalis, and mixed cultures were 32 and 64 μg ml^–1, respectively. The results displayed that a remarkable variation in biofilm biomass, viability, structure, and composition of single and dual-species biofilms formed by mono- and dual-species biofilms of C. albicans and E. faecalis in the presence of luteolin was confirmed by mainly crystal violet staining assay (CVSA), optical microscope, field emission scanning electron microscope (FESEM), and confocal laser scanning microscope (CLSM). The tolerance of luteolin-treated single- and dual-species biofilms to antibiotics was found to obviously decrease, and the loss of biofilm matrix components (mainly polysaccharides and proteins) was revealed by CLSM. Moreover, luteolin was effective at inactivating biofilm cells, as well as destructing preformed biofilm structures by single and dual species by CVSA, FESEM, and CLSM. Collectively, these data indicate the potential of luteolin as a promising antibiofilm agent for the therapeutic management of biofilm-related infections induced by single and dual species of C. albicans and E. faecalis.

Factor associated with oral candidiasis caused by co-infection of Candida albicans and Candida glabrata: A retrospective study

This study aimed to determine the factors associated with the co-infection of Candida albicans and Candida glabrata. This retrospective study conducted between January 2015 and 2020 comprised 131 patients who were diagnosed with oral candidiasis. The factors associated with this condition were analyzed by univariate and multivariate logistic regression. Age and denture use were identified as significant risk factors in the univariate analysis. The multivariate logistic regression analysis revealed that denture use (odds ratio [OR], 8.44 95% confidence interval [CI], 1.99–28.3) and immunosuppressive therapy (OR, 9.20; 95% CI, 1.19–62.0) had significant effects on co-infection with the two Candida species. These findings suggest that immunosuppressive therapy using and dentures is significantly associated with oral candidiasis caused by co-infection of C. albicans and C. glabrata.

The genotypes and virulence attributes of C. albicans isolates from oral leukoplakia

Background

There is a debate as to whether some types of oral leucoplakias (OL) are caused by Candida species, and whether they contribute to the malignant transformation, associated with a minority of such lesions. As no detailed population analysis of yeast isolates from OL is available, we evaluated the virulence attributes, and genotypes of 35 C. albicans from OL, and compared their genotypes with 18 oral isolates from healthy individuals.

Material and Methods

The virulence traits evaluated were esterase, phospholipase, proteinase, haemolysin and coagulase production, and phenotypic switching activity, and yeast adherence and biofilm formation. DNA from OL and control yeasts were evaluated for A, B or C genotype status.

Results

Phospholipase, proteinase, and coagulase activity and biofilm formation was observed in 80%, 66%, 97 % and 77 % of the isolates, respectively. Phenotypic switching was detected in 8.6%, while heamolytic, and esterase activity and adherence were noted in all isolates.

Conclusions

The genotype A was predominant amongst both the OL and control groups. Due to the small sample size of our study a larger investigation to define the role of candidal virulent attributes in the pathogenicity of OL is warranted, and the current data should serve as a basis until then.

Key words:C. albicans, oral cavity, leukoplakia, virulence factors, genotyping.

Oral Candidal Load and Oral Health Status in Chronic Obstructive Pulmonary Disease (COPD) Patients: A Case-Cohort Study

Objective

The objective of this study was to determine the candidal load of the patients with Chronic Obstructive Pulmonary Disease (COPD) and evaluate the oral health status of subjects with COPD. Material and Methods. N = 112 COPD subjects and N = 100 control subjects were included in the study. The selection of COPD cases was confirmed based on the set criteria from the American College of Physicians. The oral health status was assessed as per WHO criteria to determine the score of decayed, missing, and filled teeth (DMFT), significant caries index (SiC), community periodontal index and treatment needs (CPITN), and oral hygiene index-simplified (OHI-S). Gram staining was performed to identify Candida using the whole saliva. Quantitative evaluation of the candidal load was carried out using Sabouraud Dextrose Agar (SDA). Chrome agar was used to differentiate between the commensal carriages. A statistical analysis paired t-test and 95% confidence interval (CI) for proportions was carried out using STATA software.

Results

Candidal growth was found in 21.42% (n = 24) of COPD cases and 1.1% (n = 11) of control cases (p < 0.05) (95% CI 0.45, 0.59). The DMFT score was 8.26 in COPD subjects and 4.6 in controls, the SiC score was 16.42 in COPD subjects and 10.25 in controls, and the CPITN score for both COPD and control cases was score 2.

Conclusion

In conclusion, there was a higher candidal load among subjects suffering from COPD. Theophylline medication can be a risk factor for increased candidal load in COPD patients.

Mycotic infections - mucormycosis and oral candidiasis associated with Covid-19: a significant and challenging association

Introduction

Bacterial and fungal secondary infections following COVID-19 disease are widely being reported and are an area that should receive careful attention. Mucormycosis is a fatal fungal condition affecting immunocompromised patients caused by a group of mold mucoromycetes. Candida albicans (C. albicans) is an oral commensal present in almost 40–65% of healthy oral cavities in adults. Several cases of mucormycosis and oral candidiasis have been reported lately in COVID-19 patients, and it may elevate the associated risks of morbidity and mortality.

Materials and Methods

Articles were taken from a period of 2020 to April 2021 using search sources such as Cochrane, PubMed, Fungiscope and Mycobank using keywords mucormycosis, Black fungus, oral candidiasis, white fungus, COVID-19, Sars-Cov-2.

Discussion

The development of oral mucocutaneous lesions, such as mucormycosis and candidiasis in COVID-19 patients could be due to inhaling spores resulting in pulmonary and/or sinus congestion and prolonged mechanical ventilation in the ICU settings and the long-term use of broad-spectrum antibiotics respectively. The onset of candidiasis after the emergence of COVID-19 clinical signs and symptoms varied considerably and is reported within 1–30 days in most of the cases reported in the literature. Biofilms present on the denture surfaces are predisposing factors to oral candidiasis. We aim to summarize the limited data available regarding diagnosis, clinical presentation, and therapeutic approaches for the management of Mucormycosis and oral candidiasis in COVID-19 patients.

Conclusion

Careful monitoring of oral lesions should be instituted through interdisciplinary telemedicine and teleconsultation to aid in primary diagnosis, thereby avoiding personal attendance during the pandemic. Dental practitioners should be included among the interdisciplinary teams for exhaustive intraoral examination and reduce the risk of morbidity and mortality.

Isolation and identification of oral Candida species in potentially malignant disorder and oral squamous cell carcinoma

CONTEXT

Oral cancer is one of the ten most common cancers in the world. More than 95% of the carcinomas of the oral cavity are of squamous cell type in nature. Oral Candida is a "yeast-like opportunistic pathogen." The Candida genus is comprised of over 150 species of asporogenous "yeast-like" fungi.

AIM AND OBJECTIVES

The aim of study is to correlate the association of oral fungal infection in progression of oral squamous cell carcinoma (OSCC) and potentially malignant disorders. The current study was undertaken to probe the isolation and identification of oral Candida species in potentially malignant disorder and OSCC versus normal oral mucosa.

MATERIALS AND METHODS

Twenty patients for each abovementioned three lesions were randomly selected by using swabs. These swabs were subsequently inoculated in agar medium. Candida grows as white, convex colonies. Samples growing 1-3 colony-forming units (CFUs) were considered normal flora of the oral cavity. The specimens showing moderate to heavy growth were subjected to tests for identification of species of Candida. The chromogenic medium, HiMedia CHROMagar, has chromogenic substances which helps in the quick detection of Candida species, based on the reactions between the extract enzymes of the dissimilar species and the chromogenic substances.

STATISTICAL ANALYSIS

Chi-square test, one-way analysis of variance test, and post hoc Tukey's test were utilized.

RESULTS

According to our study, Candida albicans, Candida krusei, Candida tropicalis, and Candida parapsilosis in the culture were found to be in increasing incidence from healthy, OSCC, and oral potentially malignant disorders (OPMDs). These results clearly indicated that Candida species are increasing in the CFUs (P < 0.0001).

CONCLUSION

Our study showed a higher intensity of Candida in OPMD and squamous cell carcinoma patients with results. The increasing CFU level and hyphae of Candida species in individual biopsy tissue with oral potentially malignant lesions to OSCC suggest that this pathogen plays a role in disease development and could aid in identifying the pathogenic commensal.

Oral Candidal Colonization in Patients with Different Prosthetic Appliances

Oral infections caused by Candida species are becoming more common, which may be related to an increase in the number of immunologically compromised patients as well as favorable conditions in the oral cavity that often include removable prosthetic appliances. The purpose of this study was to determine the presence of a particular Candida species in patients with PMMA and Cr-Co prosthetic appliances, as well as the salivary flow rate, and oral signs and symptoms. This investigation included a total of 120 subjects with different kinds of removable dentures. A sample of concentrated oral rinse was collected from all subjects in order to detect Candida colonization and identify the Candida species, a quantum of salivation was measured, and subjects were examined clinically. Candida spp. was predominant among the subjects who were denture wearers (p < 0.0001). In all subjects, the most frequently detected species was C.albicans. A statistically significant difference was found between the prevalence of C.albicans (p < 0.001) and C.krusei (p < 0.001) in denture wearers. Subjects with PMMA-based removable prosthetic appliances mostly demonstrated a significant decrease in salivation (p < 0.001), an increase in burning sensations (p < 0.001), and dry mouth (p < 0.001) compared to the subjects who wore partial dentures with Co–Cr metallic frameworks. Red oral lesions were more frequently found among the subjects with partial dentures with Co–Cr metallic frameworks (p < 0.001). Regardless of the material used for the denture, patients must be regularly checked by their dentists in order to prevent the development of oral lesions.

Streptococcus salivarius K12 inhibits Candida albicans aggregation, biofilm formation and dimorphism

Candida albicans causes candidiasis, particularly in immunocompromised patients. Streptococcus salivarius K12 (K12) is a probiotic isolated from a healthy oral cavity. The study aimed to determine the effect of K12 on C. albicans aggregation, biofilm formation and dimorphism. C. albicans ATCC MYA-4901, acquired immunodeficiency syndrome (AIDS) isolate (ALC2), and oral cancer isolate (ALC3) and K12 were used in the study. All C. albicans strains and K12 were grown in yeast peptone dextrose agar and brain heart infusion agar, respectively, prior to aggregation, biofilm and dimorphism assays. Auto-aggregation of C. albicans MYA-4901 and ALC2 was categorised as high, while the co-aggregation of the strains was low in the presence of K12. C. albicans total cell count decreased significantly when co-cultured with K12 compared with monocultured C. albicans biofilm (p < 0.05). Inhibition of yeast-to-hyphae transition was also observed when co-cultured with K12. In conclusion, K12 inhibits C. albicans aggregation, biofilm formation and dimorphism.

Oral Candidosis: Pathophysiology and Best Practice for Diagnosis, Classification, and Successful Management

Oral candidosis is the most common fungal infection that frequently occurs in patients debilitated by other diseases or conditions. No candidosis happens without a cause; hence oral candidosis has been branded as a disease of the diseased. Prior research has identified oral candidosis as a mark of systemic diseases, such as hematinic deficiency, diabetes mellitus, leukopenia, HIV/AIDS, malignancies, and carbohydrate-rich diet, drugs, or immunosuppressive conditions. An array of interaction between Candida and the host is dynamic and complex. Candida exhibits multifaceted strategies for growth, proliferation, evasion of host defenses, and survival within the host to induce fungal infection. Oral candidosis presents a variety of clinical forms, including pseudomembranous candidosis, erythematous candidosis, angular cheilitis, median rhomboid glossitis, cheilocandidosis, juxtavermillion candidosis, mucocutaneous candidosis, hyperplastic candidosis, oropharyngeal candidosis, and rare suppurative candidosis. The prognosis is usually favorable, but treatment failure or recurrence is common due to either incorrect diagnosis, missing other pathology, inability to address underlying risk factors, or inaccurate prescription of antifungal agents. In immunocompromised patients, oropharyngeal candidosis can spread to the bloodstream or upper gastrointestinal tract, leading to potentially lethal systemic candidosis. This review therefore describes oral candidosis with regard to its pathophysiology and best practice for diagnosis, practical classification, and successful management.

Evaluation of Effectiveness of a Toothpaste Containing Tea Tree Oil and Ethanolic Extract of Propolis on the Improvement of Oral Health in Patients Using Removable Partial Dentures

The aim of this study was to evaluate the effect of toothpaste containing natural tea tree essential oil (TTO) and ethanolic extract of propolis (EEP), on microflora and selected indicators of oral health in patients using removable acrylic partial dentures. Fifty patients with varying conditions of hygiene were divided into two groups. The study group received the toothpaste with TTO and EEP, while the control group received the same toothpaste but without TTO and EEP. At the first visit, oral hygiene and hygiene of the prostheses were carried out. Control visits took place 7 and 28 days later and compared to baseline. Indexes like API (Approximal Plaque Index), mSBI (modified Sulcus Bleeding Index), OHI-s (simplified Oral Hygiene Index), and DPI (Denture Plaque Index) were assessed in three subsequent stages, and swabs were collected from floor of the mouth area to assess the microbiota. After 7 and 28 days of using the toothpaste with TTO and EEP, a statistically significant decrease of the examined indicator values were observed in the study group as compared to the values upon the initial visit. The number of isolated strains of microorganisms in the study group was decreased or maintained at the same level, whereas in the control group an increase in the number of isolated strains was observed. The observed stabilization of oral microbiota in patients from the study group confirms the beneficial activity of toothpaste containing EEP and TTO compared to the control group.

Nystatin effect on chlorhexidine efficacy against Streptococcus mutans as planktonic cells and mixed biofilm with Candida albicans

Objective

The aim of this study was to evaluate the effect of nystatin on the efficacy of chlorhexidine against Streptococcus mutans in planktonic cells and mixed biofilm with Candida albicans.

Material and methods

S. mutans ATCC 25,175 in suspension and also combined with C. albicans ATCC 18,804 in biofilm were cultured. Minimum inhibitory concentration (MIC), crystal violet colorimetric assay, and colony-forming unit counting (CFUs/mL) were performed.

Results

An increased MIC of chlorhexidine against S. mutans was observed when the drugs were administered mixed in a single formulation and with time intervals in between, except for the 30-min interval. The biofilm optical density (OD) in treatments using chlorhexidine and nystatin combined did not significantly differ from chlorhexidine alone. Either in biofilm colorimetric assay or determination of CFUs, the combined treatments with nystatin administered before chlorhexidine had less effect on chlorhexidine efficacy.

Conclusions

Nystatin interferes with the action of chlorhexidine against S. mutans. The antimicrobial effectiveness of the combined drugs depends on their concentration, time interval used, and the planktonic or biofilm behavior of the microorganisms.

Clinical relevance

In view of the great number of patients that can receive a prescription of chlorhexidine and nystatin concomitantly, this study contributes to the knowledge about the effect of the combined drugs. Given the high prevalence of prescriptions of chlorhexidine and nystatin in dentistry, dental professionals should be aware of their possible antagonistic effect.

The Interactions Between Candida albicans and Mucosal Immunity

Mucosa protects the body against external pathogen invasion. However, pathogen colonies on the mucosa can invade the mucosa when the immunosurveillance is compromised, causing mucosal infection and subsequent diseases. Therefore, it is necessary to timely and effectively monitor and control pathogenic microorganisms through mucosal immunity. Candida albicans is the most prevalent fungi on the mucosa. The C. albicans colonies proliferate and increase their virulence, causing severe infectious diseases and even death, especially in immunocompromised patients. The normal host mucosal immune defense inhibits pathogenic C. albicans through stepwise processes, such as pathogen recognition, cytokine production, and immune cell phagocytosis. Herein, the current advances in the interactions between C. albicans and host mucosal immune defenses have been summarized to improve understanding on the immune mechanisms against fungal infections.

Yeast-Host Interactions: Anadenanthera colubrina Modulates Virulence Factors of C. albicans and Inflammatory Response In Vitro

Oral candidiasis is one of the most common fungal infections in humans. Its incidence has increased widely, as well as the antifungal resistance, demanding for the search for novel antifungal therapeutic agents. Anadenanthera colubrina (Vell.) Brenan is a plant species that has been proven to possess pharmacological effects, including antifungal and anti-inflammatory activities. This study evaluated in vitro the effects of standardized A. colubrina extract on virulence factors of Candida albicans and its regulation on immune response through C. albicans-host interaction. Antifungal activity was evaluated by Broth Microdilution Method against reference Candida strains (C. albicans, C. glabrata, C. tropicalis; C. dubliniensis). Anti-biofilm effect was performed on C. albicans mature biofilm and quantified by CFU/mL/g of biofilm dry weight. Proleotlytic enzymatic activities of proteinase and phospholipase were assessed by Azocasein and Phosphatidylcholine assays, respectively. Cytotoxicity effect was determined by Cell Titer Blue Viability Assay on Human Gingival Fibroblasts. Co-cultured model was used to analyze C. albicans coexisting with HGF by Scanning Electron Microscopy and fluorescence microscopies; gene expression was assessed by RT-PCR of C. albicans enzymes (SAP-1, PLB-1) and of host inflammatory cytokines (IL-6, IL-8, IL-1β, IL-10). Cytokines secretion was analysed by Luminex. The extract presented antifungal effect with MIC<15.62 μg/ml against Candida strains. Biofilm and proteolytic activity were significant reduced at 312.4 μg/ml (20 × 15.62 μg/ml) extract concentration. Cell viability was maintained higher than 70% in concentrations up to 250 μg/ml (LD50 = 423.3 μg/ml). Co-culture microscopies demonstrated a substantial decreased in C. albicans growth and minimal toxicity against host cells. Gene expressions of SAP-1/PLB-1 were significantly down-regulated and host immune response was modulated by a significant decreased on IL-6 and IL-8 cytokines secretion. A. colubrina had antifungal activity on Candida strains, antibiofilm, and anti-proteolytic enzyme effects against C. albicans. Presented low cytotoxicity to the host cells and modulatory effects on the host immune response.

Biomaterials for the Prevention of Oral Candidiasis Development

Thousands of microorganisms coexist within the human microbiota. However, certain conditions can predispose the organism to the overgrowth of specific pathogens that further lead to opportunistic infections. One of the most common such imbalances in the normal oral flora is the excessive growth of Candida spp., which produces oral candidiasis. In immunocompromised individuals, this fungal infection can reach the systemic level and become life-threatening. Hence, prompt and efficient treatment must be administered. Traditional antifungal agents, such as polyenes, azoles, and echinocandins, may often result in severe adverse effects, regardless of the administration form. Therefore, novel treatments have to be developed and implemented in clinical practice. In this regard, the present paper focuses on the newest therapeutic options against oral Candida infections, reviewing compounds and biomaterials with inherent antifungal properties, improved materials for dental prostheses and denture adhesives, drug delivery systems, and combined approaches towards developing the optimum treatment.

Lactate Like Fluconazole Reduces Ergosterol Content in the Plasma Membrane and Synergistically Kills Candida albicans

Candida albicans is an opportunistic pathogen that induces vulvovaginal candidiasis (VVC), among other diseases. In the vaginal environment, the source of carbon for C. albicans can be either lactic acid or its dissociated form, lactate. It has been shown that lactate, similar to the popular antifungal drug fluconazole (FLC), reduces the expression of the ERG11 gene and hence the amount of ergosterol in the plasma membrane. The Cdr1 transporter that effluxes xenobiotics from C. albicans cells, including FLC, is delocalized from the plasma membrane to a vacuole under the influence of lactate. Despite the overexpression of the CDR1 gene and the increased activity of Cdr1p, C. albicans is fourfold more sensitive to FLC in the presence of lactate than when glucose is the source of carbon. We propose synergistic effects of lactate and FLC in that they block Cdr1 activity by delocalization due to changes in the ergosterol content of the plasma membrane.

Antimicrobial photodynamic therapy for oral Candida infection in adult AIDS patients: A pilot clinical trial

BACKGROUND

Antimicrobial photodynamic therapy (aPDT) using methylene blue (MB) plus potassium iodide (KI) has been shown to be effective in killing Candida albicans in many in vitro and in vivo studies, however, there are limited reports of clinical investigations. This study aimed to explore the clinical application of aPDT with MB plus KI for the treatment of oral infection caused by C. albicans in adult acquired immune deficiency syndrome (AIDS) patients.

METHODS

A total of 21 adult AIDS patients with C. albicans oral candidiasis were divided into two groups according to MB concentration and received two consecutive aPDT treatments. Immediately before and after the aPDT treatments, C. albicans yeast isolates were recovered to measure the colony-forming units per mL (CFU/mL), biofilm formation, and to analyze the 25S rDNA genotype. Patients were assessed for the clinical recovery of oral lesions and improvement of symptoms.

RESULTS

The Log₁₀ CFU/mL of C. albicans decreased significantly after the second aPDT but not the first aPDT. There was no significant difference between the two MB concentrations. Both aPDT protocols decreased the oral lesions and clinical symptoms with no significant difference after 2-fraction aPDT. The biofilm formation of C. albicans isolates did not change before and after aPDT. The killing efficiency of 2-fraction-aPDT was not associated with either biofilm formation or 25S rDNA genotype.

CONCLUSIONS

Two-fraction-aPDT with MB plus KI could reduce the number of viable C. albicans fungal cells and improve the clinical symptoms of oral candidiasis in adult AIDS patients, regardless of the biofilm formation or 25S rDNA genotype of infected C. albicans isolates.

Cation Transporters of Candida albicans-New Targets to Fight Candidiasis?

Candidiasis is the wide-spread fungal infection caused by numerous strains of yeast, with the prevalence of Candida albicans. The current treatment of candidiasis is becoming rather ineffective and costly owing to the emergence of resistant strains; hence, the exploration of new possible drug targets is necessary. The most promising route is the development of novel antibiotics targeting this pathogen. In this review, we summarize such candidates found in C. albicans and those involved in the transport of (metal) cations, as the latter are essential for numerous processes within the cell; hence, disruption of their fluxes can be fatal for C. albicans.

Fungal Infections of Oral Cavity: Diagnosis, Management, and Association with COVID-19

The frequency of fungal infections is increasing due to immunodeficiency viruses and immunosuppressive drugs. The most common fungal infection of the oral cavity is candidiasis. The existence of Candida can be a part of normal commensal; hence, the isolation of Candida in the absence of clinical symptoms should exclude candidiasis. The pathogenicity of Candida is witnessed as opportunistic when immune status is compromised. Oral fungal infections are uncommon, but when identified, these infections are associated with greater discomfort and are sometimes destruction of tissues. Cytology and tissue biopsy are helpful in confirming the clinical diagnosis. The management of oral fungal infections must strategically focus on signs, symptoms, and culture reports. This article reviews information on diagnosis and therapeutic management of aspergillosis, cryptococcosis, histoplasmosis, blastomycosis, mucormycosis, and geotrichosis.

Development of Self-Nanoemulsifying Drug Delivery Systems Containing 4-Allylpyrocatechol for Treatment of Oral Infections Caused by Candida albicans

Clinical use of 4-Allylpyrocatechol (APC), a potential antifungal agent from Piper betle, is limited because of its low water solubility. The current study explores the development of the self-nanoemulsifying drug delivery system (SNEDDS) containing APC (APC-SNEDDS) to enhance APC solubility. Results demonstrated that excipient type and concentration played an important role in the solubility of APC in the obtained SNEEDS. SNEDDS, comprising 20% Miglyol 812N, 30% Maisine 35-1, 40% Kolliphor RH40, and 10% absolute ethanol, provided the highest loading capacity and significantly increased water solubility of APC. Oil-in-water nanoemulsions (NE) with droplet sizes of less than 40 nm and a narrow size distribution were obtained after dispersing this APC-SNEDDS in water. The droplets had a negative zeta potential between -10 and -20 mV. The release kinetics of APC from APC-SNEDDS followed the Higuchi model. The NE containing 1.6 mg APC/mL had effective activity against Candida albicans with dose-dependent killing kinetics and was nontoxic to normal cells. The antifungal potential was similar to that of 1 mg nystatin/mL. These findings suggest that APC-SNEDDS are a useful system to enhance the apparent water solubility of APC and are a promising system for clinical treatment of oral infection caused by C. albicans.

New perspectives on the topical management of recurrent candidiasis

Candidiasis is a common opportunistic infection caused by fungi of the Candida genus that affects mainly mucocutaneous tissues (e.g., vaginal, oral, and mammary). This condition has been known for a long time; thus, innumerous topical and systemic treatments are already available on the market worldwide. Yet, recurrent superficial candidiasis (RSC) is an expected outcome, still lacking effective and convenient treatments. Although several individual conditions may contribute to disease recurrence, biofilms' presence seems to be the main etiological factor contributing to antifungal resistance. More than proposing novel antifungal agents, current research seems to be focusing on improving the pharmaceutical technology aspects of formulations to address such a challenge. These include extending and improving intimate contact of drug delivery systems with the mucocutaneous tissues, increasing drug loading dose, and enhancing topical drug permeation. This review discusses the current understanding of the RSC and the use of pharmaceutical technology tools in obtaining better results. Even though several drawbacks of conventional formulations have been circumvented with the help of nano- or microencapsulation techniques and with the use of mucoadhesive formulation excipients, many challenges remain. In particular, the need to mask the unpalatable taste of formulations for the treatment of oral candidiasis, and the necessity of formulations with a "dryer" sensorial feeling and improved performances in providing higher bioavailability for the treatment of mammary and vaginal candidiasis.