Urban legends series: oral candidosis

Appropriateness of antimicrobial prescribing for oral and dental conditions in Australian hospitals: 2013 to 2022

OBJECTIVES

Dentists manage a variety of oral infections in clinical practice. Inappropriate antimicrobial prescribing by dentists occurs frequently and antimicrobial stewardship strategies should include dentistry. The aim of this retrospective analysis of the Australian Hospital National Antimicrobial Prescribing Survey (Hospital NAPS) dataset, was to describe the types of oral and dental indications where antimicrobials were prescribed, and assess the guideline compliance and appropriateness of the antimicrobials in Australian hospitals.

METHODS

Data from the Hospital NAPS was extracted for oral and dental indications from 2013 to 2022. The types of oral and dental indications presented, and the corresponding antimicrobials prescribed were assessed for compliance according to national prescribing guidelines, and appropriateness according to the NAPS structured algorithm.

RESULTS

A total of 8,001 prescriptions for 7,477 patients were identified, from 433 hospitals. Antifungal, antibiotic and antiviral agents accounted for 84.5 %, 15.4 % and 0.03 % of prescriptions respectively. A greater proportion of antibiotics were prescribed in regional and rural areas compared to antifungals. The prescriptions assessed as compliant were 80.0 % and 44.7 % of antifungals and antibiotics respectively. Prescriptions assessed as appropriate were 84.4 % of antifungals, and 65.3 % of antibiotic prescriptions.

CONCLUSIONS

A wide variety of antimicrobials were used with moderate levels of compliance and appropriateness. Future interventions should include targeted education, utilisation of prescribing guidelines, and tools to diagnose and manage oral and dental conditions. Consideration can be given to adjustment of the Hospital NAPS tool to cater for oral conditions and include the provision of dental treatment in the management of these infections.

CLINICAL SIGNIFICANCE

A wide variety of oral and dental conditions are presented in Australian hospital settings, managed by a range of antibiotics and antifungals, with moderate levels of compliance to guidelines and appropriateness. Antimicrobial stewardship strategies should target and support dentistry in hospital settings.

Functional Characterization of a Bacillus-Derived Novel Broad-Spectrum Antifungal Lipopeptide Variant against Candida tropicalis and Candida auris and Unravelling Its Mode of Action

Limited treatment options, recalcitrance, and resistance to existing therapeutics encourage the discovery of novel antifungal leads for alternative therapeutics. Antifungal lipopeptides have emerged as potential candidates for developing new and alternative antifungal therapies. In our previous studies, we isolated and identified the lipopeptide variant AF4 and purified it to homogeneity via chromatography from the cell-free supernatant of Bacillus subtilis. AF4 was found to have broad-spectrum antifungal activity against more than 110 fungal isolates. In this study, we found that clinical isolates of Candida tropicalis and Candida auris exposed to AF4 exhibited low MICs of 4 to 8 mg/L. Time-kill assays indicated the in vitro pharmacodynamic potential of AF4. Biocompatibility assays demonstrated ~75% cell viability at 8 mg/L of AF4, indicating the lipopeptide's minimally cytotoxic nature. In lipopeptide-treated C. tropicalis and C. auris cells, scanning electron microscopy revealed damage to the cell surface, while confocal microscopy with acridine orange(AO)/propidium iodide (PI) and FUN-1 indicated permeabilization of the cell membrane, and DNA damage upon DAPI (4',6-diamidino-2-phenylindole) staining. These observations were corroborated using flow cytometry (FC) in which propidium iodide, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA), and rhodamine 123 (Rh123) staining of cells treated with AF4 revealed loss of membrane integrity, increased reactive oxygen species (ROS) production, and mitochondrial membrane dysfunction, respectively. Membrane perturbation was also observed in the 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence study and the interaction with ergosterol was observed by an ergosterol binding assay. Decreased membrane dipole potential also indicated the probable binding of lipopeptide to the cell membrane. Collectively, these findings describe the mode of action of AF4 against fungal isolates by membrane disruption and ROS generation, demonstrating its antifungal potency. IMPORTANCE C. tropicalis is a major concern for candidiasis in India and C. auris has emerged as a resistant yeast causing difficult-to-treat infections. Currently, amphotericin B (AMB) and 5-flucytosine (5-FC) are the main therapeutics for systemic fungal infections; however, the nephrotoxicity of AMB and resistance to 5-FC is a serious concern. Antifungal lead molecules with low adverse effects are the need of the hour. In this study, we briefly describe the antifungal potential of the AF4 lipopeptide and its mode of action using microscopy, flow cytometry, and fluorescence-based assays. Our investigation reveals the basic mode of action of the investigated lipopeptide. This lipopeptide with broad-spectrum antifungal potency is apparently membrane-active, and there is a smaller chance that organisms exposed to such a compound will develop drug resistance. It could potentially act as a lead molecule for the development of an alternative antifungal agent to combat candidiasis.

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.

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.

A single-center prospective pilot open-label study to assess the efficacy of topical application of an oxygen-enriched oil for the treatment of angular cheilitis

PURPOSE

The aim of this pilot study was to clarify the acceptability and clinical efficacy of an oxygen-enriched oil-based gel for treatment of angular cheilitis.

METHODS

A class IIb medical preparation, packaged in appropriate syringes, was tested. Patients were instructed how to use the gel for 10 days: finger rub application (3 times daily) on the dried lesion after meals, without eating, drinking, or speaking for at least 30 min thereafter. The Wilcoxon signed-rank test was used to assess whether there were any differences in the distributions of reported pain and lesion dimension. A microbiological examination was also performed with oral swabs; chi-squared test was used to compare the difference in the presence of microorganisms before and after treatment.

RESULTS

Thirty patients were treated. A significant improvement in reported outcome and a significant reduction in the initially measured largest dimension of the lesion were observed after use of the clinical protocol. Additionally, a significant reduction in the pathogen count was found.

CONCLUSION

Even if with limitations, data showed that this medical preparation facilitated prompt recovery from reported pain, without adverse reactions. Further work with a larger study population, and possibly a randomized control medication, will be needed.

Oral Candida Infection in Psoriatic Patients Treated with IL17A Inhibitors: Report of 3 Cases and a Comprehensive Review of the Literature

An intact and fully functional immune system plays a crucial role in the prevention of several infectious diseases. Interleukin (IL)17 is significantly involved in oral mucosa immunity against several antigens and microorganisms, including Candida albicans (CA). Herein, we present three cases of oral candidiasis (OC) related to the use of an IL17A inhibitor for psoriasis. Three psoriatic individuals presented for evaluation of widespread symptomatic oral lesions temporally correlated with the onset of IL17A inhibitors (secukinumab in two patients and brodalumab in one patient). Clinical examination revealed either partially removable white plaques in an erythematous background (case #1) or diffuse erythematous lesions (cases #2 and 3) involving several areas of the oral mucosa. Cytology smear, accompanied by histopathologic examination in case #1, confirmed the clinical impression of OC in all three cases. All patients received antifungal therapy with satisfactory clinical response. No discontinuation of the antipsoriatic regimen was recommended, but all patients were advised to remain under monitoring for possible OC relapses. During the last few years, new systemic biologic agents targeting IL17 have been used for the management of variable immune-mediated diseases. Few clinical trials and scarce case reports have shown that these medications place individuals at high risk of developing candidiasis. We propose that patients treated with these medications should be at close monitoring for the development of OC and, if it occurs, receive appropriate management.

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.

Therapeutic tools for oral candidiasis: Current and new antifungal drugs

BACKGROUND

Candidiasis is one of the most common opportunistic oral infections that presents different acute and chronic clinical presentations with diverse diagnostic and therapeutic approaches. The present study carries out a bibliographic review on the therapeutic tools available against oral candidiasis and their usefulness in each clinical situation.

MATERIAL AND METHODS

Recent studies on treatment of oral candidiasis were retrieved from PubMed and Cochrane Library.

RESULTS

Nystatin and miconazole are the most commonly used topical antifungal drugs. Both antifungal drugs are very effective but need a long time of use to eradicate the infection. The pharmacological presentations of miconazole are more comfortable for patients but this drug may interact with other drugs and this fact should be assessed before use. Other topical alternatives for oral candidiasis, such as amphotericin B or clotrimazole, are not available in many countries. Oral fluconazole is effective in treating oral candidiasis that does not respond to topical treatment. Other systemic treatment alternatives, oral or intravenous, less used are itraconazole, voriconazole or posaconazole. Available novelties include echinocandins (anidulafungin, caspofungin) and isavuconazole. Echinocandins can only be used intravenously. Isavuconazole is available for oral and intravenous use. Other hopeful alternatives are new drugs, such as ibrexafungerp, or the use of antibodies, cytokines and antimicrobial peptides.

CONCLUSIONS

Nystatin, miconazole, and fluconazole are very effective for treating oral candidiasis. There are systemic alternatives for treating recalcitrant infections, such as the new triazoles, echinocandins, or lipidic presentations of amphotericin B.

Antimicrobial effect on Candida albicans biofilm by application of different wavelengths and dyes and the synthetic killer decapeptide KP

The aim of this study was to test the application in vitro of different laser wavelengths at a low fluence in combination or not with proper photosensitizing dyes on Candida albicans biofilm with or without a synthetic killer decapeptide (KP). Candida albicans SC5314 was grown on Sabouraud dextrose agar plates at 37°C for 24 h. Cells were suspended in RPMI 1640 buffered with MOPS and cultured directly on the flat bottom of 96-wells plates. The previously described killer decapeptide KP was used in this study. Three different combinations of wavelengths and dyes were applied, laser irradiation has been performed at a fluence of 10 J/cm². The effect on C. albicans biofilm was evaluated by the XTT assay. Microscopic observations were realized by fluorescence optic microscopy with calcofluor white and propidium iodide. Compared with control, no inhibition of C. albicans biofilm viability was obtained with application of red, blue and green lasers alone or with any combination of red diode laser, toluidine blue and KP. The combined application of blue diode laser with curcumin and/or KP showed always a very significant inhibition, as curcumin alone and the combination of curcumin and KP did, while combination of blue diode laser and KP gave a less significant inhibition, the same obtained with KP alone. The combined application of green diode laser with erythrosine and/or KP showed always a very significant inhibition, as the combination of erythrosine and KP did, but no difference was observed with respect to the treatment with erythrosine alone. Again, combination of green diode laser and KP gave a significant inhibition, although paradoxically lower than the one obtained with KP alone. Treatment with KP alone, while reducing biofilm viability did not cause C. albicans death in the adopted experimental conditions. On the contrary, combined treatment with blue laser, curcumin and KP, as well as green laser, erythrosine and KP led to death most C. albicans cells. The combination of laser light at a fluence of 10 J/cm² and the appropriate photosensitizing agent, together with the use of KP, proved to exert differential effects on C. albicans biofilm.

Prevalence of Candida Species in Endodontic Infections: Systematic Review and Meta-analysis

INTRODUCTION

Candida in endodontic infections has been investigated in a large number of studies, but its role as an endodontic pathogen is still debatable. The aim of this study was to systematically review the literature on the prevalence of Candida species in root canal infections.

METHODS

Extensive literature research was performed in the most important electronic biomedical databases, and additional studies have been identified from references from relevant articles. Studies were critically appraised using a modified version of the Joanna Briggs Institute Critical Appraisal Checklist.

RESULTS

From 2225 unique records, 2118 were excluded on the basis of title and abstract. Of the remaining 107 studies, 50 were excluded after full-text review, and 57 were included for qualitative and quantitative analysis. The overall prevalence of Candida spp. in root canal infections was 8.20% (95% confidence interval, 5.56%-11.21%). Candida albicans was the most frequently isolated species. Significant heterogeneity among studies was observed (P < .001, I² = 86.07%). Subgroup analyses revealed a higher prevalence of Candida spp. from African samples. All studies considered, a high or unclear risk of bias was prevalent regarding 6 out of the 8 items considered in the critical appraisal.

CONCLUSIONS

Candida spp. occurred in a small proportion of root canal infections. Further and better designed research is needed to investigate the real contribution of Candida spp. to the microbial ecology in infected root canals.

Oral candidal carriage in asymptomatic patients

BACKGROUND

Interest in the association between oral cancer risk and Candida-associated promotion of mucosal dysplasia continues. However, little is known of the presence and amount of oral yeast in the mouths of healthy patients without mucosal lesions. The purpose of this prospective cross-sectional clinical study was to ascertain the prevalence and degree of carriage of Candida in the oral cavities of a non-cancer population, with reference to a range of parameters affecting the oral environment.

METHODS

Oral rinse samples were collected from a sample of 203 patients attending the Royal Dental Hospital of Melbourne and analysed for the presence and degree of colonization of yeast species that were phenotypically identified as albicans and non-albicans species.

RESULTS

Oral yeast carriage was found in 98/203 patients (48.3%), and of these, 83 (84.7%) patients carried C. albicans. There was no statistical difference in carriage when comparing gender, age, or presence of a removable prosthesis.

CONCLUSIONS

Both smoking and the presence of active carious lesions were found to be positively correlated with the carriage of oral Candida. Individuals who are current smokers are nearly seven times more likely to have oral Candida, and participants with high candidal colonization are more likely to be current smokers. Participants with active carious lesions were also more likely to carry oral Candida.

Polymicrobial biofilm formation by Candida albicans, Actinomyces naeslundii, and Streptococcus mutans is Candida albicans strain and medium dependent

Oral biofilms comprise of extracellular polysaccharides and polymicrobial microorganisms. The objective of this study was to determine the effect of polymicrobial interactions of Candida albicans, Actinomyces naeslundii, and Streptococcus mutans on biofilm formation with the hypotheses that biofilm biomass and metabolic activity are both C. albicans strain and growth medium dependent. To study monospecific biofilms, C. albicans, A. naeslundii, and S. mutans were inoculated into artificial saliva medium (ASM) and RPMI-1640 in separate vials, whereas to study polymicrobial biofilm formation, the inoculum containing microorganisms was prepared in the same vial prior inoculation into a 96-well plate followed by 72 hours incubation. Finally, biofilm biomass and metabolic activity were measured using crystal violet and XTT assays, respectively. Our results showed variability of monospecies and polymicrobial biofilm biomass between C. albicans strains and growth medium. Based on cut-offs, out of 32, seven RPMI-grown biofilms had high biofilm biomass (HBB), whereas, in ASM-grown biofilms, 14 out of 32 were HBB. Of the 32 biofilms grown in RPMI-1640, 21 were high metabolic activity (HMA), whereas in ASM, there was no biofilm had HMA. Significant differences were observed between ASM and RPMI-grown biofilms with respect to metabolic activity (P <01). In conclusion, biofilm biomass and metabolic activity were both C. albicans strain and growth medium dependent.

Current treatment of oral candidiasis: A literature review

Candidiasis or oral candidosis is one of the most common human opportunistic fungal infections of the oral cavity. This pathology has a wide variety of treatment which has been studied until these days. The present study offers a literature review on the treatment of oral candidiasis, with the purpose of establish which treatment is the most suitable in each case. Searching the 24 latest articles about treatment of candidiasis it concluded that the incidence depends on the type of the candidiasis and the virulence of the infection. Although nystatin and amphotericin b were the most drugs used locally, fluconazole oral suspension is proving to be a very effective drug in the treatment of oral candidiasis. Fluconazole was found to be the drug of choice as a systemic treatment of oral candidiasis. Due to its good antifungal properties, its high acceptance of the patient and its efficacy compared with other antifungal drugs. But this drug is not always effective, so we need to evaluate and distinguish others like itraconazole or ketoconazole, in that cases when Candida strains resist to fluconazole.

Key words:Candidiasis, treatment, miconazole, fluconazole, nystatin.

Gaining More Insight into the Determinants of Candida Species Pathogenicity in the Oral Cavity

Candida infection (candidiasis) is potentially life threatening and can occur in almost all anatomical sites, including the mouth. Candida species are in fact the most common fungal pathogens isolated from the oral cavity and frequently cause superficial infections such as oral candidiasis and denture-associated erythematous stomatitis. Whilst systemic dissemination of Candida from intraoral foci is rare and largely due to severe deficits of the host immune defenses, the development of localized oral candidiasis is most commonly related to a variety of non-immune determinants such as Candida virulence factors and permissive oral microenvironment. In particular, phenotypic switching and dental biofilm have emerged as major determinants for the pathogenicity of Candida and are currently the subject of intense research. An understanding of the molecular aspects underlying the biological behavior of Candida will be the key to the development of effective preventive as well as therapeutic measures for invasive and oral candidiasis.

Update on oral fungal infections

The incidence of oral fungal infections has increased in recent years as a result of factors such as increased number of solid organ transplantations and the widespread use of immunosuppressive drug therapies. This article reviews the diagnosis and treatment of oral fungal infections. At one time oral fungal infections were a relatively uncommon event, but with advances in health care and polypharmacy in an increasingly aging population, these infections are becoming a more routine clinical finding. The dental practitioner therefore needs to be familiar with the diagnosis and management of oral fungal infections.

In-vitro Analysis of Antifungal Activity of Epigallocatechin-Gallate: Preliminary Study

Oral candisosis is an heterogeneous group of diseases, caused by different species of Candida fungus. The incidence of drug-resistant species is increasing dramatically; furthermore, in recent years higher incidences of non-albicans and antimycotic-resistant species of Candida have been reported, thus increasing necessity of a non-antibiotic agent, which should be both highly effective and safe. It has been showed that the main polyphenols component of green tea, epigallocatechin-gallate (EGCG), has antibacterial activity; recently, it has been reported its antifungal activity too. We tested the effectiveness of a 0.20% EGCG (TEAVIGO®) gel, a non-pharmaceutical product suitable for oral in vivo use, on four species of Candida yeast (C.albicans, Cparapsilosis, C.tropicalis, C.glabrata), evaluating its antifungal activity and its capacity to inhibit biofilm formation. The EGCG gel showed a remarkable activity against C. parapsilosis and C. tropicalis. This preliminary study confirms EGCG effectiveness on fungi; for this reason, a product with such a low concentration of EGCG could be used with no side-effect for every-day oral hygiene. Anyway, mechanisms of antifungal activity of EGCG are not comprehended and need further studies to better understand the reasons of some Candida species' resistance.