Oral fungal infections: an update for the general practitioner

Silver Nanoparticle-Embedded Carbon Nitride: Antifungal Activity on Candida albicans and Toxicity toward Animal Cells

The development of engineered nanomaterials has been considered a promising strategy to control oral infections. In this study, silver-embedded carbon nitrides (Ag@g-CN) were synthesized and tested against Candida albicans, investigating their antifungal action and biocompatibility in animal cells. Ag@g-CN was synthesized by a simple one-pot thermal polymerization technique and characterized by various analytical techniques. X-ray diffraction (XRD) analysis revealed slight alterations in the crystal structure of g-CN upon the incorporation of Ag. Fourier transform infrared (FT-IR) spectroscopy confirmed the presence of Ag-N bonds, indicating successful silver incorporation and potential interactions with g-CN's amino groups. UV-vis spectroscopy demonstrated a red shift in the absorption edge of Ag@g-CN compared with g-CN, attributed to the surface plasmon resonance effect of silver nanoparticles. Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) confirmed the 2D layered sheet like morphology of both materials. The Ag 3d peaks found in X-ray photoelectron spectroscopy (XPS) confirmed the presence of metallic Ag0 nanoparticles in Ag@g-CN. The Ag@g-CN materials exhibited high antifungal activity against reference and oral clinical strains of C. albicans, with minimal inhibitory concentration (MIC) ranges between 16-256 μg/mL. The mechanism of Ag@g-CN on C. albicans was attributed to the disruption of the membrane integrity and disturbance of the biofilm. In addition, the Ag@g-CN material showed good biocompatibility in the fibroblastic cell line and in Galleria mellonella, with no apparent cytotoxicity observed at a concentration up to 1000 μg/mL. These findings demonstrate the potential of the Ag@g-CN material as an effective and safe antifungal agent for the treatment of oral fungal infections.

Lactoferrin as a potential therapeutic for the treatment of Candida-associated denture stomatitis

BACKGROUND

The use of prostheses in the oral cavity creates favorable conditions for Candida colonization, which may subsequently lead to Candida-associated denture stomatitis (CADS). Due to its many contributing factors and frequent relapses, CADS is difficult to manage. Given the rise in drug resistance among fungal species, it is critical to develop new therapeutic approaches, reduce the required dosage of medications, and minimize the toxicity and side effects of therapy.

HIGHLIGHT

Salivary lactoferrin, a multifunctional glycoprotein, is thought to be the first line of defense against microbial invasion of mucosal surfaces.

CONCLUSION

Current research emphasizes the capability of lactoferrin and its derivatives to eliminate a broad spectrum of Candida species. It may be an appealing option for use in monotherapy or in combination with common medications for oral stomatitis treatment. This review provides an overview of the current understanding of lactoferrin's anti-fungal effects in oral candidiasis.

Dry Mouth Dilemma: A Comprehensive Review of Xerostomia in Complete Denture Wearers

Xerostomia, commonly known as dry mouth, presents a significant challenge for individuals wearing complete dentures, affecting their oral health and quality of life. This review explores the relationship between saliva and complete dentures, highlighting the varied management strategies for xerostomia. Saliva plays a critical role in denture retention, lubrication, and oral environment buffering. Complete denture wearers often experience reduced salivary flow, aggravating symptoms of xerostomia. Various management approaches are discussed, including general measures such as hydration and salivary stimulation techniques which aim to boost saliva production naturally. The use of salivary substitutes provides artificial lubrication and moisture to alleviate dry mouth discomfort. Oral lubricating devices, such as sprays, gels, and lozenges, offer relief by mimicking saliva's lubricating properties, thereby improving denture stability and comfort. This review addresses the etiology of xerostomia in complete denture wearers and explores preventive measures to reduce its impact. A comprehensive approach has been discussed for the management of xerostomia which will help to improve the oral health and well-being of complete denture wearers experiencing dry mouth.

Our current clinical understanding of Candida biofilms: where are we two decades on?

Clinically we have been aware of the concept of Candida biofilms for many decades, though perhaps without the formal designation. Just over 20 years ago the subject emerged on the back of progress made from the bacterial biofilms, and academic progress pace has continued to mirror the bacterial biofilm community, albeit at a decreased volume. It is apparent that Candida species have a considerable capacity to colonize surfaces and interfaces and form tenacious biofilm structures, either alone or in mixed species communities. From the oral cavity, to the respiratory and genitourinary tracts, wounds, or in and around a plethora of biomedical devices, the scope of these infections is vast. These are highly tolerant to antifungal therapies that has a measurable impact on clinical management. This review aims to provide a comprehensive overight of our current clinical understanding of where these biofilms cause infections, and we discuss existing and emerging antifungal therapies and strategies.

Oral mycotic infection caused by a rare Verticillium species - a case report

BACKGROUND

Deep-seated fungal infections of the oral cavity present a diagnostic challenge as the clinical presentation is usually aggressive leading to misdiagnosis of malignancy. Nevertheless, the species of fungi responsible for such diseases in immunocompromised individuals are varied thus, further complicating the diagnosis.

CASE PRESENTATION

Presented below is a case regarding the diagnosis and management of deep mycotic infection of the oral cavity caused by a fungus that very rarely causes disease in humans, the Verticillium species.

CONCLUSIONS

The case highlights the fact that rare pathogens should also be considered in the differential diagnosis, especially in patients with debilitating conditions like uncontrolled diabetes. Likewise, histopathological evaluation and microbiological investigations are of paramount importance and remain the gold standard to reach a definitive diagnosis.

Oral candidiasis in patients with kidney transplantation in Iran: prevalence and antifungal susceptibility pattern

Aim: This study aimed to identify Candida species recovered from the oral cavity of patients with kidney transplantation. Materials & methods: Two swabs were taken from the oral cavities of 40 patients before and after transplantation, cultured on Sabouraud dextrose agar, and yeasts identified. Antifungal drug susceptibility testing was performed with fluconazole and itraconazole. Results: Candida glabrata was the most frequently isolated species in patients, followed by Candida albicans and Rhodotorula. C. glabrata isolates from patients before transplantation were resistant to fluconazole, whereas C. albicans was fluconazole-resistant both before and after transplantation. Conclusion: The importance of non-albicans Candida species in the oral cavity of patients sheds light on performing antifungal tests for achieving the best outcome to prevent therapeutic failure.

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.

Impact of surface pre-reacted glass ionomer filler eluate on lipase gene expression in Candida albicans: An in vitro study

Although a surface pre-reacted glass ionomer (S-PRG) exerts a suppressive effect on Candida albicans (C. albicans) activity and growth, its influence on the expression of the lipase gene (LIP) family including LIP1-LIP10, an indicator of clinical infection, has not yet been investigated. Therefore, in this study, we evaluated the effect of S-PRG filler eluates on LIP expression in C. albicans using real-time reverse-transcription polymerase chain reaction. Candida albicans was treated with an S-PRG filler diluted at ratios of 1:32 and 1:64 for 24 h at 37°C. The diluted S-PRG filler eluates (1:32) suppressed lipase activity in C. albicans by downregulating LIP5 (0.54±0.25 relative to that of the control) and LIP8 (0.35±0.074) expression after 24 h, which corresponded with decreased lipase activity. At a dilution factor of 1:64, there was no significant difference in LIP expression. Thus, the S-PRG filler eluate has potential to suppress fungal activity by downregulating LIP expression.

The Promotional Effect of GW4869 on C. albicans Invasion and Cellular Damage in a Murine Model of Oral Candidiasis

Candida albicans (C. albicans) is one of the most common fungi in the human body; it is an opportunistic pathogen and can cause candidiasis. Extracellular vesicles (EVs) derived from the host cells have a potentially protective effect against pathogens and can be developed as vaccine formulations. GW4869 can inhibit the production and release of EVs. Previous studies have indicated that GW4869 can alter the immune and inflammatory responses of the host. However, the effect of GW4869 on Candida infection and the anti-Candida response of the host has not been investigated. We evaluated the effect of GW4869 on C. albicans invasion, biofilm formation, and cellular damage in a murine model of oral candidiasis. In this study, C. albicans-infected mice were injected with or without GW4869. The results proven by macroscopic, microscopic, and ultramicroscopic methods showed that GW4869 treatment exacerbated the oral candidiasis of mice, promoted C. albicans invasion and biofilm formation, and aggravated oral mucosal inflammation and cellular ultrastructural damage. The results are beneficial in the further exploration of the immune mechanism of C. albicans infection.

Oral Chronic Hyperplastic Candidiasis and Its Potential Risk of Malignant Transformation: A Systematic Review and Prevalence Meta-Analysis

Chronic hyperplastic candidiasis (CHC) is a prototypical oral lesion caused by chronic Candida infection. A major controversy surrounding CHC is whether this oral lesion owns malignant transformation (MT) potential. The aim of the present study was to evaluate current evidence on the MT of CHC and to determine the variables which have the greatest influence on cancer development. Bibliographical searches included PubMed, Embase, Web of Science, Scopus and LILACS. The cohort studies and case series used to investigate the MT of CHC were deemed suitable for inclusion. The quality of the enrolled studies was measured by the Joanna Briggs Institute scale. Moreover, we undertook subgroup analyses, assessed small study effects, and conducted sensitivity analyses. From 338 studies, nine were finally included for qualitative/quantitative analysis. The overall MT rate for CHC across all studies was 12.1% (95% confidential interval, 4.1–19.8%). Subgroup analysis showed that the MT rate increased when pooled analysis was restricted to poor quality studies. It remains complex to affirm whether CHC is an individual and oral, potentially malignant disorder according to the retrieved evidence. Prospective cohort studies to define the natural history of CHC and a consensus statement to clarify a proper set of diagnostic criteria are strongly needed. PROSPERO ID: CRD42022319572.

Biofilm and hyphal inhibitory synergistic effects of phytoactives piperine and cinnamaldehyde against Candida albicans

Oral candidiasis, the most common mycotic infection of the human oral cavity is non-life-threatening yet if untreated may advance as systemic infections. Ability of Candida albicans to adapt sessile lifestyle imparts resistance to drugs and host immunity. Consequently, due to limited effectiveness of conventional antifungal treatment, novel therapeutic strategies are required. In the present study, synergistic interaction of phytochemicals, piperine and cinnamaldehyde against the biofilm and hyphal of C. albicans was evaluated. Minimum inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) of piperine and cinnamaldehyde against C. albicans were analysed through microbroth dilution assay and crystal violet staining method, respectively. Combinatorial biofilm and hyphal inhibitory effect were investigated through checkerboard assay. In vitro results were validated through gene expression analysis. BIC of piperine and cinnamaldehyde was determined to be 32 µg/mL and 64 µg/mL, respectively. Interaction between these two phytocomponents was found to be synergistic and six different synergistic antibiofilm combinations were identified. Microscopic analysis of biofilm architecture also evidenced the biofilm and surface adherence inhibitory potential of piperine and cinnamaldehyde combinations. Phenotypic switching between yeast and hyphal morphological forms was influenced by synergistic combinations. qPCR analysis corroborated the results of in vitro activities. nrg1 and trp1, the negative transcriptional regulators of filamentous growth were upregulated whereas other genes that are involved in biofilm formation, filamentous growth, adhesion etc were found to be downregulated. These proficient phytochemical combinations provide a new therapeutic avenue for the treatment of biofilm associated oral candidiasis and to combat the recurrent infections due to antibiotic resistance.

The oral mycobiome: Oral epithelial dysplasia and oral squamous cell carcinoma

Fungi, a diverse group of eukaryotic organisms, play distinct roles in health and disease. Recent advances in the field of mycobiology have enabled the characterization of the "human mycobiome." The human mycobiome has extensively been studied in various disease models. However, to date, the role of the oral mycobiome in oral carcinogenesis has yet to be elucidated. Candida albicans, the most common oral colonizer, has been speculated to display tumorigenic effects; however, the literature lacks consistent documentation from mechanistic studies on whether oral mycobiota act as drivers, facilitators, or passive colonizers of oral premalignancy and cancer. This review article provides an overview of existing hypothesis-driven mechanistic models that outline the complex interplay between the oral mycobiome and oral epithelial dysplasia as well as their potential clinical implications.

A Practical Guide to the Management of Oral Candidiasis in Patients with Plaque Psoriasis Receiving Treatments That Target Interleukin-17

Plaque psoriasis is an immune-mediated inflammatory skin disease associated with the dysregulation of cytokines, especially those involved in the interleukin (IL)-23/IL-17 pathways. In recent years, there has been growing interest in developing biologic therapies that target these pathways. However, inhibition of the cytokines of the IL-23/IL-17 pathways may increase patients' risk of developing fungal infections, particularly oral candidiasis. Therefore, it is important that dermatology practitioners can effectively diagnose and treat oral candidiasis. In this review, we examine the role of the IL-23/IL-17 pathways in antifungal host defense, and provide a practical guide to the diagnosis and treatment of oral candidiasis in patients with psoriasis. Overall, while treatment with anti-IL-17 medications leads to an increased incidence of oral candidiasis in patients with psoriasis, these cases are typically mild or moderate in severity and can be managed with standard antifungal therapy without discontinuing treatment for psoriasis. If applicable, patients with psoriasis should also be advised to practice good oral hygiene and manage or control co-existing diabetes, and should be provided with information on smoking cessation to prevent oral candidiasis.

Pharmacological Management of Common Soft Tissue Lesions of the Oral Cavity

Soft tissue lesions commonly seen in the oral cavity tend to overlap in their onset, presentation, and location making it difficult to appreciate their etiology. In some instances, common oral soft tissue lesions can create confusion due to similar clinical appearance or unusual presentation; therefore, proper diagnosis of the lesion is key in pharmacologic management. In ulcerative conditions, topical steroids can decrease the symptoms and improve healing time, but do not affect the recurrence rate. Always be suspicious of soft tissue lesions that are nonresolving or recurrent lesions as they may warrant further investigation to rule out malignancy or associated systemic conditions. This article discusses key clinical presentations and the proper topical and systemic pharmacologic treatments.

Otorhinolaryngology Manifestations of Systemic Illness

Ear-nose-throat (ENT) manifestations are among the most frequently observed clinical features of systemic illnesses. The patients often present with overt findings of head and neck lesions such as salivary gland swelling or lymphadenopathy. In contrast, patients may present with covert findings of auditory, nasal, and laryngeal symptoms that are less obvious and are often overlooked. Therefore, clinicians should have a high index of suspicion to identify the underlying disease. Early recognition and prompt treatment or referral to specialists may prevent morbidity and mortality. This article discusses various systemic illnesses with ENT manifestations that are commonly encountered.

Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation

Aim

Bacterial and fungal infections are serious, life‐threatening conditions after kidney transplantation. The development of oral/oesophageal candidiasis after kidney transplantation is not a reported risk factor for subsequent severe infection. This study was performed to investigate the relationship between oral/oesophageal candidiasis after kidney transplantation and the development of subsequent infection requiring hospitalization.

Methods

This retrospective study included 522 consecutive patients who underwent kidney transplantation at Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital from 1 January 2010 to 1 February 2019. Ninety‐five percentage of patients were living donor transplant recipients. Visual examination was performed to detect oral candidiasis, beginning immediately after kidney transplantation; upper gastrointestinal endoscopy was performed 8–10 months after kidney transplantation. Twenty‐five patients developed candidiasis (Candida‐onset group) and 497 did not (non‐Candida‐onset group). The follow‐up periods were 67 (37–86) months in the Candida‐onset group and 55 (34–89) months in the non‐Candida‐onset group. Severe infection was defined as bacterial or fungal infection requiring hospitalization; viral infections were excluded.

Results

Severe infection developed in 9/25 (36%) patients in the Candida‐onset group and in 77/497 (15%) patients in the non‐Candida‐onset group (p = .006). Binomial logistic analysis revealed that Candida infection (odds ratio [OR] 2.53, 95% confidence interval [CI] 1.06–6.06; p = .037) and use of rituximab (OR 1.81, 95% CI 1.12–2.93; p = .016) were significant predictors of subsequent severe infection.

Conclusion

Oral/oesophageal candidiasis is a risk factor for severe infection after kidney transplantation and suggests an over‐immunosuppressive state, which should prompt evaluation of immunosuppression.

This paper concludes that oral/oesophageal candidiasis is a risk factor for severe infection following kidney transplantation. The authors suggest that the presence of oral/oesophageal candidiasis indicates an over‐immunosuppressed state, which should prompt a review of immunosuppression.

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.

Efficacy of clotrimazole for the management of oral candidiasis: A meta-analysis of randomized clinical trials

Purpose

To assess the efficacy and safety of topical application of clotrimazole versus others in the treatment of oropharyngeal candidiasis (OPC).

Method

Four electronic databases, registries of ongoing trials, and manual search were used to identify randomized controlled trials (RCTs) that compared the efficacy of clotrimazole to other antifungal agents in patients who were clinically diagnosed with oral candidiasis up to November 1st, 2019. Primary outcomes were clinical response and mycological cure rates. Secondary outcomes include relapse rate, incidence of systemic infections, and compliance. Adverse effects were also evaluated.

Results

Sixteen RCTs with a total of 1685 patients were included. Half of the eligible studies were considered at high risk of performance bias and more than a third, at high risk of reporting bias. Our analysis showed no significant difference in clinical response between clotrimazole and all other antifungal agents. However, clotrimazole was less effective in terms of mycologic cure and relapse rate. Sensitivity analysis comparing clotrimazole to other topical antifungal agents only showed no differences in clinical response, microbiologic cure or relapse. Further sensitivity analysis showed significant efficacy of fluconazole over clotrimazole.

Conclusion

This meta-analysis indicated that clotrimazole is less effective than fluconazole but as effective as other topical therapies in treating OPC. Well-designed high-quality RCT is needed to validate these findings.

Concurrent chronic hyperplastic candidosis and oral lichenoid lesion as adverse events of secukinumab therapy

Secukinumab (Cosentyx®) is an IL-17A inhibitor which is used for the management of psoriasis, active psoriatic arthritis or ankylosing spondylitis. Oral adverse events of secukinumab therapy are not widely appreciated. This article highlights the presentation of two concurrent oral adverse events of secukinumab therapy; namely chronic hyperplastic candidosis (CHC) and oral lichenoid lesion (OLL). This is the first documented case report of CHC occurring as a consequence of secukinumab therapy, and represents a new adverse effect which general and specialist oral health practitioners should be aware of. This case highlights the importance of correlating the presence of oral lesions with the patient's medical history, keeping up to date with the development of new medications and pharmacotherapeutics, having a deep understanding of underlying biological processes related to various oral diseases, and appreciating the use of clinical adjunctive devices. Accurate diagnosis is key to formulating a correct management plan.

Phytochemistry, antifungal and antioxidant activity, and cytotoxicity of byrsonima gardneriana (A. Juss) extract

OBJECTIVE

To determine the phytochemical composition of Byrsonima gardneriana (A. Juss) leaf extract (BGE) and its antifungal activity against Candida spp., antioxidant potential and in vitro cytotoxicity.

MATERIAL AND METHODS

BGE was obtained and submitted to Gas Chromatography Coupled to Mass Spectrometry for phytochemical analysis. The ethanolic extract was tested for its antifungal activity against C. albicans and non-albicans reference strains and clinical isolates in addition to inhibition of C. albicans growth kinetics. It was also tested for antioxidant potential in the presence of phenylhydrazine and reactive oxygen species (ROS). And cytoxicity in human erythrocytes. The data were analyzed by one-way Analysis of Variance (ANOVA) followed by Tukey's or Dunnett's post-hoc test, with α = 0.05.

RESULTS

Pyroglutamic acid (90.77 %), eucalyptol (89.61 %) and octanoic acid (76.22 %) were the major compounds detected in BGE, P (%) is the percent probability of compound identification, according to the mass spectra library. The extract showed fungistatic activity, with MIC of 125 μg/mL against most tested strains. While BGE showed low hemolytic activity on all blood types tested herein, it could not prevent osmotic stress in human erythrocytes. The extract did not have oxidizing effects in the presence of phenylhydrazine, but it showed antioxidant potential against ROS when tested at 31 μg/mL and 62 μg/mL.

CONCLUSION

B. gardneriana extract showed antifungal activity against Candida spp., demonstrated low hemolytic potential, no oxidant activity in human erythrocytes and antioxidant activity against ROS. This study opens avenues for the study of BGE as a promising biocompatible antifungal agent.

Efficacy of different formulations of nystatin in an experimental model of oral candidiasis in sialoadenectomized rats

BACKGROUND/PURPOSE

Oral candidiasis is the most common fungal infection of the oral cavity and has become a focus of attention in recent years because of its association with highly topical immunosuppressive conditions. The aims of this study were to determine the value of microbiological, clinical and histological parameters of Candida albicans colonisation of the dorsal tongue surface as indicators of disease severity, and to evaluate therapeutic response to different formulations of nystatin.

MATERIALS AND METHODS

We used 84 males, 2-month-old Sprague-Dawley sialoadenectomized rats. Different formulations of nystatin were used to evaluate the therapeutic response. The animals were randomized to 2 groups with each of 42 animals and received the experimental treatments from day 17-22.

RESULTS

100% of the rats showed evidence of infection. At 5 and 10 days of starting treatment with nystatin + chitosan, and at 10 days of starting nystatin + orabase, the number of animals with positive dorsal tongue culture decreased significantly (p < 0.05), acting the Nystatin + chitosan more rapidly against Candida. In the control group, the percentage of normal papillae on day 22 and 27 was 83.33% (SD = 1.50) and 79.08% (SD = 2.30), respectively. Significant differences were observed in the mean O'Grady score at 5 and 10 days (p < 0.0001).

CONCLUSION

The model has been shown to be effective in inducing infection, and that the combination of nystatin and chitosan yielded the best therapeutic outcomes at both 5 and 10 days after infection.

Evaluating the role of local host factors in the candidal colonization of oral cavity: A review update

Human oral cavity is home to a number of organisms, Candida albicans being one of them. This review article aims at understanding the correlation between the oral candidal colonization and the local host factors that may influence it with special emphasis on congenital craniofacial anomalies such as cleft lip and palate (CLP). Various scientific databases were searched online and relevant articles were selected based on the inclusion criteria. A comparative study was done to understand the interdependence of various factors (including CLP) and oral candidal colonization. The results revealed a strong association of certain local host factors which may influence the oral colonization of Candida species. Factors such as mucosal barrier, salivary constituents and quantity of saliva, congenital deformities like CLP, oral prostheses such as dentures/palatal obturators and fixed orthodontic appliances (FOAs) were identified. All these factors may directly affect the growth of Candida in the oral cavity. Although numerous studies have pointed a positive correlation between Oral Candidal colonization and local host factors such as oral prostheses, FOA, and oral mucosal barrier only one study has been done, in the Indian subcontinent with respect to the correlation of candidal colonization and CLP. After the evaluation of all the factors mentioned in various case studies, it can be concluded that the presence of local host factors such as orofacial clefts, dental prostheses, FOA, xerostomia, and atrophy of the oral mucous membrane lead to significant increase in candidal colonization, but since very few studies in regard to CLP have been done worldwide and in India, in particular, further studies are warranted.

Frequency of Candida Species in the Oral Cavity of Narcotics and Stimulants Smokers in Isfahan, Using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism Method

Background:

Candida species are a group of coexistent microorganisms in the oral cavity that opportunistically cause disease in vulnerable people, including addicts. This study is aimed at identifying and determining the frequency of Candida species in the oral cavity of the addicts to inform the epidemiological panel and to warn to prevent the resistance of the species.

Materials and Methods:

In this study, sampling was done from the oral cavity of 83 addicts who referred to Addiction Treatment Centers in Isfahan, Iran, using moist sterile swab. The presence of yeast on the direct microscope slides of 58 samples was confirmed. To carry out culture and the primary identification, Sabouraud dextrose agar medium with chloramphenicol as well as HiCrome Candida agar medium was used. Isolates were identified by polymerase chain reaction (PCR) restriction fragment length polymorphism (using specific primers ITS1-ITS4 and MSP I enzyme) and Duplex PCR test (using specific primers CDU1-CDU2/CAL1-CAL2).

Results:

Out of 93 Candida isolates which had been isolated from 58 culture-positive samples of the oral cavity, Candida albicans (41.93%) were the most prevalent species, followed by Candida dubliniensis (24.73%), Candida glabrata (21.50%), Candida kefyr (8.60%), Candida tropicalis (2.15%), and Candida parapsilosis (1.07%), respectively. In 33 cases (56.90%), the presence of more than one Candida species was observed.

Conclusion:

Compared to the studies conducted on the oral cavity of healthy controls, smoking certain drugs can have a significant effect on the presence and frequency of Candida species, particularly C. dubliniensis and C. glabrata.

Dental Considerations in Patients with Oral Mucosal Diseases

Oral mucosal diseases represent a significant health care burden, rendering a complex patient population in which interdisciplinary care among dermatologists, primary dental providers, and dental specialists is required for optimal care. Oral mucosal diseases often cause painful ulceration and blistering which can impede a patient's ability to perform dental home care and the dental professional's ability to deliver routine and complex treatment. It is crucial to consider the environment of the oral cavity. It is paramount to be aware of the potential side effects that certain medications may cause and the possible interactions with other medications the patient is using.

Chronic Oral Lesions

Chronic oral mucosal lesions can be associated with several mucocutaneous diseases. This article reviews the autoimmune and immune-mediated, reactive, genetic, and infectious diseases that may present with chronic oral and/or cutaneous manifestations and provides a rational approach to diagnosis and management.

Effects of two peroxide enzymatic denture cleaners on Candida albicans biofilms and denture surface

Objective

To compare the antifungal action of two commercially available denture cleaning agents to that of standard clinical solutions, and determine their effects on the polymethyl methacrylate (PMMA) acrylic resin denture surface.

Methods

Candida albicans growth was analyzed by colony forming assay, and the methyl thiazolyl tetrazolium (MTT) assay was used to evaluate biofilm formation and cell adhesion. The morphology and roughness of PMMA acrylic resin surface was measured by scanning electron microscopy (SEM) images and stylus method.

Results

Clene®, Polident® and 3% NaHCO₃ solutions showed significantly greater antifungal effects in terms of both inhibiting growth and biofilm formation. In addition, Clene® solution prevented adhesion of C. albicans on cell culture plates compared to filter-sterile tap water, whereas other reagents did not have an inhibitory effect. One-month immersion in the different cleaning reagents significantly inhibited fungal adhesion on the PMMA surface Clene®, Polident® and 3% NaHCO₃ showed greater effect compared to PBS and filter-sterile tap water. Finally, none of the cleansing agents significantly affected the morphology and roughness of the PMMA surface.

Conclusion

Clene®, Polident® and 3% NaHCO₃ solutions can inhibit C. albicans growth and biofilm formation to some extent on cell culture plates, and significantly inhibit fungal adhesion on the PMMA surface without affecting surface morphology and roughness.

Oral Candidiasis: A Disease of Opportunity

Oral candidiasis, commonly referred to as “thrush,” is an opportunistic fungal infection that commonly affects the oral mucosa. The main causative agent, Candida albicans, is a highly versatile commensal organism that is well adapted to its human host; however, changes in the host microenvironment can promote the transition from one of commensalism to pathogen. This transition is heavily reliant on an impressive repertoire of virulence factors, most notably cell surface adhesins, proteolytic enzymes, morphologic switching, and the development of drug resistance. In the oral cavity, the co-adhesion of C. albicans with bacteria is crucial for its persistence, and a wide range of synergistic interactions with various oral species were described to enhance colonization in the host. As a frequent colonizer of the oral mucosa, the host immune response in the oral cavity is oriented toward a more tolerogenic state and, therefore, local innate immune defenses play a central role in maintaining Candida in its commensal state. Specifically, in addition to preventing Candida adherence to epithelial cells, saliva is enriched with anti-candidal peptides, considered to be part of the host innate immunity. The T helper 17 (Th17)-type adaptive immune response is mainly involved in mucosal host defenses, controlling initial growth of Candida and inhibiting subsequent tissue invasion. Animal models, most notably the mouse model of oropharyngeal candidiasis and the rat model of denture stomatitis, are instrumental in our understanding of Candida virulence factors and the factors leading to host susceptibility to infections. Given the continuing rise in development of resistance to the limited number of traditional antifungal agents, novel therapeutic strategies are directed toward identifying bioactive compounds that target pathogenic mechanisms to prevent C. albicans transition from harmless commensal to pathogen.

Viral, bacterial, and fungal infections of the oral mucosa: Types, incidence, predisposing factors, diagnostic algorithms, and management

For millions of years, microbiota residing within us, including those in the oral cavity, coexisted in a harmonious symbiotic fashion that provided a quintessential foundation for human health. It is now clear that disruption of such a healthy relationship leading to microbial dysbiosis causes a wide array of infections, ranging from localized, mild, superficial infections to deep, disseminated life-threatening diseases. With recent advances in research, diagnostics, and improved surveillance we are witnessing an array of emerging and re-emerging oral infections and orofacial manifestations of systemic infections. Orofacial infections may cause significant discomfort to the patients and unnecessary economic burden. Thus, the early recognition of such infections is paramount for holistic patient management, and oral clinicians have a critical role in recognizing, diagnosing, managing, and preventing either new or old orofacial infections. This paper aims to provide an update on current understanding of well-established and emerging viral, bacterial, and fungal infections manifesting in the human oral cavity.

The association between oral candidiasis and severity of chemoradiotherapy-induced dysphagia in head and neck cancer patients: A retrospective cohort study

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Oral candidiasis (OC) aggravated dysphagia in chemoradiation for HNC.

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OC patients required higher doses of opioids.

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Early diagnosis of chemoradiation-associated OC seems difficult.

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Antifungal prophylaxis may reduce the severity of mucositis and dysphagia.

Background and purpose

Concurrent chemoradiotherapy (CCRT) for head and neck cancer (HNC) is a risk factor for oral candidiasis (OC). As Candida spp. are highly virulent, we conducted a retrospective study to determine whether OC increases the severity of dysphagia related to mucositis in HNC patients.

Patients and methods

We retrospectively analyzed the cases of consecutive patients with carcinomas of the oral cavity, pharynx, and larynx who underwent CCRT containing cisplatin (CDDP) at our hospital. The diagnosis of OC was based on gross mucosal appearance. We performed a multivariate analysis to determine whether OC was associated with the development of grade 3 dysphagia in the Radiation Therapy Oncology Group (RTOG) Acute Toxicity Criteria. The maximum of the daily opioid doses was compared between the patients with and without OC.

Results

We identified 138 HNC patients. OC was observed in 51 patients (37%). By the time of their OC diagnosis, 19 (37%) had already developed grade 3 dysphagia. Among the 30 patients receiving antifungal therapy, 12 (40%) showed clinical deterioration. In the multivariate analysis, OC was independently associated with grade 3 dysphagia (OR 2.75; 95%CI 1.22–6.23; p = 0.015). The patients with OC required significantly higher morphine-equivalent doses of opioids (45 vs. 30 mg/day; p = 0.029).

Conclusion

Candida infection causes refractory dysphagia. It is worth investigating whether antifungal prophylaxis reduces severe dysphagia related to candidiasis.

Temperature-dependent mucosal permeation kinetics of stigmasterol microspheres: In vivo mice model antioral candidiasis study

Evaluation of mucosal permeation of stigmasterol from the glutaraldehyde cross linked chitosan microspheres at increasing experimental temperatures was performed. The activation energy of permeation, partition, and diffusion were estimated to understand the permeation kinetic with respect to the temperature. The formulation depicting least activation energy possessed the increased permeation thresholds of drug at the site of application. The encapsulation efficacy and mucoadhesive strength were found to be directly proportional to the polymer-emulsifier ratio. Decreased intensity in crystallography directed the molecular dispersion of microencapsulated drug. The depleted enthalpic phase transition in thermogram affirmed the stigmasterol encapsulation. The sphericity and the size of microspheres were determined by scanning electron photo micrograph. The in vivo quantification of oral Candida infection with different statistical approach and histopathological observation of infected tongue of mice on treatment with the stigmasterol encapsulated microspheres showed significant anti oral candidiasis activity by reduction of fungal colony count and recovery of papillae, reorganization of basal cell layer and newly formed papillae during 21-28 days of treatment.

Effect of Probiotics on Oral Candidiasis: A Systematic Review and Meta-Analysis

Oral candidiasis (OC) is an increasing health problem due to the introduction of new drugs, population aging, and increasing prevalence of chronic illness. This study systematically reviews the effects of the oral intake of probiotics, prebiotics, and synbiotics on Candida spp. counts (colony-forming units (CFU)/mL) in oral and palatal samples. A literature search was conducted. Twelve studies, eight randomized clinical trials (RCTs), and four pre-post studies, resulted as eligible for the meta-analysis, which was performed through a Bayesian random-effects model. All studies analyzed probiotics, and none of them analyzed prebiotics or synbiotics. The treatments effects were measured in terms of odds ratio (OR) of OC (CFU/mL >10², 10³, or 10⁴). The meta-analytic OR was 0.71 (95% credibility interval (CrI): 0.37, 1.32), indicating a beneficial effect of treatment; the I² index was 56.3%. Focusing only on RCTs, the OR was larger and more precise at 0.53 (95% CrI: 0.27, 0.93). The effect of treatment appeared to be larger on denture wearers. Our findings indicate that the intake of probiotics can have a beneficial effect on OC and that the effects could vary according to the patients' characteristics. Due to the presence of medium-high-risk studies, the results should be interpreted with caution.

Investigating Common Pathogenic Mechanisms between Homo sapiens and Different Strains of Candida albicans for Drug Design: Systems Biology Approach via Two-Sided NGS Data Identification

Candida albicans (C. albicans) is the most prevalent fungal species. Although it is a healthy microbiota, genetic and epigenetic alterations in host and pathogen, and microenvironment changes would lead to thrush, vaginal yeast infection, and even hematogenously disseminated infection. Despite the fact that cytotoxicity is well-characterized, few studies discuss the genome-wide genetic and epigenetic molecular mechanisms between host and C. albicans. The aim of this study is to identify drug targets and design a multiple-molecule drug to prevent the infection from C. albicans. To investigate the common and specific pathogenic mechanisms in human oral epithelial OKF6/TERT-2 cells during the C. albicans infection in different strains, systems modeling and big databases mining were used to construct candidate host–pathogen genetic and epigenetic interspecies network (GEIN). System identification and system order detection are applied on two-sided next generation sequencing (NGS) data to build real host–pathogen cross-talk GEINs. Core host–pathogen cross-talk networks (HPCNs) are extracted by principal network projection (PNP) method. By comparing with core HPCNs in different strains of C. albicans, common pathogenic mechanisms were investigated and several drug targets were suggested as follows: orf19.5034 (YBP1) with the ability of anti-ROS; orf19.939 (NAM7), orf19.2087 (SAS2), orf19.1093 (FLO8) and orf19.1854 (HHF22) with high correlation to the hyphae growth and pathogen protein interaction; orf19.5585 (SAP5), orf19.5542 (SAP6) and orf19.4519 (SUV3) with the cause of biofilm formation. Eventually, five corresponding compounds—Tunicamycin, Terbinafine, Cerulenin, Tetracycline and Tetrandrine—with three known drugs could be considered as a potential multiple-molecule drug for therapeutic treatment of C. albicans.

Molecular characterization of Candida dubliniensis and Candida albicans in the oral cavity of drug abusers using duplex polymerase chain reaction

Background and Purpose:

Candida dubliniensis is closely related to the most pathogenic and prevalent yeast, namely C. albicans.Candida species can opportunistically overgrow in vulnerable individuals and cause a variety of diseases. The current study aimed to identify and isolate C. dubliniensis species present in the Candida albicans species complex identified in the oral cavity of drug abusers.

Materials and Methods:

This study was conducted on 53 strains of C. albicans species complex, isolated from the oral mucosa of drug abusers in Isfahan, Iran. DNA extraction was accomplished through boiling procedure. Duplex polymerase chain reaction (PCR) was performed to amplify ITS1-5.8S-ITS2 region using four specific primers. Fungal species were identified based on the difference in the size of the bands created in the Agarose gel.

Results:

Out of the 53 isolates under study, 30 (56.6%) and 14 (26.4%) samples were identified as C. albicans and C. dubliniensis, respectively. In the remaining 9 samples (17%), both types of Candida species were confirmed.

Conclusion:

The findings of the present study revealed the presence of a noticeable amount of C. dubliniensis in the oral cavity of drug abusers. Therefore, the probable presence of this fungus should be considered during the examination of oral infection among this group. To date, no research has directly investigated this issue in Iran.

Candida is a protractive factor of chronic oral ulcers among usual outpatients

Although many oral ulcers have similar clinical appearances, their etiologies can range from reactive to neoplastic to oral manifestations of dermatological diseases. In patients with an HIV infection, fungal diseases may cause ulceration in the oral cavity; however, there have been few studies of oral ulcerative lesions associated with Candida in patients without an HIV infection. Nevertheless, we encountered chronic oral ulcer associated with Candida among our frequent outpatients without an HIV infection. The present article reviews the causes of oral ulcers, focusing on Candida as a protractive factor for chronic oral ulcers, and it is recommended that Candida involvement be considered in diagnosis of a certain chronic oral ulcer, that remains of unknown origin even if some examinations have been performed.

Candidal Species Identification in Malignant and Potentially Malignant Oral Lesions with Antifungal Resistance Patterns

Objective:

Candidal species identification in malignant and potentially malignant oral lesions with antifungal susceptibility.

Materials and Methods:

Oral candidal carriage, strain diversity, and antifungal susceptibility of Candida were checked for the patients having oral cancer or precancer reporting to the clinics for 1½ year. Statistically significant patients were selected and a control group was taken. A total of 105 individuals were selected and divided into three different groups. Salivary samples were taken from all the individuals. Candida detection was done using Sabouraud's agar and candidal species detection on CHROMagar. In vitro antifungal sensitivity was done using antifungal disc diffusion method.

Results:

Candida was isolated from 88.6% of patients with oral cancer and 45.7% in oral precancerous group. C. albicans was the predominant species found in 100% of oral precancerous and 71% in oral cancerous patients. Other Candid a species found were C. tropicalis (9.7%) and C. krusei (19.6%). Antifungal susceptibility showed 4.3% sensitivity to fluconazole and 100% sensitivity to amphotericin B and nystatin.

Conclusion:

Oral Candida carriage was higher in oral cancerous group and majority of them were sensitive to amphotericin B and nystatin.

Oral mycoses in avian scavengers exposed to antibiotics from livestock farming

The exposure to antimicrobial pharmaceuticals as environmental contaminants can exert direct and indirect detrimental effects on health of wildlife. Fungal infections pose a major threat to domestic, captive-housed wild and free-ranging wild animals worldwide. However, little is known about their role in disease in birds in the wild. Here, we evaluated the incidence of thrush-like lesions in the oral cavity of wild nestling cinereous vultures (Aegypius monachus), griffon vultures (Gyps fulvus), Egyptian vultures (Neophron percnopterus) and golden eagles (Aquila chrysaetos) exposed to veterinary antibiotics via the consumption of medicated livestock carcasses. Lesions, which varied in number, size and location, were more frequent in the cinereous (77.8%, n=9) and griffon vultures (66.7%, n=48) than in the Egyptian vultures (28.6%, n=21) and golden eagles (28.6%, n=7). In all individuals (100%, n=24) of a subsample of the affected nestlings, yeast species were isolated from thrush-like oral lesions and identified using a well-established system based on their carbohydrate assimilation profiles and other complementary tests. Fourteen yeast species from seven genera (Candida, Meyerozyma, Pichia, Yarrowia, Cryptococcus, Rhodotorula and Trichosporon) were isolated from the lesions of the four host species. We found differential infections and effects depending on host age-related exposure or susceptibility to different yeast species across the development of nestling griffon vultures. This unprecedented outbreak of oral mycoses is alarming because of the delicate conservation status of several of the affected species. The role of livestock antibiotics in the transition of yeast species from commensal to opportunistic pathogens should be evaluated in an attempt to avoid the detrimental effects of contamination and disease on host health, as well as on the transmission of fungal emerging pathogens among wildlife populations and species, and their dissemination across livestock and human populations.

Quantification of carious pathogens in the interdental microbiota of young caries-free adults

Background

The majority of caries lesions in adults occur on the proximal tooth surfaces of the posterior teeth. A comprehensive study of the composition of the oral microbiota is fundamental for a better understanding of the etiology of interdental caries.

Methods

Twenty-five caries-free subjects (20–35 years old) were enrolled in the study. The interdental biofilm of four interdental sites were collected. The real-time polymerase chain reaction (PCR) methodology were used to quantify (i) the following bacteria: Streptococcus spp., Streptococcus mutans, Lactobacillus spp., Enterococcus spp., and Enterococcus faecalis; (ii) the fungus Candida albicans; and (iii) total bacteria.

Results

Streptococcus spp. was the most abundant species, followed by Lactobacillus spp. and Enterococcus spp. Streptococcus spp. and Lactobacillus spp. were detected at all tested sites and Enterococcus spp. at 99% of sites. S. mutans was detected at only 28% of the tested sites and C. albicans was detected at 11% of sites. E. faecalis was never detected. In 54.5% of the biofilm inhabited by C. albicans, S. mutans was present. Moreover, 28% of the ID sites co-expressed S. mutans and Lactobacillus spp. The studied pathogens were organized into two correlated groups of species. Strikingly, the fungus C. albicans and the bacteria Enterococcus spp. cluster together, whereas Streptococcus spp., S. mutans and Lactobacillus spp. form one distinct cluster.

Conclusion

The interdental biofilm of young caries-free adults is comprised of pathogens that are able to induce interproximal caries. That several of these pathogens are implicated in heart disease or other systemic diseases is an argument for the disruption of interdental biofilms using daily oral hygiene.

Induction of Severe Chronic Hyperplastic Candidiasis in Rat by Opportunistic Infection of C. albicans through Combination of Diabetes and Intermittent Prednisolone Administration

Chronic hyperplastic candidiasis progresses from squamous cell hyperplasia to squamous cell carcinoma (SCC); however, the oncogenic mechanism remains unclear. In the present study, we attempted to induce opportunistic Candida albicans infection and establish chronic hyperplastic candidiasis in rats by combining diabetic condition and prednisolone administration, followed by analysis of the inflammatory cells involved in the disease progression. Female Wistar Bunn/Kobori (WBN/Kob) rats were divided into 3 groups: alloxan-induced diabetic rats (A group) along with diabetic (AP group) and nondiabetic (P group) rats intermittently treated with prednisolone. Animals were euthanized at 42 weeks of age. Squamous cell hyperplasia following C. albicans infection in the forestomach was observed in almost all AP and A group rats. The lesions in the AP group were significantly more severe than those in the A group. In addition, SCC was detected in 1 AP group animal. Cluster of differentiation (CD)4-positive T cell and CD68-positive macrophage infiltration in the AP group was significantly stronger than that in the A group. These findings suggest that the combination of diabetes and intermittent prednisolone administration could induce chronic hyperplastic candidiasis without direct C. albicans inoculation and that CD4-positive T cells and CD68-positive macrophages may be highly involved in the pathogenesis of these hyperplastic lesions.

Metabolic Interactions between Bacteria and Fungi in Commensal Oral Biofilms

Oral health is more than just the absence of disease. The key to oral health is a diverse microbiome in an ecological balance. The oral microbiota is one of the most complex and diverse microbial communities in the human body. To maintain oral health, balance between the human host and the intrinsic microorganisms is essential. The healthy oral cavity is represented by a great microbial diversity, including both bacteria and fungi. The bacterial microbiome is very well studied. In contrast, fungi inhabiting the oral cavity are often overlooked. All microbial species in the oral cavity form communities which establish a variety of micro-niches and inter- and intra-species interactions. These interactions can be classified into three main groups: physical, chemical and metabolic interactions. Different metabolic interactions are reviewed in this report, among which are the metabolism of sugars, carbon, lactate and oxygen. This review set out with the aim of assessing the importance of metabolic interactions between fungi and bacteria in the healthy oral cavity.

The essential oil of Allium sativum as an alternative agent against Candida isolated from dental prostheses

BACKGROUND

The colonization of the surfaces of dental prostheses by Candida albicans is associated with the development of denture stomatitis. In this context, the use of fluconazole has been proposed, but its disadvantage is microbial resistance. Meanwhile, the oil of Allium sativum has shown an effect in controlling biofilm formation by C. albicans.

AIMS

The objective of this study was to determine the antifungal activities of the essential oil of A. sativum and fluconazole against clinical isolates of Candida species obtained from rigid, acrylic-based partial or total dentures and to compare these agents' effects on both biofilm and planktonic cells.

METHODS

A total of 48 clinical isolates obtained from the acrylic surface of partial or complete dentures were examined, and the following species were identified: C. albicans, Candida glabrata, Candida tropicalis, and Candida krusei. For each isolate, the antifungal activities of the essential oil of A. sativum and fluconazole against both biofilm and planktonic cells were evaluated using the Clinical & Laboratory Standards Institute (CLSI) M27-A3 method. The isolates were also evaluated by semiquantitative XTT reduction.

RESULTS

All planktonic Candida isolates were susceptible to the essential oil of A. sativum, whereas 4.2% were resistant to fluconazole. Regarding susceptibilities in biofilms, 43.8% of biofilms were resistant to A. sativum oil, and 91.7% were resistant to fluconazole.

CONCLUSIONS

All planktonic cells of the different Candida species tested are susceptible to <1mg/ml A. sativum oil, and the majority are susceptible to fluconazole. Susceptibility decreases in biofilm cells, with increased resistance to fluconazole compared with A. sativum oil. The essential oil of A. sativum is thus active against clinical isolates of Candida species obtained from dentures, with effects on both biofilm and planktonic cells in vitro.

A Comparative Study: Taxonomic Grouping of Alkaline Protease Producing Bacilli

Alkaline proteases have biotechnological importance due to their activity and stability at alkaline pH. 56 bacteria, capable of growing under alkaline conditions were isolated and their alkaline protease activities were carried out at different parameters to determine their optimum alkaline protease production conditions. Seven isolates were showed higher alkaline protease production capacity than the reference strains. The highest alkaline protease producing isolates (103125 U/g), E114 and C265, were identified as Bacillus licheniformis with 99.4% and Bacillus mojavensis 99.8% based on 16S rRNA gene sequence similarities, respectively. Interestingly, the isolates identified as Bacillus safensis were also found to be high alkaline protease producing strains. Genotypic characterizations of the isolates were also determined by using a wide range of molecular techniques (ARDRA, ITS-PCR, (GTG)5-PCR, BOX-PCR). These different techniques allowed us to differentiate the alkaliphilic isolates and the results were in concurrence with phylogenetic analyses of the 16S rRNA genes. While ITS-PCR provided the highest correlation with 16S rRNA groups, (GTG)5-PCR showed the highest differentiation at species and intra-species level. In this study, each of the biotechnologically valuable alkaline protease producing isolates was grouped into their taxonomic positions with multi-genotypic analyses.

Nigella sativa and its active constituent thymoquinone in oral health

In this review, we summarized published reports that investigated the role of Nigella sativa (NS) and its active constituent, thymoquinone (TQ) in oral health and disease management. The literature studies were preliminary and scanty, but the results revealed that black seed plants have a potential therapeutic effect for oral and dental diseases. Such results are encouraging for the incorporation of these plants in dental therapeutics and hygiene products. However, further detailed preclinical and clinical studies at the cellular and molecular levels are required to investigate the mechanisms of action of NS and its constituents, particularly TQ.